Research reports from Y.Y. Chen and co-authors provide new insights into immunology
2007 NOV 21 -- "NK cells play critical roles in immune responses against tumors or virus infections by generating type 1 cytokine and cytotoxicity responses. In contrast, during type 2 dominant immune responses, such as allergic diseases, activities of NK cells are often impaired," researchers in the United States report. "These type 2 immune-mediated diseases have been reported to be closely associated with local production of PGD(2). PGD(2) is an eicosanoid primarily synthesized by mast cells and alveolar macrophages, and it functions through two major receptors, D prostanoid receptor (DP) and chemoattractant receptor-like molecule on the Th2 cell. Within the immune system, PGD(2) binding to DP generally leads to suppression of cellular functions. In the current study, we show that: 1) DP is expressed in human NK cells as detected by mRNA analysis and Western blot; 2) PGD(2) inhibits cytotoxicity, chemotaxis, and type 1 cytokine production of human NK cells via signaling through DP; 3) PGD(2) signaling via DP elevates intracellular cAMP levels and the inhibitory effects on NK cells are cAMP dependent; 4) PGD(2) binding to DP suppresses Ca2+ mobilization triggered by the cross-linking of the activating receptor, CD16," wrote Y.Y. Chen and colleagues. The researchers concluded: "Together, these data uncover a novel mechanism by which PGD(2) functions through DP to suppress type 1 and cytolytic functions of human NK cells, thus contributing to the promotion of a type 2 immune response." Chen and colleagues published their study in the Journal of Immunology (Prostaglandin D-2 suppresses human NK cell function via signaling through D prostanoid human receptor. Journal of Immunology, 2007;179(5):2766-2773). For additional information, contact K.S. Campbell, Fox Chase Cancer Center, Institute Cancer Research, Division Basic Science, 333 Cottman Avenue, Philadelphia, PA 19111, USA. Publisher contact information for the Journal of Immunology is: American Association Immunologists, 9650 Rockville Pike, Bethesda, MD 20814, USA. Keywords: United States, Philadelphia, Life Sciences, Interferon, Immunology. This article was prepared by Immunotherapy Weekly editors from staff and other reports. Copyright 2007, Immunotherapy Weekly via NewsRx.com.
|
