Articles de revues : « Activation polyclonal »

1

Goldman, Michel, Dana Baran et Philippe Druet. « Polyclonal activation and experimental nephropathies ». Kidney International 34, n^o 2 (août 1988) : 141–50. http://dx.doi.org/10.1038/ki.1988.159.

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Chequer-Bou-Habib, Dumith, Claudio Daniel-Ribeiro, Dalma M. Banic, Antonio C. Franciscone do Valle et Bernardo Galvao-Castro. « Polyclonal B cell activation in paracoccidioidomycosis ». Mycopathologia 108, n^o 2 (novembre 1989) : 89–93. http://dx.doi.org/10.1007/bf00436058.

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Dziarski, Roman. « Autoimmunity : polyclonal activation or antigen induction ? » Immunology Today 9, n^o 11 (janvier 1988) : 340–42. http://dx.doi.org/10.1016/0167-5699(88)91333-3.

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Tew, John, David Engel et Dennis Mangan. « Polyclonal B-cell activation in periodontitis* ». Journal of Periodontal Research 24, n^o 4 (juillet 1989) : 225–41. http://dx.doi.org/10.1111/j.1600-0765.1989.tb01787.x.

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Kaattari, Stephen L., et Mary A. Yui. « Polyclonal activation of salmonid B lymphocytes ». Developmental & ; Comparative Immunology 11, n^o 1 (décembre 1987) : 155–65. http://dx.doi.org/10.1016/0145-305x(87)90017-6.

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Barbieri, P., I. Olivieri, G. Benedettini, P. Marelli, M. L. Ciompi, G. Pasero et M. Campa. « Polyclonal B cell activation in ankylosing spondylitis. » Annals of the Rheumatic Diseases 49, n^o 6 (1 juin 1990) : 396–99. http://dx.doi.org/10.1136/ard.49.6.396.

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Granholm, Norman A., et Tito Cavallo. « Autoimmunity, Polyclonal B-Cell Activation and Infection ». Lupus 1, n^o 2 (février 1992) : 63–74. http://dx.doi.org/10.1177/096120339200100203.

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Burg, Debra L., et Thomas L. Feldbush. « Polyclonal activation of primed rat B cells ». Cellular Immunology 98, n^o 2 (avril 1986) : 351–63. http://dx.doi.org/10.1016/0008-8749(86)90295-9.

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Neveu, P. J., et D. Perdoux. « Polyclonal Activation of Guinea Pig Spleen Lymphocytes ». International Archives of Allergy and Immunology 78, n^o 4 (1985) : 401–5. http://dx.doi.org/10.1159/000233921.

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Donati, Daria, Li Ping Zhang, Qijun Chen, Arnaud Chêne, Kirsten Flick, Maja Nyström, Mats Wahlgren et Maria Teresa Bejarano. « Identification of a Polyclonal B-Cell Activator in Plasmodium falciparum ». Infection and Immunity 72, n^o 9 (septembre 2004) : 5412–18. http://dx.doi.org/10.1128/iai.72.9.5412-5418.2004.

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ABSTRACT Polyclonal B-cell activation and hypergammaglobulinemia are prominent features of human malaria. We report here that Plasmodium falciparum-infected erythrocytes directly adhere to and activate peripheral blood B cells from nonimmune donors. The infected erythrocytes employ the cysteine-rich interdomain region 1α (CIDR1α) of P. falciparum erythrocyte membrane protein 1 (PfEMP1) to interact with the B cells. Stimulation with recombinant CIDR1α induces proliferation, an increase in B-cell size, expression of activation molecules, and secretion of immunoglobulins (immunoglobulin M) and cytokines (tumor necrosis factor alpha and interleukin-6). Furthermore, CIDR1α binds to Fab and Fc fragments of human immunoglobulins and to immunoglobulins purified from the sera of different animal species. This binding pattern is similar to that of the polyclonal B-cell activator Staphylococcus aureus protein A. Our findings shed light on the understanding of the molecular basis of polyclonal B-cell activation during malaria infections. The results suggest that the var gene family encoding PfEMP1 has evolved not only to mediate the sequestration of infected erythrocytes but also to manipulate the immune system to enhance the survival of the parasite.

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Correa, Arturo Ramon Vargas, Ana Carolina Egypto Rosa Berbel, Michelle Premazzi Papa, Ana Theresa Silveira de Morais, Ligia Maria Torres Peçanha et Luciana Barros de Arruda. « Dengue Virus Directly Stimulates Polyclonal B Cell Activation ». PLOS ONE 10, n^o 12 (10 décembre 2015) : e0143391. http://dx.doi.org/10.1371/journal.pone.0143391.

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Axelrod, David A. « Polyclonal B-cell activation of rabbit Peyer's patch ». Clinical Immunology and Immunopathology 36, n^o 3 (septembre 1985) : 371–77. http://dx.doi.org/10.1016/0090-1229(85)90057-1.

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Silverstein, Arthur M., et Noel R. Rose. « On the implications of polyclonal B cell activation ». Nature Immunology 4, n^o 10 (1 octobre 2003) : 931–32. http://dx.doi.org/10.1038/ni1003-931.

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HYYPIÄ, T., J. ESKOLA, M. LAINE, A. SALMI et O. MEURMAN. « Polyclonal Activation of B Cells during Rubella Infection ». Scandinavian Journal of Immunology 21, n^o 6 (29 juin 2006) : 615–17. http://dx.doi.org/10.1111/j.1365-3083.1985.tb01852.x.

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Klinman, D. M., et A. D. Steinberg. « Systemic autoimmune disease arises from polyclonal B cell activation. » Journal of Experimental Medicine 165, n^o 6 (1 juin 1987) : 1755–60. http://dx.doi.org/10.1084/jem.165.6.1755.

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The number of B cells producing antibodies reactive with any of seven autoantigens or two conventional antigens was compared at the single-cell level to the total number of Ig-secreting B cells present in the spleens of NZB, MRL lpr/lpr, and BXSB autoimmune mice. The proportion of lymphocytes producing antibodies of each specificity, expressed as a percentage of the total B cell repertoire, was virtually identical among autoimmune and congenic nonautoimmune animals. Furthermore, B cells and serum antibodies reactive with conventional antigens increased commensurately with those reactive with autoantigens. These results indicate that systemic autoimmune diseases arise from polyclonal B cell activation.

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Bonnefoy-Berard, N., C. Vincent, B. Verrier et J. P. Revillard. « Monocyte-independent T-cell activation by polyclonal antithymocyte globulins ». Cellular Immunology 143, n^o 2 (septembre 1992) : 272–83. http://dx.doi.org/10.1016/0008-8749(92)90025-k.

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Tran, Kimvan, Julie Clor et Kamala Tyagarajan. « Kinetics of lymphocyte activation in cytokine expression studies (P6317) ». Journal of Immunology 190, n^o 1_Supplement (1 mai 2013) : 184.20. http://dx.doi.org/10.4049/jimmunol.190.supp.184.20.

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Abstract Activation of lymphocytes leads to expression of cytokine receptors, cytokine secretion and the expression of specific cell surface molecules resulting in divergent immune responses. Correlation of cell surface activation with cytokine secretion levels can provide valuable information to evaluate secretion levels. In this study, we demonstrate the kinetics of CD69 and CD25 expression on human peripheral blood lymphocytes from multiple donors following activation with polyclonal activator, phytohaemagglutinin or phorbol myristate acetate and Ionomycin. The studies were performed using novel no-wash assays on the Muse™ Cell analyzer to assess CD69 and CD25 levels on total lymphocytes. Our data shows that the kinetics of CD69 and CD25 expression demonstrates that a high level of lymphocytes depict CD69 expression as early as 6 hours of stimulation, peaked at 24 hours and down regulated after 48 hours. The observed CD25 expression on lymphocytes was significantly less than that of CD69 at 6 hours, increased at 24 hours and peaked at 48 hours with differences between PHA and PMA-ionomycin activation with some variability in extent of activation between donors. Comparison of the level of cytokines secreted and lymphocyte activation will be presented. The combined measurements of activation markers at the cellular level and the secreted cytokines can provide a comprehensive analysis in monitoring lymphocyte response to polyclonal stimuli.

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Merino, R., M. Iwamoto, L. Fossati et S. Izui. « Polyclonal B cell activation arises from different mechanisms in lupus-prone (NZB x NZW)F1 and MRL/MpJ-lpr/lpr mice. » Journal of Immunology 151, n^o 11 (1 décembre 1993) : 6509–16. http://dx.doi.org/10.4049/jimmunol.151.11.6509.

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Abstract The polyclonal B cell activation is the earliest and most common immunologic abnormality in lupus-prone mice. However, its cellular mechanism(s) has not been well defined. To determine the contribution of CD4+ T cells in this immunologic abnormality, we have depleted CD4+ T cells in lupus-prone (NZB x NZW)F1 and MRL/MpJ-lpr/lpr mice by treating them with anti-CD4 mAb from birth and determined the development of IgM and IgG polyclonal antibody formation. Our results indicate that first, different mechanisms control the development of IgM polyclonal B cell activation in these two autoimmune mice; in (NZB x NZW)F1 mice, IgM polyclonal B cell activation is likely to be a result of an intrinsic B cell defect, whereas CD4+ T cells seem to be responsible for this immunologic abnormality in MRL/MpJ-lpr/lpr mice. Second, the increased production of IgG antibodies, including the IgG3 subclass, was totally regulated by CD4+ T cells in both autoimmune mice. Because IgG3 antibodies can be highly nephritogenic, independent of their immunologic specificities, which is the result of the antibodies' cryoglobulin activity, the active role of CD4+ T cells in the production of IgG3 antibodies in lupus-prone autoimmune mice further strengthens the implication of CD4+ T cells in murine systemic lupus erythematosus.

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Lopes, L. M., M. A. C. Pereira, S. E. Gerken et N. Vaz. « Polyclonal activation of B lymphocytes during experimental infection with Schistosoma mansoni ». Parasitology 100, n^o 1 (février 1990) : 83–91. http://dx.doi.org/10.1017/s0031182000060145.

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SummaryA significant polyclonal activation of B lymphocytes was observed during experimental infection of C57BL/10J mice with Schistosoma mansoni. The isotypic pattern of this expansion, assessed by the Protein-A plaque-forming cell method, was compared with and found to differ from those occurring after infection by Trypanosoma cruzi or injection of bacterial LPS. In the infection of S. mansoni an early expansion of most immunoglobulin isotypes occurs together with a late, sustained expansion of IgG1-secreting cells. High levels of polyclonal B cell activation were observed after adoptive transfer of spleen cells from infected mice to isogenic recipients pre-treated with hydroxyurea.

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Peacock, J. S., T. R. Londo, D. A. Roess et B. G. Barisas. « Biologic activity of antigen receptors artificially incorporated onto B lymphocytes. » Journal of Immunology 137, n^o 6 (15 septembre 1986) : 1916–23. http://dx.doi.org/10.4049/jimmunol.137.6.1916.

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Abstract We describe a method for incorporating monoclonal antibody molecules onto viable murine lymphocytes and summarize the biologic activity of these artificial receptors on B cells. Mouse spleen cells incubated overnight with palmitate conjugates of a monoclonal anti-DNP IgA (protein 315) in the presence of deoxycholic acid incorporate about 50,000 antibody molecules per cell. When concentrations of deoxycholate and palmitoyl-protein 315 are carefully controlled, this labeling procedure does not affect the viability or the normal functions of the receptor-decorated cells. The incorporated antibody specifically binds DNP-antigens, although it appears to be unable to communicate directly with internal cellular components. Yet when these receptor-decorated, unprimed cells are challenged with any one of several DNP-antigens, up to 42,000 per 10(6) B cells differentiate into Ig-secreting cells. This response is about 23-fold greater than that induced in normal cell cultures and is of the same magnitude as that induced by the polyclonal B cell activator LPS. This, in addition to the observation that only about 3.6% of receptor-decorated B cells responding to DNP-conjugated polymerized flagellin (DNP-POL) produce hapten-specific antibody, demonstrates that these antigens cause polyclonal B cell differentiation. Normal spleen cells in the presence of DNP-POL and irradiated spleen cells bearing the artificial receptors do not exhibit the polyclonal antibody response. Also, the response of receptor-decorated B cell is blocked by high but nontoxic concentrations of the nonimmunogenic hapten DNP-lysine. These observations demonstrate that the polyclonal B cell response in this system requires the binding of antigen to artificial receptors on functionally viable cells. The polyclonal B cell response to a thymus-dependent antigen DNP-conjugated bovine gamma-globulin (DNP-BGG) requires the presence of the carrier-primed T cells. On the other hand, T cell depletion by anti-Thy-1.2 monoclonal antibody and complement causes only a slight reduction in the number of receptor-decorated B cells that respond to the relatively thymus-independent antigen DNP-POL. This type of phenomenon is also seen with natural antigen-specific B cells. Thus, polyclonal activation of receptor-decorated B cells exhibits the same gross helper cell requirements as antigenic activation of natural antigen-specific B cells. The results of this study are discussed in the context of the role of membrane-bound surface Ig in antigen-dependent B cell activation.(ABSTRACT TRUNCATED AT 400 WORDS)

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Blutt, Sarah E., Sue E. Crawford, Kelly L. Warfield, Dorothy E. Lewis, Mary K. Estes et Margaret E. Conner. « The VP7 Outer Capsid Protein of Rotavirus Induces Polyclonal B-Cell Activation ». Journal of Virology 78, n^o 13 (1 juillet 2004) : 6974–81. http://dx.doi.org/10.1128/jvi.78.13.6974-6981.2004.

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ABSTRACT The early response to a homologous rotavirus infection in mice includes a T-cell-independent increase in the number of activated B lymphocytes in the Peyer's patches. The mechanism of this activation has not been previously determined. Since rotavirus has a repetitively arranged triple-layered capsid and repetitively arranged antigens can induce activation of B cells, one or more of the capsid proteins could be responsible for the initial activation of B cells during infection. To address this question, we assessed the ability of rotavirus and virus-like particles to induce B-cell activation in vivo and in vitro. Using infectious rotavirus, inactivated rotavirus, noninfectious but replication-competent virus, and virus-like particles, we determined that neither infectivity nor RNA was necessary for B-cell activation but the presence of the rotavirus outer capsid protein, VP7, was sufficient for murine B-cell activation. Preincubation of the virus with neutralizing VP7 antibodies inhibited B-cell activation. Polymyxin B treatment and boiling of the virus preparation were performed, which ruled out possible lipopolysaccharide contamination as the source of activation and confirmed that the structural conformation of VP7 is important for B-cell activation. These findings indicate that the structure and conformation of the outer capsid protein, VP7, initiate intestinal B-cell activation during rotavirus infection.

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Montes, C. L., E. I. Zuñiga, J. Vazquez, C. Arce et A. Gruppi. « Trypanosoma cruzi mitochondrial malate dehydrogenase triggers polyclonal B-cell activation ». Clinical & ; Experimental Immunology 127, n^o 1 (janvier 2002) : 27–36. http://dx.doi.org/10.1046/j.1365-2249.2002.01746.x.

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Coutelier, J. P., P. G. Coulie, P. Wauters, H. Heremans et J. T. van der Logt. « In vivo polyclonal B-lymphocyte activation elicited by murine viruses. » Journal of Virology 64, n^o 11 (1990) : 5383–88. http://dx.doi.org/10.1128/jvi.64.11.5383-5388.1990.

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Ruiz, Blanca H., et Roger E. Carvajal. « Immunomodulation by Histoplasma capsulatum products ; polyclonal activation and mitogenic effects ». Mycopathologia 93, n^o 2 (février 1986) : 113–19. http://dx.doi.org/10.1007/bf00437743.

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Sopori, Mohan L., Yvonne L. Hurt, Susamma Cherian, Alan M. Kaplan et Tiber Diamantstein. « Differential requirement for accessory cells in polyclonal T-cell activation ». Cellular Immunology 105, n^o 1 (mars 1987) : 174–86. http://dx.doi.org/10.1016/0008-8749(87)90066-9.

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Gross, W. L. « Polyclonal B-cell activation by bacteria that induce nonsuppurative sequelae ». Rheumatology International 9, n^o 3-5 (novembre 1989) : 205–11. http://dx.doi.org/10.1007/bf00271882.

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Hunziker, Lukas, Mike Recher, Andrew J. Macpherson, Hans Hengartner et Rolf M. Zinkernagel. « Reply to 'On the implications of polyclonal B cell activation' ». Nature Immunology 4, n^o 10 (1 octobre 2003) : 932. http://dx.doi.org/10.1038/ni1003-932.

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Yui, Mary A., et Stephen L. Kaattari. « Vibrioanguillarum antigen stimulates mitogenesis and polyclonal activation of salmonid lymphocytes ». Developmental & ; Comparative Immunology 11, n^o 3 (juin 1987) : 539–49. http://dx.doi.org/10.1016/0145-305x(87)90043-7.

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Furukawa, F., G. Ohshio et Y. Hamashima. « Possible polyclonal B cell activation in mucocutaneous lymph node syndrome ». European Journal of Pediatrics 145, n^o 1-2 (avril 1986) : 104–8. http://dx.doi.org/10.1007/bf00441867.

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Schnyder, B., E. Weber, W. Fierz et A. Fontana. « On the role of astrocytes in polyclonal T cell activation ». Journal of Neuroimmunology 10, n^o 3 (janvier 1986) : 209–18. http://dx.doi.org/10.1016/0165-5728(86)90103-7.

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Prokešová, L., J. Julák, M. Nováková, M. Pospíšil et M. Mára. « Polyclonal activation of human lymphocytes byBacillus firmus and its constituents ». Folia Microbiologica 40, n^o 6 (décembre 1995) : 647–51. http://dx.doi.org/10.1007/bf02818523.

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Goroff, D. K., J. M. Holmes, H. Bazin, F. Nisol et F. D. Finkelman. « Polyclonal activation of the murine immune system by an antibody to IgD. XI. Contribution of membrane IgD cross-linking to the generation of an in vivo polyclonal antibody response. » Journal of Immunology 146, n^o 1 (1 janvier 1991) : 18–25. http://dx.doi.org/10.4049/jimmunol.146.1.18.

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Abstract The injection of mice with a foreign, polyclonal antibody to IgD sequentially induces: 1) activation of B cells by cross-linking of their cell membrane (m) IgD; 2) B cell processing and presentation of the bound anti-IgD antibody to T cells; 3) activation of these T cells; and 4) T-dependent stimulation of B cell differentiation into IgG1 secreting cells. To determine whether the cross-linking of B cell membrane IgD and/or the resulting B cell activation that follows contribute to the generation of the polyclonal IgG1 response, we examined the abilities of three sets of anti-delta mAb or mAb fragments to stimulate polyclonal IgG1 production. Within each set mAb were matched for species and Ig isotypic determinants, but differed in avidity for IgD or in ability to cross-link IgD. In addition, experiments were performed to determine whether the anti-delta mAb had to be foreign to the immunized mouse to stimulate an IgG1 response. Results of these experiments indicate that: 1) recognition of the injected anti-delta antibody as foreign is required for the induction of a polyclonal IgG1 response; 2) the cross-linking of B cell membrane Ig, which directly activates B cells, can contribute considerably to the generation of in vivo IgG1 production; and 3) that even relatively weak cross-linking of membrane Ig by ligands that bind it with low avidity can make this contribution.

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Adib-Conquy, Minou, Stratis Avrameas et Therese Ternynck. « Monoclonal IgG and IgM autoantibodies obtained after polyclonal activation, show reactivities similar to those of polyclonal natural autoantibodies ». Molecular Immunology 30, n^o 2 (février 1993) : 119–27. http://dx.doi.org/10.1016/0161-5890(93)90083-n.

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Papasavvas, Ioannis, Béatrice Gehrig et Carl P. Herbort. « The Comparative Value of Serum Angiotensin Converting Enzyme (ACE) and Lysozyme and the Use of Polyclonal Antibody Activation in the Work-up of Ocular Sarcoidosis ». Diagnostics 11, n^o 4 (29 mars 2021) : 608. http://dx.doi.org/10.3390/diagnostics11040608.

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Background: The diagnosis of ocular sarcoidosis (OS) is difficult to establish in the absence of manifest systemic involvement. To help clinicians reach a diagnosis, we convened a group of experts in 2006 (International Workshop on Ocular Sarcoidosis (IWOS)) to set-up clinical criteria for the diagnosis of ocular sarcoidosis. In addition, laboratory investigational tests represent a much-needed adjunct to ascertain the diagnosis. However, many of these tests have low sensitivity and specificity. Purpose: The aim of our study was to evaluate the usefulness of serum ACE, serum lysozyme and polyclonal antibody activation in the diagnosis of ocular sarcoidosis and compare the frequency of increased serum levels of lysozyme and ACE in proven ocular sarcoidosis or in suspected ocular sarcoidosis. Methods: Serum ACE and lysozyme were assessed in these two groups and their means compared to a group of non-granulomatous (i.e., non-sarcoidosis) uveitis patients. The proportion of elevated serum ACE versus lysozyme was compared in the sarcoidosis patients. Polyclonal antibody activation was measured by establishing exposition of patients to four human commensal herpesviruses (EBV, CMV, HSV and VZV) using ELISA or immunofluorescence and in parallel by performing quantitative complement fixation (CF) serologies. The ratio of elevated CF to positive ELISA/immunofluorescence serologies was calculated. The mean of ratios (polyclonal antibody activation) was compared between ocular sarcoidosis and control groups. Results: Thirty-seven patients (F24/M13) were included in our study including 17 patients with IWOS Level 1 and 2 criteria qualifying for Group 1 (proven sarcoidosis) and 20 ocular sarcoidosis suspect patients. Mean age was 54.52 ± 23.74. Mean serum levels of ACE was 49.17± 29 IU/L in the ocular sarcoidosis group versus 27.4 ± 15.34 IU/L (p ≤ 0.00018, student’s t test) in the control group. Mean serum lysozyme levels was 39.92 ± 55.5 mg/L in the ocular sarcoidosis group versus 10.5 ± 5.8 mg/L (p ≤ 0.0013) in the control group (n = 30). Both tests were elevated in 8/37 (21.6%) patients, elevated ACE and normal lysozyme was noted in 2/37 (5.4%) patients, whereas the proportion of normal ACE/elevated lysozyme was much higher, 23/37 (62.2%). In 4/37 (10.8%) patients, both tests were normal. The mean score of polyclonal activation (N of elevated CF serologies divided by number of viruses to which a patient was exposed) was 0.6 ± 0.33 in the ocular sarcoidosis group versus 0.15 ± 0.2 for the control group (n = 42) (p ≤ 0.00001). Sensitivity and specificity of ACE and lysozyme were, respectively, 27%/96.6% and 83.7%/90%. Sensitivity and specificity of polyclonal antibody activation amounted to 70%/90.4% Conclusion: Lysozyme was found to be much more useful than ACE as a laboratory test to support the diagnosis of ocular sarcoidosis. As shown in a previous study, polyclonal antibody activation appears to be another useful laboratory test supportive of the diagnosis of ocular sarcoidosis.

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Sanyal, Mrinmoy, Rosemary Fernandez et Shoshana Levy. « Critical Role for CD81 in B Cell Activation. » Blood 110, n^o 11 (16 novembre 2007) : 1342. http://dx.doi.org/10.1182/blood.v110.11.1342.1342.

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Abstract CD81 is a component of the CD19/CD21 signaling complex in B cells. CD81 was originally discovered as target of an anti-proliferative antibody in a human B cell lymphoma. However, the exact role of CD81 in B cell function is not known. Here we studied B cells from CD81 knockout mice. We demonstrate that upon BCR induction these B cells flux higher intracellular free calcium ion; increase the phosphorylation of BCR-related proximal and distal substrates and increase their proliferation. Similarly, polyclonal activation of CD81-deficient B cells with LPS induced increased proliferation and antibody secretion. Consistent with these intrinsic B cell capabilities, CD81-deficient mice mounted significantly higher immune response upon antigenic stimulation. In addition, bone marrow perisinusoidal B cells (IgM+IgD+) capable of mounting T-independent immune responses against blood-borne pathogens were over represented in CD81-deficient mice. These cells also displayed increased calcium influx kinetics as splenic B cells and produced higher amounts of antibody after polyclonal stimulation. Taken together, these results suggest that CD81 is involved in suppressing B cell activation.

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Lampe, M. A., R. Patarca, M. V. Iregui et H. Cantor. « Polyclonal B cell activation by the Eta-1 cytokine and the development of systemic autoimmune disease. » Journal of Immunology 147, n^o 9 (1 novembre 1991) : 2902–6. http://dx.doi.org/10.4049/jimmunol.147.9.2902.

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Abstract Studies of systemic autoimmune disease have led to the view that initiation and progression of the disease process reflects chronic and sustained B cell activation by unidentified polyclonal activating agents. In earlier studies, we found that T cells from MRL/1 mice, which develop murine lupus, express very high levels of a newly defined T cell cytokine, Eta-1. Inasmuch as chronic and sustained B cell stimulation by T cells is a cardinal feature of MRL/1 disease, we determined the effects of this cytokine on Ig production by B cells. We show that both recombinant and biochemically purified natural Eta-1 stimulate IgM and IgG production by mixtures of B cells and macrophages from the autoimmune MRL/l strain. Additional studies suggest that optimal Ig production by Eta-1 may require macrophages and reflect enhanced Ig production by large B cells. These findings support the view that elevated levels of endogenous Eta-1 may cause chronic and sustained polyclonal B cell activation that leads to autoimmune disease in this murine model.

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Richardson, Jennifer, Sophie Broche, Sandrine Baud, Thierry Leste-Lasserre, Françoise Féménia, Daniel Levy, Anne Moraillon, Gianfranco Pancino et Pierre Sonigo. « Lymphoid activation : a confounding factor in AIDS vaccine development ? » Journal of General Virology 83, n^o 10 (1 octobre 2002) : 2515–21. http://dx.doi.org/10.1099/0022-1317-83-10-2515.

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In a previous vaccination trial, inoculation of env gene DNA failed to elicit a detectable antibody response, yet accelerated virus dissemination in most immunized cats following challenge with feline immunodeficiency virus. This result raised the possibility that cell-mediated immune responses had given rise to immune-mediated enhancement of infection. Since high-level replication of immunodeficiency viruses in lymphocytes requires cellular activation, antigen-specific responses or non-specific polyclonal activation may have increased the frequency of optimal target cells. In the present DNA vaccination trial, although designed so as to minimize non-specific polyclonal activation, immune-mediated enhancement was nonetheless observed in certain immunized cats. Moreover, rapid virus dissemination in vivo was associated with the presence of T-helper responses prior to challenge, and was linked to increased susceptibility of lymphocytes to ex vivo infection. Immune activation may thus be a confounding factor in vaccination against lentivirus infection, diminishing vaccine efficacy and giving rise to immune-mediated enhancement.

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Merion, Robert M., Terese Howell et Jonathan S. Bromberg. « PARTIAL T-CELL ACTIVATION AND ANERGY INDUCTION BY POLYCLONAL ANTITHYMOCYTE GLOBULIN1,2 ». Transplantation 65, n^o 11 (juin 1998) : 1481–89. http://dx.doi.org/10.1097/00007890-199806150-00013.

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Book, B., M. Pescovitz, S. Leapman et R. Filo. « Polyclonal Antilymphocyte Sera Induce Immune Activation in Human Renal Allograft Recipients ». Transplantation Proceedings 30, n^o 4 (juin 1998) : 1348–50. http://dx.doi.org/10.1016/s0041-1345(98)00271-1.

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Reina-San-Martı́n, B., A. Cosson et P. Minoprio. « Lymphocyte Polyclonal Activation : A Pitfall for Vaccine Design against Infectious Agents ». Parasitology Today 16, n^o 2 (février 2000) : 62–67. http://dx.doi.org/10.1016/s0169-4758(99)01591-4.

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Dziarski, Roman. « Polyclonal B-cell activation in SLE : Frequencies of autoantibody secreting cells ». Clinical Immunology Newsletter 6, n^o 6 (juin 1985) : 89–93. http://dx.doi.org/10.1016/s0197-1859(85)80027-3.

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Lardans, V., C. Godfraind, J. T. M. van der Logt, F. W. A. Heessen, M. D. Gonzalez et J. P. Coutelier. « Polyclonal B lymphocyte activation induced by mouse hepatitis virus A59 infection ». Journal of General Virology 77, n^o 5 (1 mai 1996) : 1005–9. http://dx.doi.org/10.1099/0022-1317-77-5-1005.

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Takai, Akihiko, Yoshiya Sato et Masamitsu Otsuru. « Polyclonal B cell activation during the course of Angiostrongylus cantonensis infection ». Developmental & ; Comparative Immunology 9, n^o 3 (juin 1985) : 485–95. http://dx.doi.org/10.1016/0145-305x(85)90011-4.

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Nakajima, K., O. Martínez-Maza, T. Hirano, E. C. Breen, P. G. Nishanian, J. F. Salazar-Gonzalez, J. L. Fahey et T. Kishimoto. « Induction of IL-6 (B cell stimulatory factor-2/IFN-beta 2) production by HIV. » Journal of Immunology 142, n^o 2 (15 janvier 1989) : 531–36. http://dx.doi.org/10.4049/jimmunol.142.2.531.

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Abstract Polyclonal B cell activation is commonly observed in AIDS and in infection with HIV. The effect of HIV on the induction of B cell stimulatory factor 2 (BSF-2) production was examined, since BSF-2 plays an essential role in the differentiation of activated B cells to Ig-secreting cells. Increased BSF-2 mRNA levels and increased BSF-2 secretion were observed soon after exposure of mononuclear cells isolated from healthy donors to both "live" and inactivated HIV. HIV-induced BSF-2 production was seen in monocyte/macrophages, but not in T cells. These results suggest that the HIV-induced overproduction of BSF-2 might contribute to the polyclonal B cell activation seen in AIDS and in infection with HIV.

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Pease, Larry R., Matthew C. Guttormson, Christopher A. Parks, Sara J. Felts, Virginia P. Van Keulen, Sarah A. Castro, Laura Evgin, Richard G. Vile et Michael A. Barry. « CAR T cells generated in situ using gene therapy in naturally activated lymph node T cells ». Journal of Immunology 204, n^o 1_Supplement (1 mai 2020) : 246.21. http://dx.doi.org/10.4049/jimmunol.204.supp.246.21.

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Abstract T cells expressing chimeric antigen receptors (CAR T cells) are manufactured outside the body using non-physiological activation and in vitro culture protocols. The procedure takes 3 weeks and costs approximately $450,000 to administer. We have devised a scheme using mouse models for manufacturing CAR T cells in just 3 days employing a natural, polyclonal anti-viral immune response inside a lymph node (LN) using off the shelf reagents that can be applied widely in populations. CAR T cells emerge from the LN within a week, invade solid tumor, and eliminate the targeted antigen-positive tumor cells. Polyclonal activation of T cells is achieved by modifying the antigen presenting properties of lymph node resident professional antigen presenting cells (APC) through viral expression of allogeneic major histocompatibility antigens. The ensuing polyclonal activation occurs in the context of virus activated APC within the normal aarchitecture of the LN and confers robust T cell activation signals directing the development of cytolytic T cells. During the course of T cell activation, the T cells are transduced in situ with retroviruses encoding selected CARs. This approach could be applied to any number of different CARs to target a variety of tumors. T cells activated in the lymph node are functionally distinct from those activated using standard CAR T manufacturing protocols. We anticipate that CAR T cells generated in situ to natural stimuli will exhibit more normal immune regulatory properties that will impact their therapeutic utility. Because our approach uses off the shelf reagents and is administered using standard clinical procedures, cost to patients should be lowered and access to therapy increased.

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Plagemann, Peter G. W., Quentin A. Jones et William A. Cafruny. « N-Glycans on the short ectodomain of the primary envelope glycoprotein play a major role in the polyclonal activation of B cells by lactate dehydrogenase-elevating virus ». Journal of General Virology 81, n^o 9 (1 septembre 2000) : 2167–75. http://dx.doi.org/10.1099/0022-1317-81-9-2167.

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The common biologically cloned isolates of lactate dehydrogenase-elevating virus (LDV-P and LDV-vx) invariably cause a polyclonal activation of B cells in immunocompetent mice. It is recognized by an at least 10-fold increase in plasma IgG2a levels and the de novo formation of immune complexes that most likely consist of autoantibodies and their antigens. The present study indicates that three closely spaced N-glycans on the short ectodomain of the primary envelope glycoprotein, VP-3P, of LDV-P/vx, play a major role in inducing the polyclonal proliferation of B cells. IFN-γ then seems to mediate the differentiation of the activated B cells to IgG2a-producing plasma cells. These conclusions are based on the finding that the IgG2a hypergammaglobulinaemia and immune complex formation were much lower in mice that were infected with LDV variants (LDV-C and LDV-v) whose VP-3P ectodomains lack two of the three N-glycans than in LDV-P/vx infected mice. In contrast, the VP-3P ectodomains of three neutralization escape variants of LDV-C/v whose VP-3P ectodomains possess three N-glycosylation sites caused a polyclonal activation of B cells comparable to that of LDV-P/vx.

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Bessler, W. G., M. Cox, A. Lex, B. Suhr, K. H. Wiesmüller et G. Jung. « Synthetic lipopeptide analogs of bacterial lipoprotein are potent polyclonal activators for murine B lymphocytes. » Journal of Immunology 135, n^o 3 (1 septembre 1985) : 1900–1905. http://dx.doi.org/10.4049/jimmunol.135.3.1900.

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Abstract The lipoprotein from the outer membrane of Escherichia coli and other Enterobacteriaceae is a potent polyclonal activator for B lymphocytes. To determine the molecular structure responsible for the biologic activity of lipoprotein, a well-defined series of analogs of its N-terminal part was synthesized: S-(2,3-bis(palmitoyloxy)-(2-RS)-propyl)-N-palmitoyl-(R)-cysteine, -cysteine methyl ester, -cysteinyl-serine, -cysteinyl-seryl-serine, -cysteinyl-seryl-seryl-asparagine, and -cysteinyl-seryl-seryl-asparaginyl-alanine. All compounds were tested for mitogenic activity toward spleen cells from BALB/c, LPS-non-responder C3H/HeJ, and congenitally athymic C3H/Tif/Bom/nu/nu mice, measuring the incorporation of [3H]thymidine into DNA. Lymphocyte activation was confirmed by determination of the incorporation of [3H]uridine into RNA and [3H]leucine into protein. The synthetic lipopeptides were also investigated for their ability to stimulate B lymphocytes into immunoglobulin secretion, as shown by a hemolytic plaque assay. Throughout our studies, the compounds carrying two to five amino acids exhibited strong stimulation activity toward B lymphocytes comparable to native lipoprotein. In contrast, products containing only one amino acid, cysteine or cysteine methyl ester, were only marginally active, indicating that to obtain full biologic activity the presence of the hydrophilic dipeptide structure is necessary. All compounds exhibited only a marginal effect on thymocytes. Thus, a series of defined synthetic fragments of a bacterial outer membrane component exhibits a pronounced mitogenic and polyclonally stimulating activity towards B lymphocytes. The substances will be valuable tools for more detailed investigations on the molecular mechanisms of B cell activation.

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Li, Jun, Kenrick Semple, Kane Koasaard, Kelley M. K. Haarberg, Fang-ping Chen, Claudio Anasetti et Xue-Zhong Yu. « Prevention of Graft-Versus-Host Disease by HY-Specific Induced Tregs Through Activation-Dependent Manner »,. Blood 118, n^o 21 (18 novembre 2011) : 4023. http://dx.doi.org/10.1182/blood.v118.21.4023.4023.

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Abstract Abstract 4023 Naturally occurring regulatory T cells (nTregs) may prevent graft-versus-host disease (GVHD) while preserving graft-versus-leukemia (GVL) activity. However, clinical application of nTregs has been severely hampered by their scarce availability and non-selective suppression. To overcome these limitations, we took the alternative approach to induce antigen-specific Tregs (iTregs) and tested their efficacy and selectivity in the prevention of GVHD in a pre-clinical model of bone marrow transplantation (BMT). We selected HY as target antigen, because it is a naturally processed and ubiquitously expressed minor histocompatibility antigen (miHAg) with a proven role in GVHD and GVL effect. To generate HY-specific iTregs, naïve CD4+CD25− cells were isolated from MHC II-restricted, HY-specific transgenic and Foxp3/GFP knock-in mice, and were stimulated with HY peptide and APC, in the presence of TGFb and retinoic acid. Marrow plus polyclonal CD4 T effector cells (Teffs) from B6 donor splenocytes induced GVHD when transplanted into lethally irradiated (B6 x bm12)F1 recipients, and adoptive transfer of HY-specific iTregs (CD4+CD25+GFP+) significantly decreased GVHD mortality in male (HY+) but not female (HY−) recipients. On a per cell basis, HY-specific iTregs were significantly more potent than polyclonal Tregs in the prevention of GVHD. These data indicate that HY-specific iTregs were effective in controlling GVHD in an activation-dependent manner. Because polyclonal Teffs cells recognize bm12 alloantigen whereas iTregs recognize HY miHAg, these data suggest that Tregs may control GVHD through a linked-suppression on Teffs in vivo. Mechanistically, by measuring iTregs and Teffs in spleen and liver of the recipients, we found that HY-specific iTregs expanded extensively and significantly suppressed expansion and infiltration of Teffs in male but not female recipients. We finally generated alloreactive iTregs from polyclonal CD4 precursors, and found that these iTregs highly suppressed the Teffs alloresponse in vitro and in vivo. These results show that Ag-specific iTregs are promising cell therapy for effective GVHD prevention in human allogeneic hematopoietic cell transplantation. Disclosures: No relevant conflicts of interest to declare.

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Hirsch, F., J. Kuhn, M. Ventura, M. C. Vial, G. Fournie et P. Druet. « Autoimmunity induced by HgCl2 in Brown-Norway rats. I. Production of monoclonal antibodies. » Journal of Immunology 136, n^o 9 (1 mai 1986) : 3272–76. http://dx.doi.org/10.4049/jimmunol.136.9.3272.

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Abstract Mercuric chloride (HgCl2) induces in Brown-Norway rats (BN) a B cell polyclonal activation resulting in autoimmune disease. Spleen cells from BN rats injected with HgCl2 were fused with IR983F, a nonsecreting rat myeloma cell line, in order to obtain monoclonal antibodies reacting with autoantigens or IgE-producing hybridomas. After screening for immunoglobulin-producing clones, we found 5% clones with anti-tissue activity, 8% with anti-TNP activity, and 41% secreting IgE. Among the anti-tissue monoclonal antibodies, one recognizes both TNP and mesangial structures of rat normal glomeruli, which could be an as yet unrecognized mechanism of nephrotoxicity. These experiments 1) confirm that HgCl2 induces polyclonal activation, 2) show that the mercury model is of interest to obtain monoclonal IgE and various autoantibodies, and 3) suggest a new possible mechanism of antibody-mediated renal injury.

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Foster, Rachel A., Jennifer Carlring, Michael W. McKendrick, Andrew Lees, Ray Borrow, Robert C. Read et Andrew W. Heath. « Evidence of a Functional B-Cell Immunodeficiency in Adults Who Experience Serogroup C Meningococcal Disease ». Clinical and Vaccine Immunology 16, n^o 5 (11 mars 2009) : 692–98. http://dx.doi.org/10.1128/cvi.00485-08.

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ABSTRACT After adolescence, the incidence of meningococcal disease decreases with age as a result of the cumulative immunizing effect of repeated nasopharyngeal colonization. Nevertheless, some adults succumb to meningococcal disease, so we hypothesized that this is due to a subtle functional immunological defect. Peripheral blood lymphocytes derived from survivors of serogroup C meningococcal disease and from age- and sex-matched controls were incubated with a polyclonal B-cell activator containing anti-immunoglobulin D (α-δ-dex) employed to mimic antigen-specific stimuli encountered during immune responses to bacterial polysaccharides, with and without T-cell activation (using anti-CD3/anti-CD28). Subsequent proliferation and activation of T and B lymphocytes were measured. In patients, T-cell responses to polyclonal stimuli and the delivery of T-cell help to B cells were unimpaired. Levels of B-cell proliferation in response to α-δ-dex stimulation alone were low in all samples but were significantly lower in patients than in controls, and these differences were more pronounced with the addition of T-cell help. The data are consistent with the presence of a subtle immunodeficiency in adults who have exhibited susceptibility to meningococcal disease. This defect is manifested as an impaired B-cell response to T-cell-independent type 2 antigens analogous to bacterial capsular polysaccharide.

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