title: Completely allogeneic spleen cells induced cytolytic neonatal tolerance to alloantigens, but failed to establish allo-helper interactions with host T cells.
abstract: The injection of spleen cells from F1 mice into-newborns from a parental strain results in the establishment of cytolytic tolerance to donor alloantigens and the development of a lupus-like disease. This syndrome is the consequence of the recognition by alloreactive host CD4+ T cells of discordant major histocompatibility complex (MHC) class II antigens on semi-allogeneic donor B cells. We have analysed whether completely allogeneic spleen cells are as able as semi-allogeneic spleen cells to induce cytolytic tolerance to donor alloantigens and to co-operate with alloreactive T cells for autoantibody production. BALB/c mice were injected at birth with Thy-1-depleted spleen cells from (C57BL/6 x BALB/c)F1 or C57BL/6 mice, either alone or in combination. Cytolytic tolerance was always induced, as manifested by persistence of chimerism and acceptance of skin allografts. However, only F1 semi-allogeneic B cells were activated by alloreactive host T cells to produce anti-DNA IgG antibody. The deficient co-operation between BALB/c CD4+ T cells and completely allogeneic C57BL/6 B cells was confirmed after neonatal injection of (C57BL/ 6 x BALB/c)F1(Igha) spleen cells together with C57BL/6(Ighb) spleen cells. These mice developed anti-DNA antibodies bearing only the Igha allotype. Similar results were observed in experiments of allogeneic interaction in vitro, in which BALB/c CD4+ T cells were cocultured with either (C57BL/6 x BALB/c)F1 or C57BL/6 B cells. The present results demonstrate that completely allogeneic spleen cells efficiently induced cytolytic unresponsiveness to donor alloantigens, but B cells contained in this spleen cell population were unable to establish allo-helper interactions with alloreactive CD4+ T cells, suggesting that cytolytic and helper T-cell interactions involved in alloreactivity may be different.
authors.affiliation: Hospital Universitario Marqués de Valdecilla, Santander, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Ramos
authors.forename: M
authors.initials: M
authors.lastname: González
authors.forename: M
authors.initials: M
authors.lastname: López-Hoyos
authors.forename: R
authors.initials: R
authors.lastname: Carrió
authors.forename: J
authors.initials: J
authors.lastname: Merino
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001402:B-Lymphocytes / Q000276:immunology* / Q000637:transplantation; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018929:Cell Culture Techniques; D006789:Host vs Graft Reaction / Q000276:immunology; D007108:Immune Tolerance; D007519:Isoantigens / Q000276:immunology*; D008211:Lymphocyte Cooperation / Q000276:immunology*; D017710:Lymphocyte Transfusion; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000276:immunology / Q000637:transplantation*; D014184:Transplantation, Homologous
chemical_list: D007519:Isoantigens