The purpose of the present study was to evaluate the effects of graft-versus-host disease (GVHD) prophylaxis with the Janus kinase 3 (JAK3) inhibitor WHI-P131/ JANEX-1 on the graft-versus-leukemic (GVL) function of marrow allografts in mice undergoing bone marrow transplantation (BMT) after being challenged with an otherwise invariably fatal dose of BCL-1 leukemia cells. GVHD prophylaxis using WHI-P131 markedly improved the survival outcome after BMT. The probability of survival at 30 days after BMT was 11% ؎ 6% for vehicle-treated recipients
Here we show that the Janus kinase 3 (JAK3) inhibitor 4-(3'-hydroxyphenyl)-amino-6,7-dimethoxyquinazoline (JANEX-3) exhibits potent anti-GVHD activity and consequently improves the post-BMT survival outcome of C57BL/6 (H-2b) recipient mice transplanted with allogeneic bone marrow/splenocyte (BM/S) grafts from MHC disparate BALB/c mice (H-2d). One hundred percent of the vehicle-treated allograft recipients developed severe GVHD and died with a median survival of 41 days. Treatment of recipient mice with JANEX-3 (30 mg/kg/day, 3 x/day) after the onset of rapidly progressive severe GVHD in the 3rd week after BMT significantly improved the survival of BMT recipients with GVHD and prolonged the median survival time to 78 days (P < 0.0001, log-rank test). The probability of survival at two and three months post-BMT was 6 +/- 6% and 0 +/- 0% for vehicle-treated control mice and 100 +/- 0% and 38 +/- 17% for mice treated with JANEX-3. These results prompted the hypothesis that JAK3 plays a pivotal role in the pathophysiology of GVHD. To test this hypothesis, we examined if mice transplanted with allogeneic BM/S grafts from Jak3 knockout mice Jak3-/- develop GVHD. The allografts from (Jak3-/-) C57BL/6 (H-2b) mice rescued MHC-disparate recipient BALB/c mice (H-2d) of the lethal toxicity of TBI without causing fatal GVHD. Taken together, these observations establish JAK3 as a key mediator of severe GVHD after allogeneic BMT in the context of a major-HLA disparity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.