Induction of humoral and cellular responses in cynomolgus monkeys immunised with mannan-human MUC1 conjugates

Mice immunised with oxidised mannan conjugated to the human mucin 1 (MUCl), produce MHC Class 1 restricted CD8(+) cytotoxic T-cells which eradicate MU Cl+ tumours, indicating potential for the immunotherapy of MUCl+ cancers in humans. We now describe preclinical studies performed in cynomolgus monkey s immunised with human or murine MUCl conjugated to oxidised mannan, where immune responses and toxicity were examined. High titred antibodies specifi c for MUCl were produced, MUCl specific CD4(+) and CD8(+) T-cell proliferat ive responses and specific cytotoxic precursor cells (CTLp) were found, but not MUCl specific cytotoxic T-cells (CTL). There was no toxicity and monke ys can be immunised against human MUCl with mannan-MUCl conjugates, but a h umoral response (Th2 type) predominates. The results contrast with those ob tained in mice when a CTL response (Th1 type) predominates (C) 1999 Elsevie r Science Ltd. All rights reserved.