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 CysLTreceptor and responsiveness to leukotrienes, peripheral blood mononuclear cells from house dust mite-allergic or nonallergic individuals were incubated with D. pteronyssinus allergen (Der p). Baseline CysLTexpression was similar in both groups of donors, but Der p significantly enhanced CysLTexpression in CD4+ and CD8+ T cells of only allergic individuals and induced enhanced responsiveness of CD4+ T cells to LTDin terms of calcium mobilisation. This effect was prevented by the CysLTantagonist MK571. Der p also induced IL-4 and IL-10 production, and neutralizing antibody to IL-4 prevented both the enhanced CysLTexpression and the enhanced responsiveness of T cells to LTDinduced 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 CysLTreceptors through a mechanism involving IL-4 production. This, in turn, would induce CD4+ T cell responsiveness to cysteinyl-leukotrienes and Th2 cell activation.