title: Genetics of resistance to the African trypanosomes. IV. Resistance of radiation chimeras to Trypanosoma rhodesiense infection.
abstract: The cellular bases of resistance to the African trypanosomes were examined in inbred mice. As part of these studies, reciprocal bone marrow cell transplants were performed between H-2 compatible mice which differ in relative resistance to Trypanosoma brucei rhodesiense infection. Survival times, parasitemias and IgM antibody responses to the surface antigen of the infecting variant type were measured in these semiallogeneic bone marrow chimeras. Relatively resistant C57BL/10 mice, intermediate A.By mice, and least resistant C3H.SW mice that were reconstituted after lethal irradiation with syngeneic bone marrow cells displayed resistance and immunity characteristic of the homologous donor strain. When C57BL/10 mice were reconstituted with C3H.SW mouse bone marrow cells they retained the ability to produce antibodies to trypanosome surface antigen but the antibody titers were significantly reduced. Control of parasitemia and mean survival time were reduced in these chimeras, but differed significantly from C3H.SW mice. A.By mice that received cells from C57BL/10 donors exhibited antibody responses and survival times similar to the C57BL/10 mice. Survival times of A.By mice given syngeneic cells or C3H.SW cells were the same, but the antibody responses of A.By mice given C3H.SW cells were lower than those of A.By mice given syngeneic cells. C3H.SW mice reconstituted with C57BL/10 bone marrow cells were capable of making antibodies and controlling parasitemia, in marked contrast to the absence of such responses in C3H.SW mice reconstituted with syngeneic cells. Survival times, however, were indistinguishable from those of C3H.SW mice given syngeneic cells. Thus, resistance to T. b. rhodesiense was shown for the first time to depend on donor bone marrow derived cells as well as upon radiation-resistant cells/factors associated with host genetic background. Also, parasite-specific IgM antibody responses seem to be regulated by a mechanism which does not depend on bone marrow derived cells alone, and the presence of such immune responses is not linked to survival time.
mesh_terms: D000818:Animals; D016026:Bone Marrow Transplantation; D004195:Disease Models, Animal; D007113:Immunity, Innate; D007075:Immunoglobulin M / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D011828:Radiation Chimera; D013045:Species Specificity; D014346:Trypanosoma brucei brucei / Q000276:immunology; D014353:Trypanosomiasis, African / Q000235:genetics / Q000276:immunology* / Q000469:parasitology
chemical_list: D007075:Immunoglobulin M