Regulation of immunoglobulin synthesis by human T cell subsets as defined by anti-D44 monoclonal antibody within the CD4+ and CD8+ subpopulations.
In our previous paper, we demonstrated that anti-D44 MAb can, in the presence of complement, eliminate all the allocytotoxicity generated during a mixed lymphocyte reaction without affecting the alloproliferative response. As approximately 70% of CD4+ cells and 30% of CD8+ will be stained with anti-D44 MAb, we researched the functional role of the D44+ and D44- cells in each of these T cell subsets in the PWM-induced antibody response. We found that most of the helper activity for immunoglobulin (Ig) synthesis was mediated by CD4+ D44+ lymphocytes and that virtually all the suppressive activity was mediated by CD8+ D44- lymphocytes. Surprisingly enough, we noticed that the low level of Ig synthesis induced in B cells by CD4+ D44- lymphocytes could be strongly amplified by the addition of radiosensitive CD8+ lymphocytes, suggesting coexisting opposite immunoregulatory functions within the CD8+ T cell subset. These results, together with previous data, indicate that anti-D44 MAb subdivides T cells into subpopulations with distinct functional repertoires: a CD4+ D44+ helper subpopulation, a CD8+ D44+ cytotoxic subpopulation, and a CD8+ D44- suppressor subpopulation.
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D010641:Phenotype; D011043:Pokeweed Mitogens / Q000494:pharmacology; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D007136:Immunoglobulins; D011043:Pokeweed Mitogens