title: Inhibitory activity of interleukin B on the suppressor T cell hybrid T2D4.
abstract: Interleukin B (IL-B), a product of unstimulated B cells, is defined by its ability to selectively prevent the differentiation of suppressor T lymphocytes from precursors into effectors. The present study was undertaken to determine whether IL-B could also be active in modulating the activity of the T cell hybrid T2D4, which produces immunoglobulin-binding suppressor factors. T2D4 cells can be selectively induced by incubation with various isotypes of antibody to express isotype-specific Fc receptors and to release soluble factors that suppress production of the corresponding isotype. The data presented here demonstrate that IL-B is greatly effective in inhibiting T2D4 activities. Either pretreatment with IL-B or continuous exposure to IL-B prevents isotype activation of T2D4. As a result, T2D4 cells do not express isotype receptors and do not produce detectable amounts of isotype-specific suppressor factors. This IL-B regulatory activity on T2D4 is temperature dependent and is inhibited by cytochalasin B. These findings provide new insights on the mechanism by which IL-B enhances antibody responses, and they offer a conceptual framework for analyzing IL-B activity on suppressor T cells.
mesh_terms: D000818:Animals; D003571:Cytochalasin B / Q000494:pharmacology; D003864:Depression, Chemical; D005260:Female; D006133:Growth Substances / Q000494:pharmacology*; D006825:Hybridomas / Q000187:drug effects*; D007074:Immunoglobulin G / Q000276:immunology; D007132:Immunoglobulin Isotypes / Q000276:immunology; D015847:Interleukin-4; D008213:Lymphocyte Activation / Q000187:drug effects; D008222:Lymphokines / Q000096:biosynthesis / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D029584:Prostatic Secretory Proteins; D011961:Receptors, Fc / Q000096:biosynthesis; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects* / Q000276:immunology; D013696:Temperature
chemical_list: D006133:Growth Substances; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D008222:Lymphokines; D029584:Prostatic Secretory Proteins; D011961:Receptors, Fc; C043076:beta-microseminoprotein; C013059:immunoglobulin-binding factors; D015847:Interleukin-4; D003571:Cytochalasin B