Lymphocyte-mediated macrophage apoptosis during IL-12 stimulation.

In contrast to the well known immunostimulatory roles of IL-12, little has been known about its immunosuppressive roles. In the present study, IL-12-activated lymphocyte-mediated macrophage apoptosis was investigated by employing murine lymphocyte/macrophage cocultures. IL-12-activated lymphocytes and their culture supernatants induced an inducible nitric oxide synthase (iNOS)-mediated nitric oxide (NO) synthesis in macrophages.

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

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.

Rosiglitazone prevents graft-versus-host disease (GVHD).

The effect of rosiglitazone, an agonist of peroxisome proliferator-activated receptor-γ (PPARγ), was investigated in a mouse parent-to-F1 GVHD model. Rosiglitazone inhibited mixed lymphocyte reactions, inducing enhanced apoptosis in CD4+, CD8+, and B220+ cells, but not in NK1.1+, Mac-1+, CD4+/CD25+ and CD3+/NK1.

Use of curcumin to decrease nitric oxide production during the induction of antitumor responses by IL-2.

Nitric oxide (NO) synthesis is strongly induced during interleukin (IL)-2 treatment of mice and humans. Although this free radical can act as a cytotoxic effector molecule against cancer cells, immunosuppressive effects have also been suggested. We evaluated the effects of curcumin on IL-2-induced NO synthesis and IL-2-induced antitumor responses in a mouse ascites tumor model.