RESUMO
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.
Assuntos
Separação Celular/instrumentação , Separação Celular/métodos , Microesferas , Receptores de Quimiocinas/metabolismo , Células Th2/citologia , Células Th2/metabolismo , Humanos , Magnetismo , Receptores CCR4RESUMO
Prior time-course investigations of cerebral asymmetries in word processing have sometimes reported hemisphere differences in the onset and duration of semantic priming. In the current study, very strongly related word pairs (categorical associates such as arm-leg) were employed in a low relatedness proportion lexical decision priming paradigm. A range of prime-target stimulus onset asynchronies (SOAs: 150-800 ms) was included. Only very weak evidence was obtained for a LVF priming lag at the briefest SOA, while priming was bilateral at moderately long SOAs. We consider these data in the context of previous time-course studies and suggest that, when highly semantically similar word pairs are used, a right hemisphere priming lag is, at best, a very small effect.