EXPRESSION OF L-SELECTIN (CD62L) DISCRIMINATES TH1-LIKE AND TH2-LIKE CYTOKINE-PRODUCING MEMORY CD4(-CELLS() T)

Human memory (CD45RO(+)) CD4(+) T cells can be distinguished into two subpopulations on the basis of expression of the lymph node homing rec eptor, L-selectin (CD62L). In a prior study we showed that human L-sel ectin-positive memory T-helper (Th) cells promote the maturation of Ig G- and IgA-producing cells by naive B cells. To further elucidate the contribution of memory CD4(+) T cells to B-cell differentiation, human memory CD4(+) T cells with or without L-selectin expression were eval uated for production of cytokines that participate in immunoglobulin p roduction. it was found that L-selectin-positive human memory CD4(+) T cells produce mainly interleukin (IL)-4 and IL-5, whereas L-selectin- negative CD4(+) T cells produce mainly interferon-gamma (IFN-gamma). T his profile of cytokine expression coincides with the profile that dis tinguishes Th1 and Th2 subsets. In contrast to the murine system, IL-1 0 production was similarly contributed by human L-selectin-positive an d -negative memory CD4(+) T-cell subpopulations. These results suggest that the human L-selectin-negative and -positive subpopulations of hu man memory CD4(+) T cells contain Th1-like and Th2-like cytokine-produ cing cells, respectively.