Delayed Sensitization to Purified Blood Group Substances in the Guinea Pig

Abstract

Guinea pigs sensitized by intradermal or footpad injection of purified blood group substances, in complete adjuvant or in saline, developed typical delayed hypersensitivity to both homologous and heterlogous antigens, as well as humoral antibody more or less specific for the homologous antigen in each case. Some degree of cross-reactivity was observed between the blood group substances and A(H) prepared from hog mucin and pneumococcal S XIV polysaccharide. The delayed reactions observed, on the basis of control studies, appeared to involve the blood group substances themselves rather than contaminant small molecules. Reasons are presented for concluding that specificity was determined by the backbone structure of these molecules rather than their surface configuration.