Characterization of antibodies against ceramidetrihexoside and globoside

1. When a carrier-hapten complex was used to raise antibodies in rabbits against ceramidetrihexoside, an antiserum was obtained in which the activity against the carrier could not be removed by absorption with the carrier without loss of the anti-hapten activity.

2. Antibodies against ceramidetrihexoside were raised in rabbits by immunizing them with a mixture of bovine serum albumin and the glycolipid according to Hakomori (1972). It was found that these antibodies cross-reacted with digalactosylceramide. but not with lactosylceramide or digalactosyldiglyceride. No cross-reactivity was observed with globoside in an artificial membrane system but a slight cross-reactivity was found with globoside absorbed on cholesterol microcrystals. A possible explanation for the latter phenomenon is discussed. From inhibition studies with different sugar compounds combined with the cross-reactivity studies, it can be concluded that anti-ceramidetrihexoside antibodies have a high and strict specificity for a terminal galactosyl α(1→ 4)galactosyl group.

3. Antibodies raised in rabbits against globoside by the method of Hakomori (1972) did not cross-react with the other glycolipids tested. The characteristics of these antibodies are compared with those of the anti-ceramidetrihexoside antibodies.

4. A human anti-P₁,P,P^k serum from a person with the rare phenotype p, which contains anticeramidetrihexoside (anti-P^k) activity was compared with the rabbit anti-ceramidetrihexoside serum. The two antisera showed very similar characteristics with regard to the anti-ceramidetrihexoside activity.