title: T cell tolerization in vitro: modulation of helper and suppressor cell activities.
abstract: This paper analyzes the conditions for in vitro tolerization of purified whole T cell populations and the consequences on helper and suppressor T cell functions. Highly purified splenic T cells from adult DBA/2 mice were incubated in vitro for 24 hr with high doses of trinitrophenyl coupled to human gamma-globulins (TNP-HGG). A profound inhibition of the TNP-specific helper function of these T lymphocytes was observed in a cooperative culture with normal purified splenic B cells and TNP-SRBC as antigen. This state of specific unresponsiveness was maintained after trypsin treatment of the cells, at the end of the 24-hr incubation with the tolerogen. We checked that this procedure removed the vast majority of F23.1 T cell receptor determinants from the cells. This result indicates that T cell receptors for antigen were not merely blocked by the tolerogen. In addition, B cells preincubated with tolerized T cells for 24 hr remained as responsive to TNP as B cells mixed with normal T cells in similar conditions. This demonstrates that the decreased response is not the result of secondary B cell tolerization. In addition, anti-Ia monoclonal antibodies were shown to block the induction of tolerance. We also showed that tolerized T cells significantly decreased the anti-TNP response of normal T and B cells in vitro, whereas the anti-SRBC response in the same cultures was unaffected. When tolerized T cells were separated into Lyt-2- and Lyt-2+ cells, it was found that tolerized Lyt-2- cells had lost about 75% of their helper activity and that Lyt-2+ cells suppressed 70% of the response of a normal T and B cell culture. Thus, in vitro induction of T cell tolerance results in a specific T cell unresponsiveness which is due to both helper T cell inactivation and induction of specific suppressor T cells.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000950:Antigens, Ly / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D004306:Dose-Response Relationship, Immunologic; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D051379:Mice; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D014301:Trinitrobenzenes / Q000276:immunology; D014357:Trypsin; D005719:gamma-Globulins / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000950:Antigens, Ly; D000949:Histocompatibility Antigens Class II; D014301:Trinitrobenzenes; D005719:gamma-Globulins; D014357:Trypsin