T cell : B cell collaboration--the response to polysaccharide antigens.

The humoral response to polysaccharide antigens occurs as a result of T cell-B cell collaboration that is very different from the present understanding of the mechanisms whereby protein antigens are taken up, processed and exposed on the cell membrane in the context of MHC class II molecules in a manner suitable for recognition by a T cell antigen receptor. Two models, Wiskott-Aldrich syndrome and CBA/N mice bearing the xid mutation, are examined because in both cases there is a failure to respond to polysaccharide antigens.