title: Lymphokine-mediated activation of a T cell-dependent IgA antipolysaccharide response.
abstract: Immune responses to bacterial polysaccharides are important to host immunity at mucosal surfaces. We previously showed that BALB/c mice produce substantial T cell-dependent IgA responses to alpha (1,3) glucan determinants on the bacterial capsular polysaccharide dextran B1355. The data in this study demonstrate that the requirement for T cells for the activation of the IgA anti-alpha (1,3) dextran B1355 response can be replaced by T cell-derived nonantigen specific helper factors that appear to act during the late stages of B cell differentiation. Supernatants from the activated T cell lines cr-15 and (DL)C.C3.11.75, which contain interferon and late-acting T cell replacing factor activity, supported terminal differentiation of dextran-stimulated B cells to IgA anti-alpha (1,3) glucan antibody-forming cells and substantially increased IgM anti-alpha (1,3) glucan responses in culture. Although supernatants with interleukin 2 activity did not support optimal antigen-driven plaque-forming cell responses, they synergized with supernatants having interferon and T cell replacing factor activity in the production of IgA and IgM anti-alpha (1,3) glucan responses and IgM anti-SRBC responses. Supernatants from the T cell lines B6.11 and (DL)A.4 contained B cell growth factor activity but did not support activation of IgA anti-alpha (1,3) glucan PFC. These studies suggest that interferon and/or T cell replacing factor play an important role in the antigen-driven differentiation of B cells of the IgA and IgM isotypes to antibody-forming cells.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000921:Antibody-Producing Cells / Q000276:immunology; D000955:Antigens, T-Independent / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D003208:Concanavalin A / Q000502:physiology*; D003911:Dextrans / Q000276:immunology; D006133:Growth Substances / Q000502:physiology; D007070:Immunoglobulin A / Q000096:biosynthesis; D007371:Interferon-gamma / Q000502:physiology; D007376:Interleukin-2 / Q000502:physiology; D015847:Interleukin-4; D015848:Interleukin-5; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D011135:Polysaccharides, Bacterial / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000955:Antigens, T-Independent; D003911:Dextrans; D006133:Growth Substances; D007070:Immunoglobulin A; D007376:Interleukin-2; D015848:Interleukin-5; D008222:Lymphokines; D011135:Polysaccharides, Bacterial; C021649:concanavalin A-induced helper factors; D003208:Concanavalin A; D015847:Interleukin-4; D007371:Interferon-gamma