Regulation of antibody synthesis to sheep red cells in cultures of nu/nu spleen cells by T-cell replacing factor (TRF) and immunoglobulin-binding factor (IBF).
Fc receptor positive alloantigen-activated T cells release an immunoglobulin binding factor (IBF) which suppresses in vitro antibody synthesis. The present work was undertaken to approach the mechanisms by which IBF suppresses the response, and we obtained the following results. First, IBF does not inhibit DNA synthesis in lipopolysaccharide stimulated spleen cells while suppressing the polyclonal plaque response, indicating that IBF does not interfere with B-cell proliferation. Second, antibody synthesis by spleen cells from Nude (nu/nu) mice, stimulated with sheep red blood cells triggered by concanavalin A induced T-cell replacing factor (TRF) was suppressed by IBF, indicating that the factor does not need mature T cells to express its activity. Kinetics experiments showed that IBF does not destroy TRF but rather acts sequentially with the helper factor on the late phase of the differentiation of B cells to antibody producing cells.
D000818:Animals; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation; D002478:Cells, Cultured; D004912:Erythrocytes / Q000276:immunology*; D007108:Immune Tolerance; D007136:Immunoglobulins / Q000378:metabolism; D008213:Lymphocyte Activation; D051379:Mice; D008819:Mice, Nude; D011485:Protein Binding; D012756:Sheep; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
D007136:Immunoglobulins