Helper peptide G89 (HER-2:777-789) and G89-activated cells regulate the survival of effectors induced by the CTL epitope E75 (HER-2, 369-377). Correlation with the IFN-gamma: IL-10 balance.

The CTL response to Ag expands after priming and subsequently contracts reducing the number of effectors. CD4+ cells are described as regulators of CTL immunity. To elucidate whether CD4+ cells are involved in survival of effector CTL and the survival signals, we used CTL and Th peptides form the HER-2 protooncogene recognized in association with HL-A2 and HLA-DR4, respectively.