Immunochemical studies of organ and tumor lipids. XV. The reactivity of anti-lactose sera with cytolipin H

A total of ninety antisera were prepared in rabbits against foreign globulinazophenyl lactose conjugates and studied for their content of precipitating antibody with phloroglucinol triazophenyl lactoside and for complement-fixation reactions with cytolipin H (ceramide lactoside). Of sixty antisera with a content of anti-lactose protein in excess of 100 μg/ml, sixteen contained complement-fixing antibody with avidity for cytolipin H comparable to that observed with antisera to human tumor tissue. These anti-lactose sera were therefore useful serological reagents for the measurement of cytolipin H. The correlation between antibody content determined by precipitation with a synthetic lactoside and by complement-fixation with cytolipin H was poor. Some anti-lactose sera contained potent inhibitors of complement-fixation. Differences in character between anti-lactose antibody and anti-tissue antibody were evident from 1. differences in the sensitivity to inhibition by lactose of the complement-fixation reaction with cytolipin H and 2. differences in the precipitability of the two types of antibody by the lactoside test antigen. Anti-lactose sera are more specific than anti-tissue sera in reactions with lipid haptens.