CD3+ T cells in severe combined immunodeficiency (scid) mice. IV. Graft‐vs. ‐host resistance of H‐2d scid mice to intravenous injection of allogeneic H‐2b (C57BL/6) spleen cells

Abstract

Intraperitoneal injection of 2 × 10⁷ nonfractionated spleen cells (SC) from C57BL/6 (B6, H‐2^b) mice into completely allogeneic immunodeficient H‐2^d scid mice induced clinical and histological signs of acute graft‐vs.‐host disease (GVHD), with all transplanted severe combined immunodeficiency (scid) mice dying in the 3rd week post‐transfer. In contrast four out of five scid mice survived for > 7 weeks after intravenous (i.v.) injections of equal numbers of B6 SC. Intravenously allotransplanted scid mice analyzed in the 8th week post‐transfer had engrafted donor‐type CD4⁺ and CD8⁺ T cells in the spleens but showed no clinical or histological evidence of GVHD. i.v. injection of 10⁷ or 10^6O B6 SC engrafted allogeneic T cells in spleens of scid recipients; in contrast, i.v. injection of 10⁵ nonfractionated B6 SC or 3 × 10⁵ cell sorter‐purified, naive or anti‐H‐2^d‐primed splenic CD4⁺ or CD8⁺ B6 T cells led to rejection by young scid recipient mice. B6 T cells engrafted into spleens of scid mice after i.v. injection showed proliferative anti‐host alloreactivity in vitro. No cytotoxic reactivity against host‐type alloantigens was found in standard 4‐h ⁵¹Cr‐release assays. These data demonstrate that allogeneic T cells injected i.v. into immunodeficient scid mice are partially tolerized against host‐type alloantigens.