Three chemokines with potential functions in T lymphocyte-independent and -dependent B lymphocyte stimulation

Three clustered mouse chemokine genes, ABCD-I, -2 and -3, are all expressed highly in dendritic cells and, at various levels, in activated B cells. T cell-independently activated B cells express ABCD-1 and -2, but not -3. T c ell-dependently activated B cells express all three, ABCD-I attracts activa ted CD8(+) cytotoxic T cells and CD4(+) helper T cells of type 1 and 2. ABC D-2 preferentially attracts type 2 helper T cells, while ABCD-3 does not at tract T cells at all. Both ABCD-1 and ABCD-2 bind to the same receptor (CCR 4). In addition, ABCD-1 binds to a second, unknown, receptor on a separate T cell population. The three chemokines might guide T cell-independent as w ell as -dependent responses with two types of CD4(+) T cells.