Glutamine protects mice from acute graft-versus-host disease (aGVHD)

•The effect of glutamine administration on GVHD was evaluated in a mouse model.•Glutamine therapy improved the microscopic findings of GVHD of target organs.•Glutamine therapy improved the survival of GVHD mice.•Glutamine therapy decreased the serum levels of TNF-α in GVHD mice.•Glutamine therapy increased the fractions of blood CD4+/CD25+ cells in GVHD mice. Despite current immunosuppressive therapies, acute graft-versus-host disease (aGVHD) is a major cause of morbidity and mortality in allogeneic hematopoietic stem cell transplantation (HSCT). In the present study, therapeutic effects of intraperitoneal glutamine (Gln) administration (1g/kg/day) in a mouse aGVHD model were evaluated. Gln administration significantly inhibited the GVHD-induced inflammation and tissue injury in the intestine, liver, skin and spleen. Gln therapy improved the score of clinical evidence of aGVHD and prolonged the median survival of aGVHD mice. Gln administration in aGVHD mice increased the fraction of Foxp3+/CD4+/CD25+ cells in the blood measured on day 7, and decreased the serum levels of tumor necrosis factor-α measured on days 7, 14 and 21 after aGVHD induction. These results demonstrated that Gln administration may be useful in protecting the host from aGVHD.