Immune characteristics and homing capacity of CCR4-bearing T cells in vivo. (a) Immunophenotype of CCR4⁺CD4⁺ T cells. CD4⁺ T cells from 16- to 18-week-old diabetic NOD mice were incubated with the indicated Ab’s and then analyzed by flow cytometry to determine the CCR4 expression levels. Left column, CCR4^– (neg); center column, CCR4^low (low); right column, CCR4^high (high) populations. (b) Th1-type cytokine production by CCR4-positive cells. CCR4-positive (CCR4^low and CCR4^high) and -negative cells were cocultured with APCs for 3 days with Con A, GAD65, and media stimulation. Culture supernatants were examined by ELISA for their cytokine profiles. White bars, CCR4-negative cells/APCs; black bars, CCR4-positive cells/APCs. (c) Higher frequency and severity of insulitis of pancreatic islets of 8- to 10-week-old NOD-scid female recipients (each group, n = 2) 1 week after adoptive transfer of CCR4-positive and CCR4-negative CD4⁺ cells.