Enhanced Cysteinyl-Leukotriene Type 1 Receptor Expression in T Cells from House Dust Mite-Allergic Individuals following Stimulation with Der p

Abstract

In order to determine the potential for allergen to modulate T cell expression of the CysLT1receptor and responsiveness to leukotrienes, peripheral blood mononuclear cells from house dust mite-allergic or nonallergic individuals were incubated withD. pteronyssinusallergen (Der p). Baseline CysLT1expression was similar in both groups of donors, but Der p significantly enhanced CysLT1expression in CD4+and CD8+T cells of only allergic individuals and induced enhanced responsiveness of CD4+T cells to LTD4in terms of calcium mobilisation. This effect was prevented by the CysLT1antagonist MK571. Der p also induced IL-4 and IL-10 production, and neutralizing antibody to IL-4 prevented both the enhanced CysLT1expression and the enhanced responsiveness of T cells to LTD4induced by Der p. In allergic individuals, Der p also induced T cell proliferation and a Th2-biased phenotype. Our data suggest that, in allergen-sensitized individuals, exposure to allergen can enhance T cell expression of CysLT1receptors through a mechanism involving IL-4 production. This, in turn, would induce CD4+T cell responsiveness to cysteinyl-leukotrienes and Th2 cell activation.