BCG induced CD4+ cytotoxic T cells from BCG vaccinated healthy subjects: relation between cytotoxicity and suppression in vitro.
Mycobacterial antigen specific cytotoxic T cells killing antigen-pulsed antigen presenting cells (APC) were induced from peripheral blood mononuclear cells (PBMC) of BCG-vaccinated healthy subjects after activation in vitro with BCG. CD8+ depleted cells were as effective as PBMC, indicating that CD4+ cells play a dominant role in this phenomenon. CD4+ T cell clones raised against BCG also exhibited mycobacterial antigen specific cytotoxicity and suppressed BCG-driven selfproliferation. However, the same clones could either suppress or enhance the proliferation of other T cell clones from the same subject. The possible function in vivo of the cytotoxicity mediated by CD4+ T cells is discussed.
D000942:Antigens, Bacterial / Q000276:immunology*; D001500:BCG Vaccine / Q000276:immunology*; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D009163:Mycobacterium bovis / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
D000942:Antigens, Bacterial; D001500:BCG Vaccine