SELECTIVE EXPRESSION OF THE EOTAXIN RECEPTOR CCR3 BY HUMAN T-HELPER-2CELLS

There is growing evidence that T helper cell subsets (T(H)1 and T(H)2) can be differentially recruited to promote different types of inflamm atory reactions. Murine T(H)1 but not T(H)2 cells are recruited throug h P-and E-selectin into inflamed tissues, where they induce delayed-ty pe hypersensitivity reactions. The human eotaxin-receptor CCR3, origin ally described on eosinophils and basophils, was also found to be expr essed by T(H)2 cells. An antibody to CCR3 was used to isolate T cells from peripheral blood that give rise to T(H)2-polarized cell lines and to identify T(H)2 cells derived from naive T cells in vitro. Eotaxin stimulated increases in intracellular calcium and chemotaxis of CCR3() T cells. The attraction of T(H)2 cells by eotaxin could represent a key mechanism in allergic reactions, because it promotes the allergen- driven production of interleukin-4 and interleukin-5 necessary to acti vate basophils and eosinophils.