CCR4 and CCR5 as amarker of Th2 and Th1 Cells in human peripheral blood lymphocytes

Abstract

Chemokine receptors play important roles in controlling the migration of lymphocytes to lymphoid and non-lymphoid tissues. Recent studies have shown that CCR4 is preferentially expressed on type 2 helper T (Th2) cell lines producing interleukin-4 (IL-4) and IL-13, and CCR5 is expressed on type 1 helper T (Th1) cell lines producing interferon-γ (IFN-γ). In this study, we investigated how CCR4 and CCR5 are expressed on peripheral blood T lymphocytes from 33 healthy individuals. CCR4 and CCR5 marked two distinct subsets of memory T lymphocytes expressing CD45RO in a mutually exclusive manner. Among CD4⁺ memory T lymphocytes, 10-20% expressed CCR4 but not CCR5 and 15-25% expressed CCR5 but not CCR4. In contrast, the majority (50-70%) of CD8⁺ memory T lymphocytes expressed CCR5 but not CCR4. After in vitro stimulation, CCR4+ cells isolated from memory T lymphocytes predominantly contained IL-4-producing cells (15%) over IFN-γ-producing cells (2%) and, conversely, CCR5⁺cells predominantly contained IFN-γ-producing cells (60%) but only a few IL-4-producing cells (3%). These results indicated that CCR4 and CCR5 can be useful surface markers of Th2 and Th1 cells in human peripheral blood T lymphocytes.