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

Recently, Nakano et al. described an autosomal recessive mutation in mice, paucity of lymph node T cells ( plt ), which leads to a defect in the homing of naive T lymphocytes to secondary lymphoid organs (28, 29) . plt mice have greatly decreased numbers of naive T lymphocytes in LNs, PPs, and the white pulp of spleen. When injected into plt mice, T lymphocytes from wild-type ( Ï© / Ï© ) mice fail to enter LNs and PPs and accumulate only in the red pulp of spleen, whereas lymphocytes from plt mice home normally in Ï© / Ï© mice. These findings demonstrate that the plt defect affects a gene expressed in the lymphoid organ stroma. Although the exact mutation has not been identified, the plt locus maps to mouse chromosome 4 in a region syntenic to human chromosome 9p13. Two known human chemokine genes map to 9p13: SLC and EBV-induced molecule 1 ligand chemokine (ELC) (19) .