Abstract

MUC1 has been used as a target for immunotherapy and with oxidised mannan in mice there is selective delivery into the class I pathway and the induction of a T1 response. We have also been working in pig-to-human transplantation and of particular interest is the description in humans of natural Galalpha(1,3)Gal antibodies (Abs) which react with pig tissues. A peptide mimic (DAHWESWL) to the Galalpha(1,3)Gal sugar was found in a phage display library and is also mimicked by MUC1 peptides. It was of interest to note that while mice make cytotoxic T cells (CTLs) and little Ab to MUC1, humans make the reverse immune response. It was found that the cross reaction of the natural Galalpha(1,3)Gal Abs in humans to MUC1 was likely to be responsible for the diversion. Cross reactions are therefore an important problem in tumour immunotherapy, although the problem can be overcome by in vitro immunisations.