In vivo effects of IL-10 on transferred OVA-specific CD8⁺ OT-1 T cells.

Isolated OT-1 T cells, as in Figure 7, were adoptively transferred into syngeneic C57BL/6 mice followed by no treatment or by the administration of IL-10 for 7 days. (A) IL-10 did not modulate the frequency of adoptively transferred naive OT-1 T cells, but IL-10 increased the number of activated OT-1 T cells. (B) Cytotoxicity mediated by transferred, activated OT-1 T cells was also augmented by IL-10. In contrast, specific CTL activity was not observed in animals receiving naive OT-1 T cells with or without IL-10. Mice receiving activated OT-1 T cells and IL-10 displayed statistically increased frequencies of specific spleen effector cells against EG.7-OVA in the ELISPOT assay. (In activated transfer groups, with IL-10 vs without IL-10 [P < .005].) (C) They also displayed statistically increased frequencies of OVA peptide-specific spleen effector cells in the ELISPOT assay. (In activated T-cell transfer groups, with IL-10 vs without IL-10 [P < .001].)