Asthma Research Today is a free monthly online journal that collates and summarizes the latest research about Asthma, including details on symptoms, diagnosis, treatment, causes, medications. | ||||||||
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The leukotriene B4 lipid chemoattractant receptor BLT1 defines antigen-primed T cells in humans.Islam SA, Thomas SY, Hess C, Medoff BD, Means TK, Brander C, Lilly CM, Tager AM, Luster AD Center for Immunology and Inflammatory Diseases, Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, Charlestown, MA 02129, USA. We have recently shown that the leukotriene B(4) (LTB(4))-BLT1 pathway is important in early effector T-cell recruitment in mouse models of inflammation. Here we characterize the phenotype and function of human peripheral blood BLT1(+) T cells in health and illustrate their involvement in asthma and acute infection. In healthy individuals, BLT1(+) T cells are a rare peripheral blood T-cell population enriched for the activation markers CD38 and HLA-DR. Compared with BLT1(-) T cells, a larger proportion of peripheral blood BLT1(+) T cells express the effector cytokines IFNgamma and IL-4 and inflammatory chemokine receptors, CCR1, CCR2, CCR6, and CXCR1. Consequently, in healthy individuals peripheral blood BLT1(+) T cells are a rare antigen-primed T-cell subset with unique phenotypic, migratory, and functional properties. BLT1 expression on T cells is tightly regulated by inflammation and only transiently expressed after naive T-cell activation by dendritic cells. Although rare in the peripheral blood of healthy individuals, BLT1(+) T cells are markedly increased in frequency in the peripheral blood in response to acute Epstein-Barr virus (EBV) infection and moderately increased in the airways of asymptomatic allergic asthmatics. Our studies provide novel insights into the LTB(4)-BLT1 lipid chemoattractant pathway in human T-cell responses, and how it may link innate and adaptive immunity. Published 10 January 2006 in Blood, 107(2): 444-53.
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