Stat 6-dependent induction of myeloid derived suppressor cells after physical injury regulates nitric oxide response to endotoxin.

Objective: To delineate the role of T-helper 2 (Th2) cytokines in the induction of trauma induced myeloid suppressor cells (TIMSC) and the regulation of nitric oxide production.

Background: Trauma induces myeloid cells that express CD11b+/Gr1+ and arginase 1 and exhibit an immune suppressing activity. This article explores the mechanisms that induce TIMSC and the effects on nitric oxide production in response to endotoxin.

Nature of myeloid cells expressing arginase 1 in peripheral blood after trauma.

Background: Myeloid cells that express arginase 1 are upregulated by different stimuli, including trauma, and are capable of depleting arginine from the surrounding environment. Through arginine depletion, myeloid cells are capable of regulating T-cell function. We have previously reported increased arginase 1 expression in the peripheral blood mononuclear cells (PBMCs) after injury.