Involvement of IL-2Rβ+ T cells in graft-versus-host disease of the liver and intestine across mutant MHC class I or class II barrier

MHC class I mutant B6.C-H-2(bm1) (bm1) mice or MHC class II mutant B6.C-H-2(bm12) (bm12) were sublethally irradiated and received bone marrow (BM) cells from B6 or Thy1.1(+) B10 mice. Most T cells in the liver, spleen and intestine were replaced by donor derived IL-2R beta(+) CD8(+) cells in bm1 mice, while both donor IL-2R beta(+) CD4(+) cells and host T cells were present in bm12 mice 2 weeks after BM transplantation. alpha IEL chain(+) cells and gamma delta T cells decreased in the intestine in bm1 mice, while host gamma delta T cells increased in the intestine of bm12 mice. In bm1 mice, infiltration of leukocytes was observed in the liver sinusoids and portal area. In bm12 mice, Leukocyte infiltration occurred around bile duct and submucosal area of the large intestine. Although most irradiated bm1 or bm12 mice that received lymph node cells alone died within 10 days, mice injected with BM cells and lymph node MNC surivived and expansion of IL-2R beta(+) T cells was less obvious. These results suggest that activated donor IL-2R beta(+) T cells are effecters for graft-versus-host disease across mutant MHC, and BM cells are needed for host survival and suppression of activated donor T cells.