A single-step enrichment of Th2 lymphocytes using CCR4 microbeads

Monitoring the effector T cells in humans should provide important insights into the regulation of human immune responses and their pathologic consequences. To monitor immune responses it is desirable to be able to isolate greater numbers of effector T cells (Th1/Th2) from peripheral blood. Here, we describe a one step method to enrich for Th2 cell populations from human peripheral blood based on CCR4 expression on Th2 cells and compared it to the CRTh2-based isolation method. Th2 cells were isolated from PBMCs using anti-CCR4 or anti-CRTh2 antibodies and magnetic cell sorting. The mean purity of CD4+ T cells isolated using CCR4 approach from four independent donors was >80% whereas lymphocytes isolated using the CRTh2 approach gave poor yields (approximately 7%). Further, the CCR4 approach gave 8- to 10-fold greater numbers of Th2 cells, as compared to the CRTh2 method, isolated directly from peripheral blood. Upon activation with PMA and ionomycin, the purified CD4+CCR4+ T lymphocytes produced IL-4 and no IFN-gamma. This is a rapid and efficient method to enrich for Th2 effector cells from human peripheral blood.