Mice Lacking Expression of Secondary Lymphoid Organ Chemokine Have Defects in Lymphocyte Homing and Dendritic Cell Localization

Gunn, Michael D.; Kyuwa, Shigeru; Tam, Carmen; Kakiuchi, Terutaka; Matsuzawa, Akio; Williams, Lewis T.; Nakano, Hideki

Although the molecular mechanisms have not been elucidated, naive lymphocytes are believed to enter the white pulp of spleen by a series of adhesive and chemotactic steps similar to those that occur in LNs. The lack of T cells in the white pulp of spleen in plt mice suggests that SLC is also required for the entry of naive T cells into the T cell zones of spleen. By analogy with the defect seen in LNs, it is plausible that SLC provides the stimulus for an integrin activation step that is required for movement of naive T cells into the white pulp of spleen. SLC may also provide a chemotactic stimulus that guides naive T cells into the T cell zones of LNs and spleen. However, this function is unlikely to be unique, as other lymphocyte-specific chemokines such as ELC and DCCK1 are expressed in T cell zones (41, 44) . ELC has been shown to be more potent than SLC against naive T cells, and therefore may predominate in providing a chemotactic stimulus within the T cell zone (39) .