Heterogeneous and monoclonal helper T cells induce similar anti-(4-hydroxy-3-nitrophenyl)acetyl (NP) antibody populations in the primary adoptive response. I. Isotype distribution.
In the response to NP-lipopolysaccharide or NP-Ficoll predominantly anti-NP antibodies of the IgM class are produced in mice with lower amounts of IgG3 and IgG2b but little or no IgG1 and IgG2a. In contrast, in the primary T-dependent response to NP-keyhole limpet hemocyanin (KLH) or NP-chicken gamma globulin high amounts of all IgG isotypes are induced. To investigate whether isotype-specific T cells are responsible for these differences we carried out cell transfer experiments using carrier-specific T cell lines. Two such lines were established and one of the two could be cloned. Upon activation by antigen the T cell lines induced unprimed syngeneic splenic B cells to proliferate and differentiate into antibody-secreting cells in vitro in an antigen-nonspecific way. Antigen-specific activation of unprimed B cells in a cell transfer system in vivo showed that high concentrations of hapten-specific antibodies of all IgG isotypes are induced through both carrier-specific T helper lines. The isotypic pattern of these antibodies is similar to that produced via heterogeneous splenic T cells in the cell transfer system, or in normal animals on immunization with the same antigen. These results suggest that isotype-specific T cells are not required for the production of IgG isotypes in a primary anti-NP response and thus not responsible for the differences seen in isotypic patterns between T-dependent and T-independent responses.
D000818:Animals; D000941:Antigens / Q000008:administration & dosage / Q000276:immunology; D000955:Antigens, T-Independent / Q000008:administration & dosage / Q000276:immunology; D002352:Carrier Proteins / Q000008:administration & dosage / Q000276:immunology; D002999:Clone Cells / Q000276:immunology; D000939:Epitopes / Q000235:genetics; D006433:Hemocyanins; D007116:Immunization, Passive; D007126:Immunoglobulin Allotypes / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D009596:Nitrophenols / Q000008:administration & dosage / Q000276:immunology*; D010648:Phenylacetates; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D000941:Antigens; D000955:Antigens, T-Independent; D002352:Carrier Proteins; D000939:Epitopes; D007126:Immunoglobulin Allotypes; D009596:Nitrophenols; D010648:Phenylacetates; C026242:4-hydroxy-5-nitrophenyl acetic acid; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin