Role of C chemokine lymphotactin in mediating recruitment of antigen-specific CD62L(lo) cells in vitro and in vivo

In this study we investigated whether T cells expressing high or low levels of CD62L were differentially susceptible to the T cell. chemokine lymphota ctin. We found that lymphotactin induced preferential migration of antigen- specific (CD62L(lo)) T cells over the nonspecific (CD62L(hi)) T cells in vi tro and in vivo. The differing migratory abilities correlated with higher l evels of mRNA encoding the lymphotactin receptor (XCR1) on the CD62L(lo) ce lls compared to the CD62L(hi) cells. Thus, we have identified a coupling me chanism between the activation of T cells and acquisition of new homing pro perties, in this case conferred by XCR1 expression. These data confirm that at least one function of lymphotactin includes mediating the recruitment o f recently activated antigen-specific T cells. (C) 2001 Academic Press.