Donor CD8+ T cells deficient in DNAM-1 showed significantly less proliferation and infiltration of the liver and intestines of recipient mice and produced less IFN- after coculture with allogeneic splenocytes than WT CD8+ T cells

Donor CD8+ T cells deficient in DNAM-1 showed significantly less proliferation and infiltration of the liver and intestines of recipient mice and produced less IFN- after coculture with allogeneic splenocytes than WT CD8+ T cells. the antibody after the overt onset of GVHD ameliorated GVHD and prolonged survival. Finally, we show that this antiCDNAM-1 antibody therapy also ameliorated the overt GVHD in lethally irradiated mice after MHC-matched, minor antigen-mismatched bone marrow transplantation. These results indicate that DNAM-1 plays an important role in the development of GVHD and is an ideal molecular target for therapeutic approaches to GVHD. and = 14) or KO B6 (= Naproxen 16) mice. B6C3F1 mice that received irradiation only are also shown (= 5). Data are representative of two impartial experiments. (= 10 in each group). Data are pooled from two impartial experiments. (= 9) or KO (= 18) CBF1 mice received splenocytes from DNAM-1 WT B6 mice. DNAM-1 WT and KO CBF1 mice that received irradiation alone are also shown (= 5 and 7, respectively). The experiments were independently performed four times and pooled data from all of the experiments are shown. To next examine which cell type of donor cells expressing DNAM-1 plays a critical role in the development of GVHD, we prepared both CD4+ and CD8+ T cell-depleted splenocytes (TCD-SP) from WT B6 mice, and TCD-SP reconstituted with CD4+ (derived from DNAM-1 WT or KO mice) and CD8+ T cells (derived from DNAM-1 WT or KO mice). In contrast to B6C3F1 mice that received TCD-SP alone, recipient mice transplanted with TCD-SP reconstituted with any combinations of CD4+ and CD8+ T cells showed significantly higher levels of ALT and IFN- (Fig. S1 and and and = 14) or control antibodies (= 16) every other day from day ?1 until day 17 after transplantation. B6C3F1 mice that received irradiation only are also shown (= 10). Data were pooled from three impartial experiments. (= 3) on day 14 after transplantation were separated, and each donor-derived (H-2Kk?) lymphocyte subset was determined by flow cytometry. Data are representative of two impartial experiments. ( 0.05. Error bars show SD. DNAM-1 Costimulation Promotes Proliferation of and IFN- Production by Alloreactive CD8+ T Cells. DNAM-1 mediates a costimulatory signal in cytotoxic T cells and promotes cytotoxicity against target cells expressing DNAM-1 ligands (30, 31). To examine whether DNAM-1 is also involved in the costimulatory effect on proliferation of donor CD8+ T cells after priming in vivo, we transplanted 5-(and 6)-carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled splenocytes T Naproxen cells from B6 mice into sublethally irradiated B6C3F1 or B6 mice. In contrast to CD8+ T cells transplanted into syngeneic mice, most DNAM-1 WT CD8+ T cells transplanted into allogeneic mice had divided at 3 d after transplantation (Fig. S6and and and 0.005; * 0.05. Error bars show SD. DNAM-1 Ligand Expression in Target Organs in Acute GVHD. Naproxen We next examined the DLL1 expression of DNAM-1 ligands and in target organs in acute GVHD. was expressed predominantly in the liver, large and small intestines, and kidney (Fig. S7). Although was expressed at the highest levels in the heart and kidney, the liver and large and small intestines also expressed a significant amount of (Fig. S7). These results suggest that up-regulation of DNAM-1 on alloreactive CD8+ T cells and constitutively high expression of the ligands, particularly CD112, in the liver and intestines are important in the pathogenesis of GVHD. Indeed, the levels of functional DNAM-1 expression detected by TX42 mAb on donor CD8+ T cells were significantly correlated with ALT values (Fig. 4and Fig. S8 and and = 11) or control antibodies (= 11) every week from day 14 until day 77 after transplantation (= 19) or control antibodies (= 19) once on day 14 (= 8 or 9). (= 8) or control antibodies (= 8) once on day 14. Recipient B6 mice that received transplantation with bone marrow cells.