Immunoregulation of genetically controlled acquired responses to Leishmania donovani infection in mice: demonstration and characterization of suppressor T cells in noncure mice.
On a B10 genetic background, genes in the I region of H-2 influence the development of acquired T-cell mediated immunity to Leishmania donovani infection in mice. In previous studies, noncure in H-2d mice could be abrogated by pretreatments with cyclophosphamide or sublethal irradiation. The prophylactic effect of these pretreatments was consistent with deletion of the precursors of suppressor T cells suppressing T-cell-mediated immune responses. In this study, cell transfer experiments provide direct evidence for the role of suppressor T cells in the noncure response. T-cell-enriched populations isolated from the spleens of B10.D2/n mice infected 30, 61, or 85 days previously reversed the prophylactic effect of sublethal irradiation when injected before infection into B10.D2/n mice that had received 550 rads. B-cell-enriched populations failed to transfer suppression in this manner, and T-cell-enriched populations from the spleens of normal B10.D2/n mice had only a transient effect on liver parasite loads. Transfer of suppression with the T-cell-enriched populations from infected donors was abrogated by pretreatment with anti-Thy-1.2 and anti-Lyt-1.2 antisera plus complement but not by pretreatment with anti-Lyt-2.2 plus complement, indicating that the suppressor T cell involved has an Lyt-1+2- surface phenotype. Results are discussed in relation to the possible mechanism of H-2-linked control.
D000818:Animals; D000954:Antigens, Surface / Q000235:genetics; D001402:B-Lymphocytes / Q000276:immunology; D005260:Female; D006183:H-2 Antigens / Q000235:genetics*; D007111:Immunity, Cellular; D007074:Immunoglobulin G / Q000032:analysis; D007898:Leishmaniasis, Visceral / Q000235:genetics* / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D010641:Phenotype; D013154:Spleen / Q000166:cytology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000637:transplantation; D014916:Whole-Body Irradiation
D000954:Antigens, Surface; D006183:H-2 Antigens; D007074:Immunoglobulin G