Journal articles: 'Recombinant Salmonella vaccine'

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Kraehenbuhl, J. P., I. Corthésy-Theulaz, and D. Nardelli-Haefliger. "Recombinant Salmonella as vaccine carriers." Research in Immunology 149, no. 1 (January 1998): 87–90. http://dx.doi.org/10.1016/s0923-2494(98)80054-0.

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Bradley, Mark P., Lyn A. Hinds, and Peter H. Bird. "A bait-delivered immunocontraceptive vaccine for the European red fox (Vulpes vulpes) by the year 2002?" Reproduction, Fertility and Development 9, no. 1 (1997): 111. http://dx.doi.org/10.1071/r96066.

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An orally-delivered immunocontraceptive vaccine is being developed for the control of fox populations. A number of genes (PH-20, LDH-C4, ZP3) encoding gamete proteins have been cloned, produced in recombinant expression systems and used in fertility trials to test the efficacy of these antigens. As the immunocontraceptive vaccine will be delivered in a bait, there is a requirement for a greater understanding of the immune responses of the reproductive mucosa in canids, and the assessment of the best vaccine delivery system that will evoke a mucosal antibody response. Several vaccine delivery systems including microencapsulated antigens, and both vaccinia virus and bacterial vectors are being investigated. Oral administration of Salmonella typhimurium recombinants expressing different fox sperm antigens stimulates both systemic IgG responses to the antigen and a mucosal immune response within the female reproductive tract in the fox, indicating that salmonella may have potential with respect to the oral delivery of antigen. The enhancement of mucosal immune responses to orally-delivered vaccines is also being examined, research focussing on the possible use of fox-specific cytokines or the β-subunit of cholera toxin in forming part of the vaccine construct.

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Husseiny, Mohamed I., and Michael Hensel. "Rapid Method for the Construction of Salmonella enterica Serovar Typhimurium Vaccine Carrier Strains." Infection and Immunity 73, no. 3 (March 2005): 1598–605. http://dx.doi.org/10.1128/iai.73.3.1598-1605.2005.

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ABSTRACT Salmonella enterica serovar Typhimurium is a versatile organism for the generation of live recombinant vaccines for mucosal immunization. Various strategies have been devised for the stable and efficient expression of heterologous antigens by attenuated S. enterica strains, but these methods often require complex manipulations. Use of phage λ Red recombinase has recently been devised for gene replacements in Escherichia coli and S. enterica after introduction of PCR products. Based on this method, we have developed an approach that allows the integration of recombinant expression cassettes for heterologous antigens in a single step. The recombinant construct is integrated into the chromosome and is devoid of any selective marker such as antibiotic resistance. We observed the stable expression of model antigens without selective pressure. In addition, the method allows the simultaneous generation of attenuating mutations by gene deletions. The novel “knock-in” approach allows the rapid and efficient construction of recombinant Salmonella strains as vaccine carriers.

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Potera, Carol. "Phosphatase Makes Recombinant Salmonella Vaccine Vectors Safer." Microbe Magazine 6, no. 11 (January 1, 2011): 471–72. http://dx.doi.org/10.1128/microbe.6.471.1.

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Kang, Ho Young, Jay Srinivasan, and Roy Curtiss. "Immune Responses to Recombinant Pneumococcal PspA Antigen Delivered by Live Attenuated Salmonella enterica Serovar Typhimurium Vaccine." Infection and Immunity 70, no. 4 (April 2002): 1739–49. http://dx.doi.org/10.1128/iai.70.4.1739-1749.2002.

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ABSTRACT Attenuated Salmonella enterica serovar Typhimurium expressing recombinant antigens from other pathogens elicits primarily a Th1-type dominant immune response to both recombinant and Salmonella antigens. The immunogenicity and appropriate subcellular location of the recombinant antigen in the Salmonella vaccine strain may contribute to augmenting immune responses by facilitating adequate exposure of recombinant antigen to antigen-presenting cells for processing. To allow for secretion from gram-negative bacteria and overexpression of antigen, a DNA fragment encoding a highly antigenic α-helical region of PspA (pneumococcal surface protein A) was subcloned downstream from the β-lactamase signal sequence in the multicopy Asd+ pYA3493 vector to create pYA3494. pYA3493 was derived from a class of Asd+ vectors with reduced expression of Asd to minimize selective disadvantage and enhance immunization of expressed recombinant antigens. The S. enterica serovar Typhimurium vaccine strain was constructed by the introduction of deletion mutations Δcrp-28 and ΔasdA16. Approximately 50% of the recombinant PspA (rPspA) expressed in a Salmonella strain harboring pYA3494 was detected in the combined supernatant and periplasmic fractions of broth-grown recombinant Salmonella. After a single oral immunization in BALB/c mice with 109 CFU of the recombinant Salmonella vaccine strain carrying pYA3494, immunoglobulin G (IgG) antibody responses were stimulated to both the heterologous antigen rPspA and Salmonella lipopolysaccharide (LPS) and outer membrane proteins (OMPs). About half, and even more at later times after immunization, of the antibodies induced to rPspA were IgG1 (indicating a Th2-type response), whereas 60 to 70% of the antibodies to LPS and 80 to 90% of those to OMPs were IgG2a (indicating a Th1-type response). A sublethal infection with Streptococcus pneumoniae WU2 boosted PspA antibody levels and maintained IgG2a/IgG1 ratios similar to those seen before the challenge. Oral immunization with Salmonella-PspA vaccine protected 60% of immunized mice from death after intraperitoneal challenge with 50 times the 50% lethal dose of virulent S. pneumoniae WU2.

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Su, Huali, Qing Liu, Xiaoping Bian, Shifeng Wang, Roy Curtiss, and Qingke Kong. "Synthesis and delivery of Streptococcus pneumoniae capsular polysaccharides by recombinant attenuated Salmonella vaccines." Proceedings of the National Academy of Sciences 118, no. 2 (December 30, 2020): e2013350118. http://dx.doi.org/10.1073/pnas.2013350118.

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Streptococcus pneumoniae capsular polysaccharides (CPSs) are major determinants of bacterial pathogenicity. CPSs of different serotypes form the main components of the pneumococcal vaccines Pneumovax, Prevnar7, and Prevnar13, which substantially reduced the S. pneumoniae disease burden in developed countries. However, the laborious production processes of traditional polysaccharide-based vaccines have raised the cost of the vaccines and limited their impact in developing countries. The aim of this study is to develop a kind of low-cost live vaccine based on using the recombinant attenuated Salmonella vaccine (RASV) system to protect against pneumococcal infections. We cloned genes for seven different serotypes of CPSs to be expressed by the RASV strain. Oral immunization of mice with the RASV-CPS strains elicited robust Th1 biased adaptive immune responses. All the CPS-specific antisera mediated opsonophagocytic killing of the corresponding serotype of S. pneumoniae in vitro. The RASV-CPS2 and RASV-CPS3 strains provided efficient protection of mice against challenge infections with either S. pneumoniae strain D39 or WU2. Synthesis and delivery of S. pneumoniae CPSs using the RASV strains provide an innovative strategy for low-cost pneumococcal vaccine development, production, and use.

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Gunn, Bronwyn M., Soo-Young Wanda, Dana Burshell, Caihong Wang, and Roy Curtiss. "Construction of Recombinant Attenuated Salmonella enterica Serovar Typhimurium Vaccine Vector Strains for Safety in Newborn and Infant Mice." Clinical and Vaccine Immunology 17, no. 3 (March 2010): 354–62. http://dx.doi.org/10.1128/cvi.00412-09.

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ABSTRACT Recombinant bacterial vaccines must be safe, efficacious, and well tolerated, especially when administered to newborns and infants to prevent diseases of early childhood. Many means of attenuation have been shown to render vaccine strains susceptible to host defenses or unable to colonize lymphoid tissue effectively, thus decreasing their immunogenicity. We have constructed recombinant attenuated Salmonella vaccine strains that display high levels of attenuation while retaining the ability to induce high levels of immunogenicity and are well tolerated in high doses when administered to infant mice as young as 24 h old. The strains contain three means of regulated delayed attenuation, as well as a constellation of additional mutations that aid in enhancing safety, regulate antigen expression, and reduce disease symptoms commonly associated with Salmonella infection. The vaccine strains are well tolerated when orally administered to infant mice 24 h old at doses as high as 3.5 × 108 CFU.

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Cao, Y., Z. Wen, and D. Lu. "Construction of a recombinant oral vaccine against Salmonella typhi and Salmonella typhimurium." Infection and Immunity 60, no. 7 (1992): 2823–27. http://dx.doi.org/10.1128/iai.60.7.2823-2827.1992.

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Curtiss III, Roy, Wei Xin, Yuhua Li, Wei Kong, Soo-Young Wanda, Bronwyn Gunn, and Shifeng Wang. "New Technologies in Using Recombinant Attenuated Salmonella Vaccine Vectors." Critical Reviews™ in Immunology 30, no. 3 (2010): 255–70. http://dx.doi.org/10.1615/critrevimmunol.v30.i3.30.

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Wang, Shifeng, Qingke Kong, and Roy Curtiss. "New technologies in developing recombinant attenuated Salmonella vaccine vectors." Microbial Pathogenesis 58 (May 2013): 17–28. http://dx.doi.org/10.1016/j.micpath.2012.10.006.

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Xu, Xin, Mohamed I. Husseiny, Andreas Goldwich, and Michael Hensel. "Efficacy of Intracellular Activated Promoters for Generation of Salmonella-Based Vaccines." Infection and Immunity 78, no. 11 (August 23, 2010): 4828–38. http://dx.doi.org/10.1128/iai.00298-10.

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ABSTRACT Salmonella enterica is a versatile vaccine carrier for heterologous antigens. One strategy for vaccine antigen delivery is the use of live attenuated S. enterica strains that translocate heterologous antigens into antigen-presenting cells by means of type III secretion systems (T3SS). The feasibility of this approach has been demonstrated in various experimental vaccination studies. The efficacy of recombinant live vaccines is critically influenced by the optimal level of attenuation and many other factors. For the rational design of approaches involving translocation by T3SS, additional parameters are the level of expression of the heterologous antigens and the selection of carrier proteins for the delivery of antigens to desirable subcellular compartments of the target cell. We deployed the Salmonella pathogenicity island 2 (SPI2)-encoded T3SS for antigen delivery. The SPI2-T3SS and effector proteins are encoded by members of the large SsrAB regulon, including promoters with highly variable strength of expression. We investigated the effect of various in vivo-activated promoters of the SsrAB regulon on the efficacy of recombinant Salmonella vaccines. We observed that the use of promoters with higher strength results in greater synthesis of recombinant antigens and greater stimulation of T-cell responses in cell culture assays for the stimulation of T cells by the model antigen ovalbumin. In contrast, in vaccination experiments, promoters with a low level of expression resulted in the induction of higher amounts of T cells reactive to the model antigen listeriolysin. These results demonstrate that high-level expression of heterologous antigens does not necessarily result in optimal stimulation of immune responses.

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Benitez, Alvaro J., Nina McNair, and Jan R. Mead. "Oral Immunization with Attenuated Salmonella enterica Serovar Typhimurium Encoding Cryptosporidium parvum Cp23 and Cp40 Antigens Induces a Specific Immune Response in Mice." Clinical and Vaccine Immunology 16, no. 9 (July 15, 2009): 1272–78. http://dx.doi.org/10.1128/cvi.00089-09.

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ABSTRACT Attenuated Salmonella enterica serovar Typhimurium vaccine strain SL3261 was used as an antigen delivery system for the oral immunization of mice against two Cryptosporidium parvum antigens, Cp23 and Cp40. Each antigen was subcloned into the pTECH1 vector system, which allows them to be expressed as fusion proteins with highly immunogenic fragment C of tetanus toxin under the control of the anaerobically inducible nirB promoter. The recombinant vector was introduced into Salmonella Typhimurium vaccine strain SL3261, and the stable soluble expression of the chimeric protein was evaluated and confirmed by Western blotting with polyclonal C. parvum antisera. Mice were inoculated orally with a single dose of SL3261/pTECH-Cp23 or Cp40, respectively, and plasmid stability was demonstrated both in vitro and in vivo. Specific serum immunoglobulin G (IgG) antibodies against the Cp23 or Cp40 antigen were detected by enzyme-linked immunosorbent assay 35 days after immunization. Also, serum IgA and mucosal (feces) IgA antibodies were detected in 30% of the mice immunized with Cp23. In addition, prime-boosting with Cp23 and Cp40 DNA vaccine vectors followed by Salmonella immunization significantly increased antibody responses to both antigens. Our data show that a single oral inoculation with recombinant S. Typhimurium SL3261 can induce specific antibody responses to the Cp23 or Cp40 antigen from C. parvum in mice, suggesting that recombinant Salmonella is a feasible delivery system for a vaccine against C. parvum infection.

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Kang, Xilong, Yun Yang, Yang Jiao, Hongqin Song, Li Song, Dan Xiong, Lili Wu, Zhiming Pan, and Xinan Jiao. "HA1-2-fljB Vaccine Induces Immune Responses against Pandemic Swine-Origin H1N1 Influenza Virus in Mice." Journal of Molecular Microbiology and Biotechnology 26, no. 6 (2016): 422–32. http://dx.doi.org/10.1159/000448895.

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In 2009, a novel pandemic swine-origin influenza A (H1N1) virus caused a public emergency of international concern. Vaccination is the primary strategy for the control of influenza epidemics. However, the poor immunopotency of many vaccine antigens is a major barrier to the development of effective vaccines against influenza. Flagellin, a Toll-like receptor 5 (TLR5) ligand, has been used as an adjuvant to enhance the immunopotency of vaccines in preclinical studies. Here, we developed a recombinant candidate vaccine, HA1-2-fljB, in which the globular head of the hemagglutinin (HA) antigen (residues 62-284) from H1N1 virus was fused genetically to the N-terminus of <i>Salmonella typhimurium</i> ﬂjB. The recombinant HA1-2-fljB protein was expressed efficiently in<i> Escherichia coli</i>, and the immunogenicity and protective efficacy of recombinant HA1-2-fljB were evaluated in a mouse model. Immunization with HA1-2-fljB elicited robust IgG antibodies and neutralizing antibodies and completely protected the mice against infection by swine-origin influenza A/swine/Jangsu/38/2010 (H1N1). These results suggest that HA antigen placed at the N-terminus of flagellin is also an excellent starting point for creating a fusion HA1-2-fljB protein as a candidate vaccine, and the recombinant HA1-2-fljB protein will contribute to the development of a more effective vaccine against swine-origin influenza virus infection.

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Baud, David, Jalil Benyacoub, Véronique Revaz, Menno Kok, Françoise Ponci, Martine Bobst, Roy Curtiss, Pierre De Grandi, and Denise Nardelli-Haefliger. "Immunogenicity against Human Papillomavirus Type 16 Virus-Like Particles Is Strongly Enhanced by the PhoPc Phenotype in Salmonella enterica Serovar Typhimurium." Infection and Immunity 72, no. 2 (February 2004): 750–56. http://dx.doi.org/10.1128/iai.72.2.750-756.2004.

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ABSTRACT Recombinant Salmonella strains have been widely used to deliver heterologous antigens and induce immune responses in vaccinated animals and humans. It remains to be established, however, how these bacteria mount an immune response; this has prevented the rational design of vaccines. Here we report for the first time that a particular genetic program, PhoPc, is necessary for recombinant Salmonella strains to induce an antibody response to a heterologous antigen, the human papillomaviruses type 16 (HPV16) virus-like particle (VLP). The PhoPc phenotype results from a point mutation in phoQ, the gene encoding the sensor component of a two-component regulatory system (PhoP-PhoQ) that controls the expression of a number of virulence factors in Salmonellae. To demonstrate that immunogenicity of the viral antigen expressed by the bacterial vector was dependent on the PhoPc phenotype, we have expressed the phoQ mutant gene (phoQ24) in two differently attenuated Salmonella enterica serovar Typhimurium strains. Our data show extrachromosomal phoQ24 to be dominant over the chromosomal copy of the phoQ gene, conferring the PhoPc phenotype on the recipient strains. In addition, activation of PhoPQ-regulated genes by the plasmid-encoded PhoQ24 did not alter bacterial survival and conferred immunogenicity to the HPV16 VLP expressed in the two S. enterica serovar Typhimurium backgrounds, inducing the production of HPV-specific antibodies in mice. This strongly suggests that at least one of the PhoP-regulated genes is necessary for mounting an efficient antibody response to HPV16 VLP. This finding sets the stage for further development of a Salmonella-based vaccine against HPV infection and cervical cancer.

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Guillobel, Heloisa C. R., Joana I. Carinhanha, Lucia Cárdenas, John D. Clements, Darcy F. de Almeida, and Luís C. S. Ferreira. "Adjuvant Activity of a Nontoxic Mutant of Escherichia coli Heat-Labile Enterotoxin on Systemic and Mucosal Immune Responses Elicited against a Heterologous Antigen Carried by a LiveSalmonella enterica Serovar Typhimurium Vaccine Strain." Infection and Immunity 68, no. 7 (July 1, 2000): 4349–53. http://dx.doi.org/10.1128/iai.68.7.4349-4353.2000.

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ABSTRACT Systemic and mucosal antibody responses against both the major subunit of colonization factor antigen I (CFA/I) of enterotoxigenicEscherichia coli (ETEC) and the somatic lipopolysaccharide expressed by recombinant bivalent Salmonella vaccine strains were significantly enhanced by coadministration of a detoxified derivative with preserved adjuvant effects of the ETEC heat-labile toxin, LT(R192G). The results further support the adjuvant effects of LT(R192G) and represent a simple alternative to improve responses against passenger antigens expressed by orally delivered Salmonella vaccine strains.

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Luo, Fengling, Yong Feng, Min Liu, Pingfei Li, Qin Pan, Victor Tunje Jeza, Bing Xia, Jianguo Wu, and Xiao-Lian Zhang. "Type IVB Pilus Operon Promoter Controlling Expression of the Severe Acute Respiratory Syndrome-Associated Coronavirus Nucleocapsid Gene in Salmonella enterica Serovar Typhi Elicits Full Immune Response by Intranasal Vaccination." Clinical and Vaccine Immunology 14, no. 8 (June 27, 2007): 990–97. http://dx.doi.org/10.1128/cvi.00076-07.

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ABSTRACT Attenuated Salmonella enterica serovar Typhi strains have been considered to be attractive as potential live oral delivery vector vaccines because of their ability to elicit the full array of immune responses in humans. In this study, we constructed an attenuated S. enterica serovar Typhi strain stably expressing conserved nucleocapsid (N) protein of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) by integrating the N gene into the pilV gene, which was under the control of the type IVB pilus operon promoter in S. enterica serovar Typhi. BALB/c mice were immunized with this recombinant strain through different routes: intranasally, orogastrically, intraperitoneally, and intravenously. Results showed that the intranasal route caused the highest production of specific immunoglobulin G (IgG), IgG2a, and secretory IgA, where IgG2a was imprinted as a Th1 cell bias. Moreover, this recombinant live vaccine induced significantly high levels of specific cytotoxic T-lymphocyte activities and increased gamma interferon-producing T cells compared with the parental strain. Our work provides insights into how the type IVB pilus operon promoter controlling SARS-CoV N gene expression in Salmonella might be attractive for a live-vector vaccine against SRAS-CoV infection, for it could induce mucosal, humoral, and cellular immune responses. Our work also indicates that the type IVB pilus operon promoter controlling foreign gene expression in Salmonella can elicit full immune responses by intranasal vaccination.

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Kohler, James J., Latha Pathangey, Adnan Hasona, Ann Progulske-Fox, and Thomas A. Brown. "Long-Term Immunological Memory Induced by Recombinant Oral Salmonella Vaccine Vectors." Infection and Immunity 68, no. 7 (July 1, 2000): 4370–73. http://dx.doi.org/10.1128/iai.68.7.4370-4373.2000.

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ABSTRACT We have previously shown that Salmonella entericaserovar Typhimurium expressing the hagB hemagglutinin gene from Porphyromonas gingivalis can induce primary and recall immune responses in serum and secretions in mice; however, the longevity of memory induced by oral Salmonella carriers has not been adequately demonstrated. In this study, we examined the capacity of mice to mount a recall response 52 weeks after primary immunization. Recall responses were seen in serum immunoglobulin G (IgG) and IgA following boosting at week 52, and in most cases, they were equal to or greater than the primary responses. Significant mucosal IgA recall responses in saliva and vaginal wash were also detected following boosting at week 52. In addition, there was a considerable residual response in secretions at week 51, prior to boosting. These results indicate that oral Salmonellavectors can induce long-term memory to recombinant HagB and are particularly effective at inducing long-lasting mucosal responses as well as at inducing the capacity for mucosal recall responses.

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Sbrogio-Almeida, M. E., T. Mosca, L. M. Massis, I. A. Abrahamsohn, and L. C. S. Ferreira. "Host and Bacterial Factors Affecting Induction of Immune Responses to Flagellin Expressed by Attenuated Salmonella Vaccine Strains." Infection and Immunity 72, no. 5 (May 2004): 2546–55. http://dx.doi.org/10.1128/iai.72.5.2546-2555.2004.

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ABSTRACT Previous observations demonstrated that the delivery of recombinant Salmonella enterica serovar Dublin strains to mice via mucosal routes did not efficiently activate systemic and secreted antibody responses to either type d flagellin or genetically fused heterologous B-cell epitopes, thus reducing the usefulness of the protein as a carrier of epitopes for vaccine purposes. In this work, we investigated murine systemic and mucosal flagellin immunogenicity after oral immunization with attenuated Salmonella strains. The reduced anti-type d flagellin antibody responses in mice immunized via mucosal routes with three doses of flagellated S. enterica serovar Dublin strains were not caused by oral tolerance and could not be restored by coadministration of a mucosal adjuvant. The induction of antibody responses to Salmonella flagellins was shown to differ according to the genetic background, but not the haplotype, of the mouse lineage. Moreover, BALB/c mice orally immunized with S. enterica serovar Typhimurium strains developed anti-type i flagellin sera and secreted antibody responses, which indicated that the serovar of the Salmonella vaccine strain also affected flagellin immunogenicity. Analyses of cytokine responses of BALB/c mice immunized with three oral doses of flagellated S. enterica serovar Dublin vaccine strains showed that, in spite of the lack of antibody responses, elevated type d flagellin-specific CD4-cell-activation-dependent gamma interferon (IFN-γ) and interleukin-10 responses were elicited after the administration of the vaccine strains via either parenteral or mucosal routes. Similar cytokine production patterns were detected to a T-cell heterologous epitope, derived from the CFA/I fimbriae of enterotoxigenic Escherichia coli (ETEC), in mice orally immunized with a Salmonella vaccine strain expressing hybrid flagella. These results indicate that the immunogenicities of Salmonella flagellins can differ significantly, depending on the murine host and on the bacterial vector used, and demonstrate that the induction of CD4-cell-activation-dependent IFN-γ production represents a major immune response triggered by flagellin and in-frame fused heterologous T-cell epitopes after the oral administration of recombinant S. enterica serovar Dublin vaccine strains.

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Schnapp, Anita R., Chris S. Eickhoff, Donata Sizemore, Roy Curtiss, and Daniel F. Hoft. "Cruzipain Induces Both Mucosal and Systemic Protection against Trypanosoma cruzi in Mice." Infection and Immunity 70, no. 9 (September 2002): 5065–74. http://dx.doi.org/10.1128/iai.70.9.5065-5074.2002.

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ABSTRACT Cruzipain, the major cysteinyl proteinase of Trypanosoma cruzi, is expressed by all developmental forms and strains of the parasite and stimulates potent humoral and cellular immune responses during infection in both humans and mice. This information suggested that cruzipain could be used to develop an effective T. cruzi vaccine. To study whether cruzipain-specific T cells could inhibit T. cruzi intracellular replication, we generated cruzipain-reactive CD4+ Th1 cell lines. These T cells produced large amounts of gamma interferon when cocultured with infected macrophages, resulting in NO production and decreased intracellular parasite replication. To study the protective effects in vivo of cruzipain-specific Th1 responses against systemic T. cruzi challenges, we immunized mice with recombinant cruzipain plus interleukin 12 (IL-12) and a neutralizing anti-IL-4 MAb. These immunized mice developed potent cruzipain-specific memory Th1 cell responses and were significantly protected against normally lethal systemic T. cruzi challenges. Although cruzipain-specific Th1 responses were associated with T. cruzi protective immunity in vitro and in vivo, adoptive transfer of cruzipain-specific Th1 cells alone did not protect BALB/c histocompatible mice, indicating that additional immune mechanisms are important for cruzipain-specific immunity. To study whether cruzipain could induce mucosal immune responses relevant for vaccine development, we prepared recombinant attenuated Salmonella enterica serovar Typhimurium vaccines expressing cruzipain. BALB/c mice immunized with salmonella expressing cruzipain were significantly protected against T. cruzi mucosal infection. Overall, these data indicate that cruzipain is an important T. cruzi vaccine candidate and that protective T. cruzi vaccines will need to induce more than CD4+ Th1 cells alone.

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Baud, David, Françoise Ponci, Martine Bobst, Pierre De Grandi, and Denise Nardelli-Haefliger. "Improved Efficiency of a Salmonella-Based Vaccine against Human Papillomavirus Type 16 Virus-Like Particles Achieved by Using a Codon-Optimized Version of L1." Journal of Virology 78, no. 23 (December 1, 2004): 12901–9. http://dx.doi.org/10.1128/jvi.78.23.12901-12909.2004.

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ABSTRACT Cervical cancer results from cervical infection by human papillomaviruses (HPVs), especially HPV16. An effective vaccine against these HPVs is expected to have a dramatic impact on the incidence of this cancer and its precursor lesions. The leading candidate, a subunit prophylactic HPV virus-like particle (VLP) vaccine, can protect women from HPV infection. An alternative improved vaccine that avoids parenteral injection, that is efficient with a single dose, and that induces mucosal immunity might greatly facilitate vaccine implementation in different settings. In this study, we have constructed a new generation of recombinant Salmonella organisms that assemble HPV16 VLPs and induce high titers of neutralizing antibodies in mice after a single nasal or oral immunization with live bacteria. This was achieved through the expression of a HPV16 L1 capsid gene whose codon usage was optimized to fit with the most frequently used codons in Salmonella. Interestingly, the high immunogenicity of the new recombinant bacteria did not correlate with an increased expression of L1 VLPs but with a greater stability of the L1-expressing plasmid in vitro and in vivo in absence of antibiotic selection. Anti-HPV16 humoral and neutralizing responses were also observed with different Salmonella enterica serovar Typhimurium strains whose attenuating deletions have already been shown to be safe after oral vaccination of humans. Thus, our findings are a promising improvement toward a vaccine strain that could be tested in human volunteers.

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Leal, Monica Teixeira Andrade, Ariane Guglielmi Ariza Camacho, Laís Helena Teixeira, Daniel Youssef Bargieri, Irene Silva Soares, Cibele Aparecida Tararam, and Mauricio M. Rodrigues. "Immunogenicity of Recombinant Proteins Consisting of Plasmodium vivax Circumsporozoite Protein Allelic Variant-Derived Epitopes Fused with Salmonella enterica Serovar Typhimurium Flagellin." Clinical and Vaccine Immunology 20, no. 9 (July 17, 2013): 1418–25. http://dx.doi.org/10.1128/cvi.00312-13.

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ABSTRACTAPlasmodium falciparumcircumsporozoite protein (CSP)-based recombinant fusion vaccine is the first malaria vaccine to reach phase III clinical trials. Resistance to infection correlated with the production of antibodies to the immunodominant central repeat region of the CSP. In contrast toP. falciparum, vaccine development against the CSP ofPlasmodium vivaxmalaria is far behind. Based on this gap in our knowledge, we generated a recombinant chimeric protein containing the immunodominant central repeat regions of theP. vivaxCSP fused toSalmonella entericaserovar Typhimurium-derived flagellin (FliC) to activate the innate immune system. The recombinant proteins that were generated contained repeat regions derived from each of the 3 different allelic variants of theP. vivaxCSP or a fusion of regions derived from each of the 3 allelic forms. Mice were subcutaneously immunized with the fusion proteins alone or in combination with the Toll-like receptor 3 (TLR-3) agonist poly(I·C), and the anti-CSP serum IgG response was measured. Immunization with a mixture of the 3 recombinant proteins, each containing immunodominant epitopes derived from a single allelic variant, rather than a single recombinant protein carrying a fusion of regions derived from each of 3 allelic forms elicited a stronger immune response. This response was independent of TLR-4 but required TLR-5/MyD88 activation. Antibody titers significantly increased when poly(I·C) was used as an adjuvant with a mixture of the 3 recombinant proteins. These recombinant fusion proteins are novel candidates for the development of an effective malaria vaccine againstP. vivax.

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Popova, P. Yu, and N. I. Mikshis. "PERSPECTIVES OF DEVELOPMENT OF LIVE RECOMBINANT ANTHRAX VACCINES BASED ON OPPORTUNISTIC AND APATHOGENIC MICROORGANISMS." Journal of microbiology epidemiology immunobiology, no. 1 (February 28, 2016): 79–89. http://dx.doi.org/10.36233/0372-9311-2016-1-79-89.

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Live genetic engineering anthrax vaccines on the platform of avirulent and probiotic micro-ogranisms are a safe and adequate alternative to preparations based on attenuated Bacillus anthracis strains. Mucosal application results in a direct contact of the vaccine preparations with mucous membranes in those organs and tissues of the macro-organisms, that are exposed to the pathogen in the first place, resulting in a development of local and systemic immune response. Live recombinant anthrax vaccines could be used both separately as well as in a prime-boost immunization scheme. The review focuses on immunogenic and protective properties of experimental live genetic engineering preparations, created based on members ofgeni of Salmonella, Lactobacillus and adenoviruses.

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Nurjayadi, Muktiningsih, Izzatul Ilma Chairinnisa, Geta Putri Mentari, Dudi Hardianto, Asri Sulfianti, and Kurnia Agustini. "Pengaruh Jumlah Inokulum Sel Inang Bakteri E.coli BL21 (DE3) pLysS dan Waktu Overekspresi pada Produksi Protein Rekombinan Fim-C Salmonella typhi." Jurnal Kimia VALENSI 4, no. 2 (November 30, 2018): 98–106. http://dx.doi.org/10.15408/jkv.v4i2.8077.

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Recombinant protein Fim-C S.typhi is a potential protein that can be used as an alternative typhoid vaccine and produced on a large scale. However, before entering into a large-scale stage, laboratory optimum data on the factors that affect the production process of Fim-C Salmonella typhi proteins are required. This study aims to obtain information regarding the effect of host cell number E.coli BL21 (DE3) pLysS and overexpression time on production of recombinant protein Fim-C Salmonella typhi as the basis for developing candidate of typhoid vaccine. The optimization process of overexpression was done by adding 0.5 mM IPTG (Isopropyl-β-D-thiogalactopyranoside) inducer into bacterial cultures of 2%, 4%, and 6% with 4, 5, and 6 hours over expression. The measurement of the concentration of Fim-C recombinant protein extracted samples were done by a spectrophotometric method used BCA Kit Assay Thermo ScientificTM with wavelength 590nm. The characterization of those protein extracts was performed using SDS-PAGE method. The results from the study concluded that the number of 4% E.coli bacterial cells and four-hour overexpression time are the optimum condition of Fim- C Salmonella typhi characterized by the presence of high-intensity bands at ± 31 kDa.

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Vindurampulle, Christofer J., and Stephen R. Attridge. "Impact of Vector Priming on the Immunogenicity of Recombinant Salmonella Vaccines." Infection and Immunity 71, no. 1 (January 2003): 287–97. http://dx.doi.org/10.1128/iai.71.1.287-297.2003.

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ABSTRACT There are conflicting reports concerning the impact of prior vector priming on the immunogenicity of recombinant-Salmonella-based vaccines. A comparison of experimental protocols identified two variables which might account for this inconsistency: the potential of the vector strain to colonize the murine gut-associated lymphoid tissue (GALT) and the nature of the foreign antigen subsequently delivered by the recombinant Salmonella construct. The former was investigated by constructing an aroA mutant of the Salmonella enterica serovar Stanley vector previously used in our laboratory. Although the introduction of an aroA mutation had surprisingly little effect on GALT colonization, it did reduce the strength of antilipopolysaccharide (anti-LPS) antibody responses and the impact of vector priming. Studies were also performed to ascertain the extent to which any observed hyporesponsiveness consequent upon vector priming might be determined by the characteristics of the foreign antigen. S. enterica serovar Stanley was used to deliver either of two Escherichia coli antigens, K88 pilus protein or the LT-B toxin subunit, to vector-primed mice. Both serum immunoglobulin G (IgG) and intestinal IgA responses to K88 were completely abolished, and those to LT-B were significantly reduced, as a consequence of vector priming. When similar experiments were performed with an aroA S. enterica serovar Dublin vector, responses to K88 were significantly reduced but those to LT-B were unaffected by vector priming. Paradoxically, a priming infection with this vector induced stronger anti-LPS antibody responses but was less likely to elicit a state of hyporesponsiveness to subsequently presented foreign antigen. The impact of vector priming thus depends on both the Salmonella strain used and the nature of the foreign antigen, but our present data strengthen concerns that preexisting antivector immunity represents a serious threat to the Salmonella-based vaccine strategy.

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Kozarov, Emil, Naohisa Miyashita, Jacob Burks, Karen Cerveny, Thomas A. Brown, William P. McArthur, and Ann Progulske-Fox. "Expression and Immunogenicity of Hemagglutinin A from Porphyromonas gingivalis in an AvirulentSalmonella enterica Serovar Typhimurium Vaccine Strain." Infection and Immunity 68, no. 2 (February 1, 2000): 732–39. http://dx.doi.org/10.1128/iai.68.2.732-739.2000.

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ABSTRACT Porphyromonas gingivalis is a major etiologic agent of periodontitis, a chronic inflammatory disease that ultimately results in the loss of the supporting tissues of the teeth. Previous work has demonstrated the usefulness of avirulent Salmonella enterica serovar Typhimurium strains as antigen delivery systems for protective antigens of pathogens that colonize or cross mucosal surfaces. In this study, we constructed and characterized a recombinantS. enterica serovar Typhimurium avirulent vaccine strain which expresses hemagglutinin A and carries no antibiotic resistance markers. HagA, a major virulence-associated surface protein, is a potentially useful immunogen that contains an antigenic epitope which, in humans, elicits an immune response that is protective against subsequent colonization by P. gingivalis. ThehagA gene, including its promoter, was cloned into a balanced-lethal Salmonella vector and transferred to the vaccine strain. Heterologous expression of HagA was demonstrated in both Escherichia coli JM109 and S. entericaserovar Typhimurium vaccine strain χ4072. The HagA epitope was present in its native configuration as determined by immunochemistry and immunoelectron microscopy. Purified recombinant HagA was recognized by sera from mice immunized with the S. enterica serovar Typhimurium vaccine strain. The HagA-specific antigen of the vaccine was also found to be recognized by serum from a periodontal patient. This vaccine strain, which expresses the functional hemagglutinin protein, induces a humoral immune response against HagA and may be useful for developing a protective vaccine against periodontal diseases associated with P. gingivalis.

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Torres-Escobar, Ascención, María Dolores Juárez-Rodríguez, Bronwyn M. Gunn, Christine G. Branger, Steven A. Tinge, and Roy Curtiss. "Fine-Tuning Synthesis of Yersinia pestis LcrV from Runaway-Like Replication Balanced-Lethal Plasmid in a Salmonella enterica Serovar Typhimurium Vaccine Induces Protection against a Lethal Y. pestis Challenge in Mice." Infection and Immunity 78, no. 6 (March 22, 2010): 2529–43. http://dx.doi.org/10.1128/iai.00005-10.

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ABSTRACT A balanced-lethal plasmid expression system that switches from low-copy-number to runaway-like high-copy-number replication (pYA4534) was constructed for the regulated delayed in vivo synthesis of heterologous antigens by vaccine strains. This is an antibiotic resistance-free maintenance system containing the asdA gene (essential for peptidoglycan synthesis) as a selectable marker to complement the lethal chromosomal ΔasdA allele in live recombinant attenuated Salmonella vaccines (RASVs) such as Salmonella enterica serovar Typhimurium strain χ9447. pYA4534 harbors two origins of replication, pSC101 and pUC (low and high copy numbers, respectively). The pUC replication origin is controlled by a genetic switch formed by the operator/promoter of the P22 cro gene (O/Pcro) (PR), which is negatively regulated by an arabinose-inducible P22 c2 gene located on both the plasmid and the chromosome (araC PBAD c2). The absence of arabinose, which is unavailable in vivo, triggers replication to a high-copy-number plasmid state. To validate these vector attributes, the Yersinia pestis virulence antigen LcrV was used to develop a vaccine against plague. An lcrV sequence encoding amino acids 131 to 326 (LcrV196) was optimized for expression in Salmonella, flanked with nucleotide sequences encoding the signal peptide (SS) and the carboxy-terminal domain (CT) of β-lactamase, and cloned into pYA4534 under the control of the Ptrc promoter to generate plasmid pYA4535. Our results indicate that the live Salmonella vaccine strain χ9447 harboring pYA4535 efficiently stimulated a mixed Th1/Th2 immune response that protected mice against lethal challenge with Y. pestis strain CO92 introduced through either the intranasal or subcutaneous route.

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Benyacoub, Jalil, Sally Hopkins, Alexandra Potts, Sandra Kelly, Jean-Pierre Kraehenbuhl, Roy Curtiss, Pierre De Grandi, and Denise Nardelli-Haefliger. "The Nature of the Attenuation of Salmonella typhimurium Strains Expressing Human Papillomavirus Type 16 Virus-Like Particles Determines the Systemic and Mucosal Antibody Responses in Nasally Immunized Mice." Infection and Immunity 67, no. 7 (July 1, 1999): 3674–79. http://dx.doi.org/10.1128/iai.67.7.3674-3679.1999.

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ABSTRACT We have recently shown by using a recombinant Salmonella typhimurium PhoPc strain in mice the feasibility of using a Salmonella-based vaccine to prevent infection by the genital human papillomavirus type 16 (HPV16). Here, we compare the HPV16-specific antibody responses elicited by nasal immunization with recombinant S. typhimurium strains harboring attenuations that, in contrast to PhoPc, are suitable for human use. For this purpose, χ4989 (Δcya Δcrp) and χ4990 [Δcya Δ(crp-cdt)] were constructed in the ATCC 14028 genetic background, and comparison was made with the isogenic PhoPc and PhoP− strains. Although the levels of expression of HPV16 virus-like particle (VLP) were similar in all strains, only PhoPc HPV16 induced sustained specific antibody responses after nasal immunization, while all strains induced high antibody responses with a single nasal immunization when an unrelated viral hepatitis B core antigen was expressed. The level of the specific antibody responses induced did not correlate with the number of recombinant bacteria surviving in various organs 2 weeks after immunization. Our data suggest that the immunogenicity of attenuated Salmonella vaccine strains does not correlate with either the number of persisting bacteria after immunization or the levels of in vitro expression of the antigen carried. Rather, the PhoPc phenotype appears to provide the unique ability inSalmonella to induce immune responses against HPV16 VLPs.

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Bidmeshki Barzoki, Tahereh, Ali Mohammad Ahadi, and Hoda Ayat. "A New Design and Epitopes Analysis for Recombinant Vaccine against Salmonella typhi by In silico Analysis." Trends in Immunotherapy 4, no. 2 (August 24, 2020): 1. http://dx.doi.org/10.24294/ti.v4.i2.891.

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Nowadays, foodborne diseases are one of the main problems of the world that infect humans due to consumption of contaminated water or food. Typhoid fever is one of the major causes of illness and death in the world caused by Salmonella typhi. Vaccination is one of the most effective approaches in order to reduction of the disease risk. The main goal of this study is designing and characterization of antigenic determinants of a fusion protein originated from S.typhi usable as an effective vaccine. In this study, the outer membrane proteins of salmonella have been considered as candidates conferring protection against typhoid. Considering the evidence, OmpA, OmpF and OmpC proteins of salmonella applied in a multivalent vaccine design. Conserved motives of these proteins were selected using the CLC software and then their extracellular regions of these peptides were identified with PRED-TMBB server. Appropriate motives were combined for design of final fusion protein. Finally epitops of designed protein with high antigenic properties were identified using BCPREDS, Ellipro, ABCpred, EpiJen, NetCTL-1.2, CTLpred, TAPpred, ProPred and VaxiJen servers. Predicted designed protein in this study reached a very high scores for antigenic indexes. Encoding Genetic construction of this fusion protein could be applied for production of the recombinant OmpA.OmpF.OmpC derived fusion protein with effective antigenic properties as a new vaccine against S.typhi. Laboratory experiments and animal challenging analyses is ongoing.

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Hui, F. M., C. L. Meng, N. N. Guo, L. G. Yang, F. X. Shi, and D. G. Mao. "Evaluation of attenuated Salmonella choleraesuis-mediated inhibin recombinant DNA vaccine in rats." Genetics and Molecular Research 13, no. 3 (2014): 6113–25. http://dx.doi.org/10.4238/2014.august.7.27.

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Rizos, Konstantin, Claus T. Lattemann, Dirk Bumann, Thomas F. Meyer, and Toni Aebischer. "Autodisplay." Infection and Immunity 71, no. 11 (November 2003): 6320–28. http://dx.doi.org/10.1128/iai.71.11.6320-6328.2003.

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ABSTRACT Live attenuated Salmonella strains expressing antigens of pathogens are promising oral vaccine candidates. There is growing evidence that the topology of expression of the foreign antigens can have a dramatic impact on the immunogenicity. We examined the potential of the AIDA-I (Escherichia coli adhesin involved in diffuse adherence) autotransporter domain to display antigenic fragments of the urease A subunit of Helicobacter pylori for the induction of a protective immune response. In the murine H. pylori model, protection is mainly mediated by CD4+ T cells, and we therefore used the AIDA-I expression system to successfully express both nearly full-length UreA and defined T-helper-cell epitopes on the surface of an attenuated Salmonella enterica serovar Typhimurium vaccine strain. Surface exposure of the large UreA fragment or of one UreA T-cell epitope mediated a significant reduction in the level of H. pylori in immunized mice after challenge infection, whereas conventional cytoplasmic expression of UreA in Salmonella had no effect. These results support the concept that surface display increases the immunogenicity of recombinant antigens expressed on oral live vaccine carriers and further demonstrate the feasibility of immunizing against H. pylori with Salmonella vaccine strains expressing CD4+ T-cell epitopes.

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Kohler, James J., Latha B. Pathangey, Sheila R. Gillespie, and Thomas A. Brown. "Effect of Preexisting Immunity to Salmonella on the Immune Response to Recombinant Salmonella enterica Serovar Typhimurium Expressing a Porphyromonas gingivalisHemagglutinin." Infection and Immunity 68, no. 6 (June 1, 2000): 3116–20. http://dx.doi.org/10.1128/iai.68.6.3116-3120.2000.

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ABSTRACT Recombinant Salmonella strains expressing foreign heterologous genes have been extensively studied as live oral vaccine delivery vectors. We have investigated the mucosal and systemic immune responses following oral immunization with a recombinantSalmonella enterica serovar Typhimurium expressing the hemagglutinin HagB from Porphyromonas gingivalis, a suspected etiological agent of adult periodontal disease. We have previously shown a primary mucosal and systemic response following oral immunization with χ4072/pDMD1 and recall responses following boosting at 14 weeks after primary immunization. In this study, we examined the effects of earlier boosting as well as the effects of deliberately induced immunity to the Salmonella carrier strain on subsequent immune responses. Mice boosted at week 7 following immunization, a point which corresponded to the peak of the primary response, generally showed lower responses than those boosted at week 14. When mice were preimmunized with the Salmonella carrier alone and then immunized with the recombinant strain 7 or 14 weeks later, significant reductions were seen for serum immunoglobulin G (IgG) antibodies at week 14 and for salivary IgA at week 7. No reductions were seen in serum IgA or vaginal wash IgA antibodies. Mice appear to be refractory to boosting with orally administered salmonellae at 7 weeks. Deliberate immunization with the carrier strain did not appreciably affect recall responses at 14 weeks, with the exception of the serum IgG responses, nor did it affect colonization of the Peyer's patches.

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Kulkarni, R. R., V. R. Parreira, Y. F. Jiang, and J. F. Prescott. "A Live Oral Recombinant Salmonella enterica Serovar Typhimurium Vaccine Expressing Clostridium perfringens Antigens Confers Protection against Necrotic Enteritis in Broiler Chickens." Clinical and Vaccine Immunology 17, no. 2 (December 9, 2009): 205–14. http://dx.doi.org/10.1128/cvi.00406-09.

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ABSTRACT Necrotic enteritis (NE) in broiler chickens is caused by Clostridium perfringens, and there is currently no effective vaccine for NE. We previously showed that in broiler chickens protection against NE can be achieved through intramuscular immunization with alpha toxin (AT) and hypothetical protein (HP), and we subsequently identified B-cell epitopes in HP. In the present study, we identified B-cell epitopes in AT recognized by chickens immune to NE. The gene fragments encoding immunodominant epitopes of AT as well as those of HP were codon optimized for Salmonella and cloned into pYA3493, and the resultant plasmid constructs were introduced into an attenuated Salmonella enterica serovar Typhimurium χ9352 vaccine vehicle. The expression of these C lostridium perfringens proteins, alpha toxoid (ATd) and truncated HP (HPt), was confirmed by immunoblotting. The protection of broiler chickens against experimentally induced NE was assessed at both the moderate and the severe levels of challenge. Birds immunized orally with Salmonella expressing ATd were significantly protected against moderate NE, and there was a nonsignificant trend for protection against severe challenge, whereas HPt-immunized birds were significantly protected against both severities of challenge. Immunized birds developed serum IgY and mucosal IgA and IgY antibody responses against Clostridium and Salmonella antigens. In conclusion, this study identified, for the first time, the B-cell epitopes in AT from an NE isolate recognized by chickens and showed the partial protective ability of codon-optimized ATd and HPt against NE in broiler chickens when they were delivered orally by using a Salmonella vaccine vehicle.

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Kajikawa, Akinobu, Kazuya Masuda, Mitsunori Katoh, and Shizunobu Igimi. "Adjuvant Effects for Oral Immunization Provided by Recombinant Lactobacillus casei Secreting Biologically Active Murine Interleukin-1β." Clinical and Vaccine Immunology 17, no. 1 (November 18, 2009): 43–48. http://dx.doi.org/10.1128/cvi.00337-09.

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ABSTRACT Vaccine delivery systems using lactic acid bacteria are under development, but their efficiency is insufficient. Autologous cytokines, such as interleukin-1β (IL-1β), are potential adjuvants for mucosal vaccines and can be provided by recombinant lactic acid bacteria. The aim of this study was the construction and evaluation of recombinant Lactobacillus casei producing IL-1β as an adjuvant delivery agent. The recombinant strain was constructed using an expression/secretion vector plasmid, including a mature IL-1β gene from mouse. The biological activity of the cytokine was confirmed by IL-8 production from Caco-2 cells. In response to the recombinant L. casei secreting IL-1β, expression of IL-6 was detected in vivo using a ligated-intestinal-loop assay. The release of IL-6 from Peyer's patch cells was also detected in vitro. Intragastric immunization with heat-killed Salmonella enterica serovar Enteritidis (SE) in combination with IL-1β-secreting lactobacilli resulted in relatively high SE-specific antibody production. In this study, it was demonstrated that recombinant L. casei secreting bioactive murine IL-1β provided adjuvant effects for intragastric immunization.

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Lásaro, Marcio O., Wilson B. Luiz, Maria E. Sbrogio-Almeida, Lucilia S. Nishimura, Beatriz E. C. Guth, and Luis C. S. Ferreira. "Combined Vaccine Regimen Based on Parenteral Priming with a DNA Vaccine and Administration of an Oral Booster Consisting of a Recombinant Salmonella enterica Serovar Typhimurium Vaccine Strain for Immunization against Infection with Human-Derived Enterotoxigenic Escherichia coli Strains." Infection and Immunity 72, no. 11 (November 2004): 6480–91. http://dx.doi.org/10.1128/iai.72.11.6480-6491.2004.

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ABSTRACT Repeated evidence has demonstrated that combined primer-booster immunization regimens can improve both secreted and humoral immune responses to antigens derived from viral, bacterial, and parasitic pathogens. For the present work, we evaluated the synergic serum immunoglobulin G (IgG) and fecal IgA antibody responses elicited in BALB/c mice who were intramuscularly primed with a DNA vaccine, pRECFA, followed by oral boosting with an attenuated Salmonella enterica serovar Typhimurium vaccine (HG3) strain, with both vaccines encoding the structural subunit (CfaB) of the CFA/I fimbriae produced by human-derived enterotoxigenic Escherichia coli (ETEC) strains. The immunological properties of the vaccine regimen were evaluated according to the order of the administered vaccines, the nature of the oral antigen carrier, the age of the vaccinated animals, the interval between the priming and boosting doses, and the amount of injected DNA. The production of gamma interferon and the IgG2a subclass in serum indicated that mice immunized with the primer-booster regimen developed prevailing type 1 T-cell-dependent immune responses. The synergic effect of the vaccine regimen on the induced antibody responses was also revealed by its ability to block the adhesive properties of CFA/I fimbriae expressed by live bacteria, as shown by the inhibition of Caco-2 cell and human erythrocyte binding. Moreover, DBA2 newborn mice were protected from lethal challenges with a CFA/I+ ETEC strain after the incubation of live bacteria with serum samples harvested from mice who were subjected to the primer-booster regimen. We propose, therefore, that the DNA primer-Salmonella booster regimen represents an alternative for the development of vaccines requiring both mucosal and systemic antibody responses for immunological protection.

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Garmory, Helen S., Matthew W. Leckenby, Kate F. Griffin, Stephen J. Elvin, Rosa R. Taylor, M. Gill Hartley, Julian A. J. Hanak, E. Diane Williamson, and Rocky M. Cranenburgh. "Antibiotic-Free Plasmid Stabilization by Operator-Repressor Titration for Vaccine Delivery by Using Live Salmonella enterica Serovar Typhimurium." Infection and Immunity 73, no. 4 (April 2005): 2005–11. http://dx.doi.org/10.1128/iai.73.4.2005-2011.2005.

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ABSTRACT Live, attenuated bacteria are effective vectors for heterologous antigen delivery. However, loss of heterologous gene-bearing plasmids is problematic, and antibiotics and their resistance genes are not desirable for in vivo DNA vaccine delivery due to biosafety and regulatory concerns. To solve this problem, we engineered the first vaccine delivery strain that has no requirement for antibiotics or other selectable marker genes to maintain the recombinant plasmid. This model strain of Salmonella enterica serovar Typhimurium, SLDAPD, uses operator-repressor titration (ORT) technology, which requires only the short, nonexpressed lacO sequence for selection and maintenance. SLDAPD, recovered from the spleens and Peyer's patches of mice following oral inoculation, was shown to maintain a plasmid that, in contrast, was lost from parental strain SL3261. We also demonstrated successful application of this technology to vaccine development, since SLDAPD carrying a plasmid without an antibiotic resistance gene that expressed the Yersinia pestis F1 antigen was as efficacious in protecting vaccinated mice against plague as the parental SL3261 strain carrying an antibiotic-selected version of this plasmid. Protection of mice against plague by immunization with Salmonella expressing F1 has previously required two or more doses; here we demonstrated for the first time protective immunity after a single oral immunization. This technology can easily be used to convert any suitable attenuated strain to an antibiotic-free ORT strain for recombinant protein vaccine delivery in humans.

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Wang, Shifeng, Yuhua Li, Huoying Shi, Giorgio Scarpellini, Ascencion Torres-Escobar, Kenneth L. Roland, and Roy Curtiss. "Immune Responses to Recombinant Pneumococcal PsaA Antigen Delivered by a Live Attenuated Salmonella Vaccine." Infection and Immunity 78, no. 7 (May 17, 2010): 3258–71. http://dx.doi.org/10.1128/iai.00176-10.

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ABSTRACT Streptococcus pneumoniae is a leading cause of morbidity and mortality among children worldwide and particularly in developing countries. In this study, we evaluated PsaA, a conserved antigen important for S. pneumoniae adhesion to and invasion into nasopharynx epithelia, for its ability to induce protective immunity against S. pneumoniae challenge when delivered by recombinant attenuated Salmonella vaccine (RASVs) strains. RASVs were engineered to synthesize PsaA peptides of various lengths. Vaccination with an RASV synthesizing full-length PsaA induced high titers of anti-PsaA antibodies in both systemic (IgG in serum) and mucosal (IgA in vaginal washes, nasal washes, and lung homogenates) sites. BALB/c (haplotype H2d) or C57BL/6 (haplotype H2b) mice vaccinated either orally or intranasally exhibited a significant reduction in colonization of nasopharyngeal tissues after intranasal challenge with S. pneumoniae strains compared to controls, although protection was not observed with all challenge strains. None of the vaccine constructs provided protection against intraperitoneal challenge with S. pneumoniae strain WU2 (serotype 3). Immunization with RASVs synthesizing truncated PsaA generated lower titers of IgA and IgG and did not provide significant protection. Our results showed that RASVs synthesizing full-length PsaA can provide protection against nasal colonization by some S. pneumoniae strains. PsaA may be a useful addition to a multivalent vaccine, providing protection against pneumonia, otitis media, and other diseases caused by S. pneumoniae.

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Bumann, Dirk. "In Vivo Visualization of Bacterial Colonization, Antigen Expression, and Specific T-Cell Induction following Oral Administration of Live Recombinant Salmonella enterica Serovar Typhimurium." Infection and Immunity 69, no. 7 (July 1, 2001): 4618–26. http://dx.doi.org/10.1128/iai.69.7.4618-4626.2001.

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ABSTRACT Live attenuated Salmonella strains that express a foreign antigen are promising oral vaccine candidates. Numerous genetic modifications have been empirically tested, but their effects on immunogenicity are difficult to interpret since important in vivo properties of recombinant Salmonella strains such as antigen expression and localization are incompletely characterized and the crucial early inductive events of an immune response to the foreign antigen are not fully understood. Here, methods were developed to directly localize and quantitate the in situ expression of an ovalbumin model antigen in recombinant Salmonella enterica serovar Typhimurium using two-color flow cytometry and confocal microscopy. In parallel, the in vivo activation, blast formation, and division of ovalbumin-specific CD4+ T cells were followed using a well-characterized transgenic T-cell receptor mouse model. This combined approach revealed a biphasic induction of ovalbumin-specific T cells in the Peyer's patches that followed the local ovalbumin expression of orally administered recombinant Salmonellacells in a dose- and time-dependent manner. Interestingly, intactSalmonella cells and cognate T cells seemed to remain in separate tissue compartments throughout induction, suggesting a transport of killed Salmonella cells from the colonized subepithelial dome area to the interfollicular inductive sites. The findings of this study will help to rationally optimize recombinantSalmonella strains as efficacious live antigen carriers for oral vaccination.

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Berchtold, Christina, Klaus Panthel, Stefan Jellbauer, Brigitte Köhn, Elisabeth Roider, Miriam Partilla, Jürgen Heesemann, Stefan Endres, Carole Bourquin, and Holger Rüssmann. "Superior Protective Immunity against Murine Listeriosis by Combined Vaccination with CpG DNA and Recombinant Salmonella enterica Serovar Typhimurium." Infection and Immunity 77, no. 12 (September 21, 2009): 5501–8. http://dx.doi.org/10.1128/iai.00700-09.

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ABSTRACT Preexisting antivector immunity can severely compromise the ability of Salmonella enterica serovar Typhimurium live vaccines to induce protective CD8 T-cell frequencies after type III secretion system-mediated heterologous protein translocation in orally immunized mice. To circumvent this problem, we injected CpG DNA admixed to the immunodominant p60217-225 peptide from Listeria monocytogenes subcutaneously into BALB/c mice and coadministered a p60-translocating Salmonella strain by the orogastric route. The distribution of tetramer-positive p60217-225-specific effector and memory CD8 T cells was analyzed by costaining of lymphocytes with CD62L and CD127. In contrast to the single oral application of recombinant Salmonella or single immunization with CpG and p60, in the spleens from mice immunized with a combination of both vaccine types a significantly higher level of p60-specific CD8 T cells with a predominance of the effector memory T-cell subset was detected. In vivo protection studies revealed that this CD8 T-cell population conferred sterile protective immunity against a lethal infection with L. monocytogenes. However, p60-specific central memory CD8 T cells induced by single vaccination with CpG and p60 were not able confer effective protection against rapidly replicating intracellular Listeria. In conclusion, we provide compelling evidence that the combination of Salmonella type III-mediated antigen delivery and CpG immunization is an attractive novel vaccination strategy to modulate CD8 differentiation patterns toward distinct antigen-specific T-cell subsets with favorable protective capacities.

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Dankel, Dorothy J., Kenneth L. Roland, Michael Fisher, Karen Brenneman, Ana Delgado, Javier Santander, Chang-Ho Baek, Josephine Clark-Curtiss, Roger Strand, and Roy Curtiss. "Making Common Sense of Vaccines: An Example of Discussing the Recombinant Attenuated Salmonella Vaccine with the Public." NanoEthics 8, no. 2 (July 10, 2014): 179–85. http://dx.doi.org/10.1007/s11569-014-0198-6.

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Xu, Can. "Construction of recombinant attenuated Salmonella typhimurium DNA vaccine expressingH pyloriureB and IL-2." World Journal of Gastroenterology 13, no. 6 (2007): 939. http://dx.doi.org/10.3748/wjg.v13.i6.939.

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Chin'ombe, Nyasha. "Recombinant Salmonella enterica Serovar Typhimurium as a Vaccine Vector for HIV-1 Gag." Viruses 5, no. 9 (August 28, 2013): 2062–78. http://dx.doi.org/10.3390/v5092062.

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Ashby, Deborah, Isabelle Leduc, Wallace Lauzon, B. Craig Lee, Neera Singhal, and D. William Cameron. "Attenuated Salmonella typhimurium SL3261 as a vaccine vector for recombinant antigen in rabbits." Journal of Immunological Methods 299, no. 1-2 (April 2005): 153–64. http://dx.doi.org/10.1016/j.jim.2005.02.005.

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Cieslak, Paul R., Zhang Tonghai, and Samuel L. Stanley Jr. "Expression of a recombinant Entamoeba histolytica antigen in a Salmonella typhimurium vaccine strain." Vaccine 11, no. 7 (May 1993): 773–76. http://dx.doi.org/10.1016/0264-410x(93)90264-x.

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Prejit, Rajesh Kumar Agarwal, Kannan Porteen, Zunjar B. Dubal, Karthikeyan Asha, Singh Shweta, and Biswas Ripan. "Evaluation of recombinant outer membrane protein based vaccine against Salmonella Typhimurium in birds." Biologicals 41, no. 3 (May 2013): 162–68. http://dx.doi.org/10.1016/j.biologicals.2013.01.003.

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Konjufca, Vjollca, Mark Jenkins, Shifeng Wang, Maria Dolores Juarez-Rodriguez, and Roy Curtiss. "Immunogenicity of Recombinant Attenuated Salmonella enterica Serovar Typhimurium Vaccine Strains Carrying a Gene That Encodes Eimeria tenella Antigen SO7." Infection and Immunity 76, no. 12 (September 22, 2008): 5745–53. http://dx.doi.org/10.1128/iai.00897-08.

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ABSTRACT Recombinant attenuated Salmonella vaccines against avian coccidiosis were developed to deliver Eimeria species antigens to the lymphoid tissues of chickens via the type 3 secretion system (T3SS) and the type 2 secretion system (T2SS) of Salmonella. For antigen delivery via the T3SS, the Eimeria tenella gene encoding sporozoite antigen SO7 was cloned downstream of the translocation domain of the Salmonella enterica serovar Typhimurium sopE gene in the parental pYA3868 and pYA3870 vectors to generate pYA4156 and pYA4157. Newly constructed T3SS vectors were introduced into host strain χ8879 (ΔphoP233 ΔsptP1033::xylE ΔasdA16), an attenuated derivative of the highly virulent UK-1 strain. The SopE-SO7 fusion protein was secreted by the T3SS of Salmonella. The vector pYA4184 was constructed for delivery of the SO7 antigen via the T2SS. The SO7 protein was toxic to Salmonella when larger amounts were synthesized; thus, the synthesis of this protein was placed under the control of the lacI repressor gene, whose expression in turn was dependent on the amount of available arabinose in the medium. The pYA4184 vector was introduced into host strain χ9242 (ΔphoP233 ΔasdA16 ΔaraBAD23 ΔrelA198::araC PBAD lacI TT [TT is the T4ipIII transcription terminator]). In addition to SO7, for immunization and challenge studies we used the EAMZ250 antigen of Eimeria acervulina, which was previously shown to confer partial protection against E. acervulina challenge when it was delivered via the T3SS. Immunization of chickens with a combination of the SO7 and EAMZ250 antigens delivered via the T3SS induced superior protection against challenge by E. acervulina. In contrast, chickens immunized with SO7 that was delivered via the T2SS of Salmonella were better protected from challenge by E. tenella.

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Wang, Zhihao, Jielan Mi, Yulong Wang, Tingting Wang, Xiaole Qi, Kai Li, Qing Pan, et al. "Recombinant Lactococcus Expressing a Novel Variant of Infectious Bursal Disease Virus VP2 Protein Can Induce Unique Specific Neutralizing Antibodies in Chickens and Provide Complete Protection." Viruses 12, no. 12 (November 25, 2020): 1350. http://dx.doi.org/10.3390/v12121350.

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Recent reports of infectious bursal disease virus (IBDV) infections in China, Japan, and North America have indicated the presence of variant, and the current conventional IBDV vaccine cannot completely protect against variant IBDV. In this study, we constructed recombinant Lactococcus lactis (r-L. lactis) expressing a novel variant of IBDV VP2 (avVP2) protein along with the Salmonella resistance to complement killing (RCK) protein, and Western blotting analysis confirmed that r-L. lactis successfully expressed avVP2-RCK fusion protein. We immunized chickens with this vaccine and subsequently challenged them with the very virulent IBDV (vvIBDV) and a novel variant wild IBDV (avIBDV) to evaluate the immune effect of the vaccine. The results show that the r-L. lactis-avVP2-RCK-immunized group exhibited a 100% protection rate when challenged with avIBDV and 100% survival rate to vvIBDV. Furthermore, this immunization resulted in the production of unique neutralizing antibodies that cannot be detected by conventional ELISA. These results indicate that r-L. lactis-avVP2-RCK is a promising candidate vaccine against IBDV infections, which can produce unique neutralizing antibodies that cannot be produced by other vaccines and protect against IBDV infection, especially against the variant strain.

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Bird, Peter, Christine Hayes, James de Jersey, and Mark Bradley. "Construction and immunological assessment of Salmonella typhimurium expressing fox sperm LDH-C4." Reproduction, Fertility and Development 10, no. 3 (1998): 225. http://dx.doi.org/10.1071/r97076.

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This study examined immune responses of foxes to oral doses of recombinant Salmonella typhimurium expressing fox sperm-specific lactate dehydrogenase (fLDH). The cDNA for fLDH was cloned into the expression plasmid pKK233· 2 (pKKfLDH). Salmonella typhimuriumaroA– (SL3261) was transformed with either the pKK233·2 plasmid alone (SpKK) or the pKKfLDH construct (SpKfLDH). The fLDH expressed by SpKfLDH retained enzymatic activity and was recognized by human LDH-C4-specific antibody. Male European red foxes (Vulpes vulpes) were given an initial oral dose of 1 × 1011 cfu of either SpKK (control, n = 3) or SpKfLDH (test, n = 6), followed four weeks later with a further dose of 1 × 1011 cfu. Antibodies to Salmonella lipopolysaccharide (LPS-04) and fLDH were measured in plasma and saliva for eight consecutive weeks after the initial doses. Both LPS-04 IgG- and IgA-specific antibodies as well as fLDH-specific IgG antibodies were detected in plasma and saliva. However, there was a marked fLDH-specific IgA response in saliva consistent with induction of the common mucosal immune system. The antibody measurements demonstrated the feasibility of using recombinant Salmonella as an oral vaccine to elicit gamete antigen-specific mucosal immune responses in foxes.

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Ghose, Chandrabali, Janneke M. Verhagen, Xinhua Chen, Jian Yu, Yaoxing Huang, Olivia Chenesseau, Ciarán P. Kelly, and David D. Ho. "Toll-Like Receptor 5-Dependent Immunogenicity and Protective Efficacy of a Recombinant Fusion Protein Vaccine Containing the Nontoxic Domains of Clostridium difficile Toxins A and B and Salmonella enterica Serovar Typhimurium Flagellin in a Mouse Model of Clostridium difficile Disease." Infection and Immunity 81, no. 6 (April 1, 2013): 2190–96. http://dx.doi.org/10.1128/iai.01074-12.

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ABSTRACTClostridium difficileis a spore-forming bacillus that produces toxin-mediated enteric disease.C. difficileexpresses two major virulence factors, toxin A (TcdA) and toxin B (TcdB). Human and animal studies demonstrate a clear association between humoral immunity to these toxins and protection againstC. difficileinfection (CDI). The receptor binding-domains (RBDs) of TcdA and TcdB are known to be immunogenic. Here, we tested the immunoadjuvant properties ofSalmonella entericaserovar Typhimurium flagellin (FliC) subunit D1 as an innate immune agonist expressed as a recombinant fusion vaccine targeting the RBDs of TcdA and TcdB in mice. Intraperitoneally immunized mice developed prominent anti-TcdA and anti-TcdB immunoglobulin G in serum. The protective efficacy of the recombinant vaccines, with or without an adjuvant, was tested in a mouse model of CDI that closely represents the human disease. Following intraperitoneal immunization equivalent to two doses of toxoid A and toxoid B vaccine adjuvanted with alum and oral challenge withC. difficileVPI 10463, C57BL/6 mice were able to mount a protective immune response that prevented diarrhea and death compared to mice immunzed with alum alone. These results are significantly different from those for control mice (P< 0.001). These results provide evidence that a recombinant protein-based vaccine targeting the RBDs of theC. difficiletoxins adjuvanted withS. Typhimurium flagellin can induce rapid, high-level protection in a mouse model of CDI when challenged with the homologous strain from which the vaccine antigens were derived and warrant further preclinical testing against clinically relevantC. difficilestrains in the mouse and hamster models of CDI.

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Soo, Shiu-Shing, Bernardo Villarreal-Ramos, C. M. Anjam Khan, Carlos E. Hormaeche, and Jenefer M. Blackwell. "Genetic Control of Immune Response to Recombinant Antigens Carried by an Attenuated Salmonella typhimuriumVaccine Strain: Nramp1 Influences T-Helper Subset Responses and Protection against Leishmanial Challenge." Infection and Immunity 66, no. 5 (May 1, 1998): 1910–17. http://dx.doi.org/10.1128/iai.66.5.1910-1917.1998.

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ABSTRACT Attenuated strains of Salmonella typhimurium have been widely used as vehicles for delivery and expression of vaccine antigens in murine models of infectious disease. In mice, early bacterial replication following infection with S. typhimurium is controlled by the gene (Nramp1, formerlyIty/Lsh/Bcg) encoding the natural-resistance-associated macrophage protein (Nramp1). Nramp1 regulates macrophage activation and has multiple pleiotropic effects, including regulation of tumor necrosis factor alpha, interleukin 1β (IL-1β), and major histocompatibility complex class II molecules, all of which influence antigen processing and presentation. Nramp1 also has a direct effect on antigen processing, possibly by regulating the activity of proteases in the late endosomal compartment. Hence, there are multiple ways (regulation of bacterial load or recombinant antigen dose, class II molecule expression, costimulatory or adjuvant activity, and antigen processing) that Nramp1 might influence responses to recombinant salmonella vaccines. To test the hypothesis that Nramp1 influences responses to vaccination, congenic mouse strains have been used to analyze immune responses to recombinant antigens (tetanus toxoid antigen and leishmanial gp63) carried by live attenuated S. typhimurium aroA aroD mutants. Results show that congenic mice carrying the wild-type (S. typhimurium resistance)Nramp1 allele mount a predominantly T-helper-1 (IL-2 and gamma interferon) response to vaccination and show enhanced resolution of lesions following challenge infection with Leishmania major. In contrast, mice carrying mutant (S. typhimurium susceptibility) Nramp1 mount a T-helper-2 (immunoglobulin E and IL-4) response and show exacerbated lesion growth upon challenge.

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Pan, Zhiming, Qiuxia Cong, Shizhong Geng, Qiang Fang, Xilong Kang, Meng You, and Xinan Jiao. "Flagellin from Recombinant Attenuated Salmonella enterica Serovar Typhimurium Reveals a Fundamental Role in Chicken Innate Immunity." Clinical and Vaccine Immunology 19, no. 3 (January 11, 2012): 304–12. http://dx.doi.org/10.1128/cvi.05569-11.

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ABSTRACTRecombinant attenuatedSalmonellavaccines have been extensively studied, with a focus on eliciting specific immune responses against foreign antigens. However, very little is known about the innate immune responses, particularly the role of flagellin, in the induction of innate immunity triggered by recombinant attenuatedSalmonellain chickens. In the present report, we describe twoSalmonella entericaserovar Typhimurium vaccine strains, wild-type (WT) or flagellin-deficient (flhD)Salmonella, both expressing the fusion protein (F) gene of Newcastle disease virus. We examined the bacterial load and spatiotemporal kinetics of expression of inflammatory cytokine, chemokine, and Toll-like receptor 5 (TLR5) genes in the cecum, spleen, liver, and heterophils following oral immunization of chickens with the twoSalmonellastrains. TheflhDmutant exhibited an enhanced ability to establish systemic infection compared to the WT. In contrast, the WT strain induced higher levels of interleukin-1β (IL-1β), CXCLi2, and TLR5 mRNAs in cecum, the spleen, and the heterophils than theflhDmutant at different times postinfection. Collectively, the present data reveal a fundamental role of flagellin in the innate immune responses induced by recombinant attenuatedSalmonellavaccines in chickens that should be considered for the rational design of novel vaccines for poultry.

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Journal articles on the topic 'Recombinant Salmonella vaccine'

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