Dissertations / Theses: 'Antigen-antibody complexes'

1

Mustafa, Awder. "Circulating immune complexes in atherosclerotic vascular disease /." Stockholm : Karolinska Univ. Press, 2001. http://diss.kib.ki.se/2001/91-7349-018-0/.

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Hanke, Tomas. "Development of solid matrix-antibody-antigen (SMAA) complexes as multivalent subunit vaccines." Thesis, University of St Andrews, 1994. http://hdl.handle.net/10023/13989.

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In the course of the work presented in this thesis, the construction of solid matrix-antibody-antigen (SMAA) complexes as vaccines was further developed. In particular, it was demonstrated that it is feasible to assemble SMAA complexes using a short oligopeptide tag (Pk) attached to the C-termini of antigens and a Pk tag- specific mAb SV5-P-k. In order to facilitate the purification of recombinant proteins for immunization purposes, a second affinity tag was attached to the antigen N-termini. Initially, the N-terminal tag was 26-kDa-large thrombin-removable glutathione S-transferase (GST), which permitted first-step purification on immobilized glutathione. However, because of problems with protein insolubility and the proteolytical removal of GST from the hybrid proteins, the GST domain was substituted by an N-terminal 12-amino acid-long tag (His) containing an array of 6 histidines. The His tag was small and thus did not require removal prior to immunization, and allowed purification of His-linked proteins on a nickel-affinity column. Moreover, it was possible to preform nickel-affinity chromatography under protein denaturing conditions, which allowed purification of insoluble or aggregated proteins. In addition, novel prokaryotic expression vectors were constructed for a single-cloning-step addition of these N- and C-terminal tags to proteins of interest. These vectors were used to individually express all non-glycosylated products encoded by the simian immunodeficiency virus (SIV) in E. coli. The SIV envelope glycoprotein gp160 with the Pk tag attached to its C-terminus was expressed in insect cells and first-step purified on a lentile lectin column. Following the first purification step on either nickel or lentile columns, all SIV proteins were purified and successfully incorporated into SMAA complexes using anti-Pk tag mAb SV5-P-k. Thus, efficient purification protocols were developed, which purified recombinant proteins via two different affinity tags attached to their N- and C-termini and isolated predominantly full-size proteins. As a stage in achieving the goal of human multivalent vaccines, the SV5-P-k mAb was humanized and is currently being expressed in Chinese hamster ovary cells.

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Green, Elizabeth Allison. "The development and use of antigen-antibody-LTB (Ag-MAb-LTB) complexes as immunogens." Thesis, University of St Andrews, 1995. http://hdl.handle.net/10023/13984.

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In the course of this work a novel strategy has been developed for linking the adjuvant Escherichia coli heat-labile enterotoxin subunit B (LTB) to Simian Immunodeficiency Virus (SIV) proteins via an antibody bridge and the systemic and mucosal immunogenicity of such SIV-MAb-LTB complexes have been investigated. A short peptide tag, termed Pk, was joined to the 3'-end of the gene coding for LTB and expression studies revealed that the gene product, LTB-Pk, could be efficiently synthesised and secreted from non-pathogenic Vibrio sp.60. Analysis of the functional properties of LTB-Pk demonstrated that LTB-Pk , like native LTB, was a heat-labile oligomer, that could bind to the glycolipid GM1-ganglioside and was immunogenic in vivo. In attempts to purify LTB-Pk for immunisation studies, both hydrophobic and ion-exchange chromatography schedules were analysed, the latter procedure being more efficient. Strategies were developed for joining LTB-Pk to one arm of an anti-Pk MAb, (MAb SV5-P- k) and Pk-linked SIV proteins to the other arm, and such SFV-MAb-LTB complexes bound to GM1 -ganglioside in vitro. Systemic immunisation studies suggested that SIV-MAb-LTB complexes, using recombinant p17 as the target antigen, promoted both humoral and cell- mediated immunity to the recombinant p17. In addition, it was later shown that conjugation of LTB-Pk to recombinant SIV proteins via an antibody bridge, resulted in a more efficent presentation of the recombinant SIV protein to the immune system, than co-administration of LTB-Pk with the recombinant SIV protein. However, intranasal administration of p17-MAb-LTB complexes did not induce immunity to recombinant p17. Subsequently it was shown that the recombinant p17 was highly susceptible to mucosal degradation, suggesting the poor mucosal immunogenicity of p17-MAb-LTB complexes may be related to the instability of recombinant p17 in the mucosal environment. Further investigations into the stability of other recombinant SIV proteins in the mucosa, revealed that recombinant p27 was more resilient to mucosal degradation. p27-MAb-LTB complexes were constructed and initial intranasal immunisation studies revealed that both systemic and cell-mediated immunity to recombinant p27, could be induced following intranasal administration. Furthermore, mucosal immunity to recombinant p27 was evident in the lungs of vaccinated mice, with anti-recombinant p27 IgG-secreting cells predominating.

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Barbar, Elisar Jamil. "Nuclear Magnetic Resonance Study of Antigen-Antibody Complexes, Including Sequence Specific Assignments and Structural Analysis of Neurophysin as an Antigen Model." PDXScholar, 1993. https://pdxscholar.library.pdx.edu/open_access_etds/1167.

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The interaction between molecules is essential in a wide range of biological processes. A detailed knowledge of these interactions is necessary for understanding these processes. Among the systems that involve important interactions is the immune system. NMR spectroscopy has a large number of spectral parameters that were used in this work to study antibody-antigen interactions. These same parameters were also used to begin a structural analysis of a medium-sized protein, neurophysin, that has important interactions with neurohormones, and served here as a model antigen. A set of ligands differing in size and charge was designed and used to probe the binding site of anti-phosphocholine antibodies. These ligands ranged from small organic species to medium sized proteins. Amino acids, peptides and proteins were homogeneously linked to phenyl phosphocholine and analyzed by NMR techniques. Transferred nuclear Overhauser effect measurements were used to determine the conformation of bound ligands. The conformational change observed in some ligands was explained as either due to the antibody selecting one conformation that already exists, or the antibody binding inducing a conformational change. Titration data and detailed NMR analysis showed a more rigid M3C65 antibody fragment upon binding. In summary, with eight examples of ligands and four examples of antibodies studied by NMR, a spectrum of effects was seen, including a lock-and-key model and limited local induced fit. The contribution of the carrier molecule to antibody binding was in restricting the conformation of the ligand. Bigger ligands that are expected to be more immunogenic, showed less binding avidity as determined by immunological assays. Fluorinated ligands were synthesized to determine the kinetics of binding using 19F NMR spectra. Higher concentration of a fragment of the antibody M3C65 was analyzed to determine assignments of some residues in the combining site of the antibody. High resolution NMR techniques were used to assign resonances in neurophysin. The physiological role of neurophysin includes hormone storage and stabilization of oxytocin and vasopressin against proteolytic degradation within the posterior pituitary. Neurophysin is a 10 KD protein that dimerizes at high concentrations needed for NMR studies. An organic cosolvent was used to lower the dimerization constant, and hence inrease the spectral resolution. This permitted sequence-specific assignments that were then used to identify residues in the neurophysin-hormone binding site. Chemical shift differences and conformational changes were observed for the residues glutamate 47 and leucine 50. The 3₁₀ helix was further stabilized towards a more ideal helix upon hormone-analog peptide binding. Some of the residues contributing to the monomer-monomer interface were also assigned. Dimerization ill1duced chemical shift differences and conformational changes were observed for phenylalanine 35, threonine 38, and alanine 69. Tyrosine: 49 and phenylalanine 22 were affected but to a lesser extent. One characteristic of neurophysin in all studied cases was dynamic equilibrium between different folding states.

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Natale, Sara. "Utilising antigen-antibody complexes for the immunomagnetic enrichment of spermatozoa from sexual assault intimate swabs." Thesis, Natale, Sara (2021) Utilising antigen-antibody complexes for the immunomagnetic enrichment of spermatozoa from sexual assault intimate swabs. Masters by Research thesis, Murdoch University, 2021. https://researchrepository.murdoch.edu.au/id/eprint/64502/.

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Sexual assault is prevalent within today’s society with 18% of women reporting sexual assault within their lifetime (1). Physical evidence collected from a forensic examination may include an intimate swab. The standard method used for sperm isolation is differential lysis however, the high abundance of vaginal epithelial cells on vaginal sexual assault swabs complicates the protocol. This factor results in mixed DNA profiles with an overabundance of female DNA present in an autosomal STR profile. Mixed STR profiles make it difficult to interpret the male DNA profile and therefore cannot always be used in court to identify a perpetrator. An antibody-based method for spermatozoa extraction using antibody conjugated immunomagnetic beads to select for sperm could be used as a method of enrichment, producing a higher yield of recovered male DNA. To achieve this, sperm-specific antibodies are needed to selectively bind to the sperm when in an epithelial/sperm cell mixture. This study aimed to identify the capability of 3 antibodies, α-SPAM1, α-SPACA1, and α-ZPBP with a secondary antibody Goat α-Rabbit IgG (H+L) Secondary Antibody, Alexa Fluor Plus 488 through flow cytometry. Canto™ II CA flow cytometer was used for the visualisation of sperm/vaginal epithelial cell cross-reactivity with the antibodies to determine the cell sensitivity and selectivity. Optimisation of the flow cytometry protocol was undertaken for both the epithelial and sperm cells. The antibodies had >20% cross-reactivity to the sperm cells and >30% to the vaginal epithelial cells however, the epithelial cells had a higher autofluorescence than expected with >30% positive unstained epithelial cells.

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Hutchinson, Sean. "Utilising antigen-antibody complexes to capture and enrich for sperm cells fractions in a mixed substrate." Thesis, Hutchinson, Sean (2017) Utilising antigen-antibody complexes to capture and enrich for sperm cells fractions in a mixed substrate. Masters by Coursework thesis, Murdoch University, 2017. https://researchrepository.murdoch.edu.au/id/eprint/38406/.

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Forensic DNA analysis on sexual assault evidence requires the separation of the victim and assailants DNA. For vaginal swabs where a large number of victims cells (epithelial cells) are present compared to the small number of the male assailants cells this can be problematic. There are a variety of methods that can achieve this separation and the most commonly used at present is differential lysis or variations upon this method. These methods tend to be long and tedious with results often relying on the operators’ expertise and experience. Immunomagnetic beads have been used in various other areas of the scientific community for separation of cells from various mixtures and the use of immunomagnetic beads for separation of sperm cells form cellular mixtures can potentially be used as an improvement upon current methods of separation. Antibodies have been tested for the use of forensically applied magnetic bead separation however there has been little testing beyond proof that it works. Optimisation of the procedure and testing on more realistic samples need to be conducted.

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Schiele, Felix [Verfasser], Michael [Akademischer Betreuer] Groll, and Thomas [Akademischer Betreuer] Kiefhaber. "Structural And Biophysical Characterization of Antibody-Antigen Complexes of Therapeutic Relevance / Felix Schiele. Gutachter: Michael Groll ; Thomas Kiefhaber. Betreuer: Michael Groll." München : Universitätsbibliothek der TU München, 2013. http://d-nb.info/1034952064/34.

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8

Sprenger, Kenneth John. "Circulating immune complexes in acute rheumatic carditis." Doctoral thesis, University of Cape Town, 1995. http://hdl.handle.net/11427/27055.

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The group A beta-haemolytic streptococcus is known to be the aetiologic agent in acute rheumatic fever, but the exact pathogenesis remains obscure. A review of the histopathology of the Aschoff body suggests that the cardiac pathology is a granulomatous hypersensitivity reaction. However the streptococcus has not been found in the lesions, and the agent responsible for the granuloma has not yet been identified. Circulating immune complexes have previously been measured in some children with acute rheumatic fever. The normal or raised complement components measured by some workers in acute rheumatic fever suggests that the immune complexes may not be complement fixing. Considering that the usual assays for measuring immune complexes depend on complement fixation, the failure of the immune complexes to fix complement might produce false negative results. A physical, non-complement fixing assay (polyethylene glycol precipitation - PEG), was therefore used to measure circulating immune complexes. Results were expressed as total IgG precipitated (g/L), or as a percentage of serum IgG. Immune complexes were also measured by two complement dependent assays, a Clq binding assay (ClqBA), and conglutinin binding assay (CBA). Complexes were assayed in 15 children with acute rheumatic carditis (ARC), 11 with non-active, chronic rheumatic heart disease (CRHD), 13 with acute poststreptococcal glomerulonephritis (APSGN), and 15 normal children and adults (NORMAL). Total haemolytic complement, complement components as well as the complement breakdown product C3d, were measured.

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9

Carvalho, Camila Aparecida de. "Estudo da presença e influência de antígenos parasitários na sorologia da Leishmaniose visceral." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/99/99131/tde-21022014-112702/.

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A Leishmaniose visceral é uma doença parasitária crônica em homens e cães, causada por protozoários da espécie L. (Leishmania) chagasi. O diagnóstico parasitológico é confirmado pelo achado do agente em aspirados de medula óssea, linfonodo, baço e fígado, enquanto que a sorologia IgG especifica é usada em geral para estudos epidemiológicos, apesar dos altos níveis séricos de anticorpos IgG anti-Leishmania. Existem relatos anedóticos de resultados sorológicos negativos em doença ativa, atribuído à formação de imunocomplexos. Dado que imunocomplexos podem ser dissociados por tratamento ácido, nós buscamos a padronização de um teste simples de dissociação ácida dos imunocomplexos de amostras de soro, por tratamento ácido e neutralização em poços adsorvidos com antígenos de Leishmania, seguida de ELISA (ELISA dissociativo). A confirmação da presença de antígenos foi realizada pela detecção após adsorção ácida por DOT-ELISA, usando soro de coelho hiperimune anti-Leishmania. Amostras de hamsteres infectados experimentalmente com L. (L.) chagasi mostraram a presença e interferência de imunocomplexos na sorologia principalmente nas fases iniciais da infecção, por ELISA dissociativo e DOT-ELISA. Em amostras maiores de áreas endêmicas, o ELISA dissociativo aumentou a soropositividade em 10% em amostras de cães negativas e 3,5% de amostras humanas negativas, com confirmação por DOT-ELISA. Os resultados mostram que este teste poderia ser usado no diagnóstico da LV, como abordagem alternativa para a identificação sorológica de casos assintomáticos e para indicação de métodos parasitológicos invasivos confirmatórios.
Visceral leishmaniasis, caused by Leishmania (Leishmania) chagasi, is a chronic parasitic disease of humans and dogs. Confirmation of the protozoal agent in bone marrow, lymph node or spleen aspirate is diagnostic, while specific-IgG serology is used mainly for epidemiology despite the general presence of high levels of serum immunoglobulins. Anecdotal reports of false-negative serology in active disease cases are known and are ascribed to the formation of immune complexes. Because dissociation of immune complexes can be accomplished by acid treatment, we devised a simple, routine enzyme immunoassay (ELISA) for the dissociation of immune complexes in serum samples using acid treatment and neutralization in wells adsorbed with Leishmania antigen (dELISA). Confirmatory acid DOT-ELISA was also developed for antigen detection by anti-Leishmania rabbit antiserum. In experimental L. (L.) chagasi hamster models, immune complexes interfered with ELISA mostly in the early stages of infection, according to both dELISA and antigen DOT-ELISA results. In larger samples from endemic areas, dELISA increased seropositivity by 10% in negative dog samples (7/70) and 3.5% in negative human samples (3/85), showing that dELISA could be used in the serodiagnosis of visceral leishmaniasis. Moreover, dELISA could be used as an alternative approach to screening asymptomatic visceral leishmaniasis patients, instead of invasive confirmatory testing.

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10

Mahmoud, Tamer I. "The significance of heavy chain CDR3 diversity in the antibody response to polysaccharides." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2009. https://www.mhsl.uab.edu/dt/2009p/mahmoud.pdf.

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11

Holm, Patrik. "Functional mapping and in vivo metabolism of the monoclonal antibody TS1 and its single-chain fragment : Its interaction with the antigen and the anti-idiotype." Doctoral thesis, Karlstad University, Faculty of Technology and Science, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-727.

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Antibodies are proteins capable of specific interactions to a wide range of molecules. These interactions are facilitated by the complementary determining regions (CDR).

Carcinomas are the most common of human cancers and they release significant amount of cytokeratins (CK) in the necrotic areas of the tumors. The CKs stay in the tumor, since they have low solubility. The antibody studied in this thesis, the anti-CK 8 antibody TS1, has shown to be effective in tumor targeting and is proposed to be useful in therapy.

Single-chain antibodies (scFv) are recombinant antibodies which are much smaller than the intact IgG. This is an advantage when used in tumor therapy, since they can penetrate the tumors more easily than the larger IgG. Moreover, they are expressed by one single gene which make them easy to modify, for example by site-directed mutagenesis.

The anti-idiotypic antibody αTS1 can be used to clear the TS1 form the circulation and thereby clear the body from non-tumor bound TS1 in therapy. To be able to modify the binding of an antibody to its antigen and or anti-idiotype, these interactions must be studied. In this study this is accomplished by chemical modifications of the IgGs TS1 and αTS1 and the antigen CK 8. Guided by these results, amino acid residues were mutated by using site-directed mutagenesis in the TS1-218 scFv and the effects were studied. From mutational study results, the functional epitope could be mapped and it was found that there are mainly tyrosines, but also charged residues, serine and a tryptophan that are important for both interactions. The binding of TS1-218 to both αTS1 and CK 8 could be improved by changing the negatively charged side-chains by mutations to their corresponding amide or alanine.

Both the IgG and scFv versions of TS1 were administered in vivo. The IgG αTS1 was used to clear the TS1 from the circulation by forming immune complexes. The immune complexes, consisting of four or more antibodies, were mainly metabolized by the liver. The scFv TS1-218 could localize to the tumor in a tumor xenograft mouse model, although a higher uptake would be desired in a therapeutic strategy. The scFv was cleared rapidly by the kidneys, but the clearance could be slowed by pre-formed immune complexes with anti-TS1 scFv in vitro, prior to administration in vivo.

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Mathsson, Linda. "Immune Complex Regulated Cytokine Production in Rheumatic and Lymphoproliferative Diseases." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7446.

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13

Santoro, Lyse. "Appretement et présentation d'un anticorps monoclonal murin par une lignée monocytaire ou lymphocytaire B humaine : influence de la liaison covalente entre anticorps et fragment C3b du complément." Grenoble 1, 1994. http://www.theses.fr/1994GRE10126.

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La proteine c3 du complement influence l'elaboration de la reponse immune specifique dirigee contre un antigene defini. L'etude presentee dans cette these contribue a demontrer que le fragment c3b du complement, en se fixant de facon covalente a un antigene d'origine exogene, module l'appretement de l'antigene par une cellule presentatrice de l'antigene. Des donnees bibliographiques recentes concernant l'appretement d'antigenes, le fragment c3b et son implication dans la reponse immune specifique sont presentees dans un chapitre d'introduction. L'etude experimentale decrite a ete realisee en utilisant des anticorps monoclonaux murins comme antigenes et des cellules monocytaires ou lymphocytaires b humaines comme cellules presentatrices ; des complexes covalents anticorps monoclonaux-c3b ont ete produits et caracterises. Les resultats obtenus sont exposes dans trois chapitres. Dans un premier chapitre, des experiences montrent que la presentation d'anticorps monoclonaux murins a des cellules t humaines specifiques de ces anticorps est modulee lorsqu'ils sont complexes au fragment c3b. Puis certaines des principales etapes de l'appretement des anticorps utilises sont caracterisees dans des cellules monocytaires u937 ou lymphocytaires b humaines non specifiques de l'antigene (fixation a des recepteurs membranaires, internalisation, transit intracellulaire, modifications biochimiques) ; enfin, l'influence de la liaison covalente entre anticorps et c3b sur ces differentes etapes est mise en evidence. Des hypotheses sont proposees concernant un role chaperon de c3b

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Lin, Yu-Wen, and 林玉雯. "Photoinduce Antibody-Antigen Complexes to Dissociate." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/68329454260731283348.

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碩士
國立清華大學
工程與系統科學系
94
This research proposes a photochemical method to dissociate immune complexes, decrease the hurt to protein of traditional acid washing by extremely shot operation time. We used the well-known characteristic of o-NBA molecules that can be photoinduced proton releasing by 365nm irradiation and make pH jump in the solution to dissociate immune complexes. In order to prove our proposal, we set up a flowing system, fixed antibody which has fluorescence and antigen modified with quencher which can quench the fluorescence in it. Because the effective distant of quencher quenches fluorescence is very shot (~10nm), only when antigens binds to antibodies, the distant is shot enough to quench the fluorescence. We judgment if antibody and antigen bind or not by fluorescence was quenched or not. The fluorescent dye we chose was quantum dots because of its fluorescence won’t be influenced by the pH value changes in the environment. Base on our results of experiments this method is workable, and it got similar recovery ratio to the solution pH=3.

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Jhuang, Shu-Ting, and 莊淑婷. "Surface Confined Photo-induced Proton for Antibody-antigen Complexes Dissociation." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/93375424365457260072.

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16

Venkatesh, N. "Monoclonal Antibodies As Probes To Protein Structure And Function : Studies On Human Chorionic Gonadotropin." Thesis, 1997. http://etd.iisc.ernet.in/handle/2005/1786.

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17

Perdue, Samuel Scott. "Structural, functional and energetic analysis of antibodies in complex with staphylococcal nuclease /." 1997. http://wwwlib.umi.com/dissertations/fullcit/9724678.

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Dissertations / Theses on the topic 'Antigen-antibody complexes'

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