Phenolic glycolipid-I of Mycobacterium leprae induces general suppression of in vitro concanavalin A responses unrelated to leprosy type.
Using a costimulant assay, in vitro Con A responses of patients across the leprosy spectrum were found to be markedly suppressed by phenolic glycolipid-I (PGL-I), a unique antigen of M. leprae. The degree of inducible suppression as well as the number of leprosy patients showing suppression of mitogenic responses was higher with PGL-I as compared with integral M. leprae (p less than 0.05 to less than 0.01). Both untreated lepromatous (60%) as well as tuberculoid leprosy (67%) patients showed significant suppression ranging from 13 to 64% and 12 to 79%, respectively. Thus, PGL-I appears to have a universal suppressive effect on Con A responses and is unlikely to play a central role in determining the leprosy spectrum.
D000942:Antigens, Bacterial / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology; D004306:Dose-Response Relationship, Immunologic; D006017:Glycolipids / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance; D066298:In Vitro Techniques; D007918:Leprosy / Q000276:immunology*; D008213:Lymphocyte Activation; D009166:Mycobacterium leprae / Q000276:immunology*
D000942:Antigens, Bacterial; D006017:Glycolipids; C045169:phenolic glycolipid I, Mycobacterium leprae; D003208:Concanavalin A