title: Suppression of BCG cell wall-induced delayed-type hypersensitivity by pretreatment with killed BCG: induction of nonspecific suppressor T cells by the adjuvant portion (MDP) and of specific suppressor T cells by the antigen portion (TAP).
abstract: We showed previously that antigen-nonspecific suppressor T cells induced by i.v. injection of heat-killed bacillus Calmette-Guérin (BCG) were involved in suppression of delayed-type hypersensitivity (DTH). We suggested that the adjuvant portion of BCG might be involved in the induction of these cells. In this report, we show that BCG cell wall-induced DTH responses in mice pretreated with muramyl dipeptide (MDP), a minimum adjuvant constituent of BCG, were suppressed nonspecifically. In addition, we show that pretreatment with tuberculin active peptide (TAP), the antigenic peptide from Mycobacterium tuberculosis, induces antigen-specific suppression of DTH responses. In both instances, suppression was shown to be due to non-adherent cells that act to inhibit elicitation of DTH. Furthermore, using the macrophage migration inhibition assay, an in vitro correlate of DTH, we found that antigen-nonspecific and antigen-specific suppressor T cells were induced by the injection of MDP and TAP, respectively. Thus, suppressor T cells induced by the adjuvant and antigen portions of BCG may act by interfering with the lymphokine-dependent mechanisms by which DTH effector T cells elicit DTH.
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology*; D000818:Animals; D001202:Ascitic Fluid / Q000276:immunology; D001500:BCG Vaccine / Q000494:pharmacology*; D001426:Bacterial Proteins; D002464:Cell Migration Inhibition; D000939:Epitopes; D005260:Female; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D007108:Immune Tolerance; D007116:Immunization, Passive; D008089:Listeria monocytogenes / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D009163:Mycobacterium bovis / Q000276:immunology* / Q000502:physiology; D010455:Peptides / Q000008:administration & dosage / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D014373:Tuberculin / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D001500:BCG Vaccine; D001426:Bacterial Proteins; D000939:Epitopes; D010455:Peptides; D014373:Tuberculin; C009610:tuberculin-active protein, Mycobacterium; D000119:Acetylmuramyl-Alanyl-Isoglutamine