Role of C Chemokine Lymphotactin in Mediating Recruitment of Antigen-Specific CD62Llo 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 lymphotactin. We found that lymphotactin induced preferential migration of antigen-specific (CD62Llo) T cells over the nonspecific (CD62Lhi) T cells in vitro and in vivo. The differing migratory abilities correlated with higher levels of mRNA encoding the lymphotactin receptor (XCR1) on the CD62Llo cells compared to the CD62Lhi cells. Thus, we have identified a coupling mechanism between the activation of T cells and acquisition of new homing properties, in this case conferred by XCR1 expression. These data confirm that at least one function of lymphotactin includes mediating the recruitment of recently activated antigen-specific T cells.