Carbohydrate peptide mimics: effect on MUC1 cancer immunotherapy

Recent clinical studies with mannan mucin immunotherapeutic agents indicate that patients produce predominantly antibody responses while mice produce a high cytotoxic T lymphocyte response. In studying the reason for the 'imm une deviation' occurring in mice to humans from cellular to antibody respon ses, it has been found that natural anti-Gal alpha(1,3)Gal antibodies, pres ent in all humans, react with the mucin component of the agent, providing a n example of a carbohydrate-peptide mimic. The immune deviation can be over come by in vitro sensitization of antigen-presenting cells in the absence o f anti-Gal antibodies - at least in mice. The review examines the backgroun d of these observations and discusses other peptide carbohydrate mimics and immune deviation.