EPSTEIN-BARR VIRUS-INDUCED MOLECULE-1 LIGAND CHEMOKINE IS EXPRESSED BY DENDRITIC CELLS IN LYMPHOID-TISSUES AND STRONGLY ATTRACTS NAIVE T-CELLS AND ACTIVATED B-CELLS

Movement of T and B lymphocytes through secondary lymphoid tissues is likely to involve multiple cues that help the cells navigate to approp riate compartments. Epstein-Barr virus-induced molecule 1 (EBI-1) liga nd chemokine (ELC/MIP3 beta) is expressed constitutively within lympho id tissues and may act as such a guidance cue. Here, we have isolated mouse ELC and characterized its expression pattern and chemotactic pro perties. ELC is expressed constitutively in dendritic cells within the T cell zone of secondary lymphoid tissues. Recombinant ELC was strong ly chemotactic for naive (L-selectin(bi)) CD4 T cells and for CD8 T ce lls and weakly attractive for resting B cells and memory (L-selectin(l o)) CD4 T cells. After activation through the B cell receptor, the che motactic response of B cells was enhanced. Like its human counterpart, murine ELC stimulated cells transfected with EBI-1/CC chemokine recep tor 7 (CCR7), Our findings suggest a central role for ELC in promoting encounters between recirculating T cells and dendritic cells and in t he migration of activated B cells into the T zone of secondary lymphoi d tissues.