MHC class II participates in IFN-γ induction by HTLV-1 Env and Tax peptides.

Flow cytometric data showed that IFN-γ production was inhibited by the addition of an anti–class II mAb, whereas the addition of an anticlass I mAb had no effect. PBMCs were isolated from one infected individual, cultivated in vitro with or without peptides and with or without the respective blocking antibodies.