Characterization of λ class antibodies from the BALB/c memory response to a [glucosyl-α(1 → 3) glucosyl]-protein conjugate

Both dextran B-1355 and nigerosyl-KLH (N-KLH) contain α(1 → 3) diglucosyl moieties and both induce λ class serum antibodies which recognize the α(1 → 3) linkage. However, as shown here, some of the antibodies induced by the thymus-dependent form, N-KLH, have a distinct fine specificity. It is known that B-1355 induces antibodies which resemble the anti-α(1 → 3) myeloma proteins MOPC 104E and J558. The new fine specificity which does not resemble such antibodies is found in the serum of N-KLH primed mice challenged with N-KLH. The two fine specificity types are distinguished by their sensitivity to inhibition by nigerose in ELISA using B-1355 or N-BSA as bound antigen. Twelve hybridomas were produced from N-KLH primed mice boosted with either N-KLH or B-1355. Six of the 12 had the new fine specificity; only two out of the 12 expressed the IdX determinant commonly associated with the B-1355 response and neither of these possessed the new reactivity pattern. Comparative inhibition with the disaccharide nigerose and the tetrasaccharide nigerantetraose indicated that 11 out of the 12 hybridoma proteins have combining sites larger than a disaccharide. Southern and Northern blot analysis of eight hybridomas revealed that all expressed V_H genes from the J558 family, but that at least two distinct V_H genes from this family were used. The data support the hypothesis that immunization with an α(1 → 3) diglucosyl-protein conjugate alters the composition of the B cell pool capable of producing λ class antibodies from that ordinarily observed following immunization with B-1355.