Isogeneic monoclonal antibodies against anti‐α(1 → 3)dextran idiotypes I. Isotypes, idiotope specificity and representation of idiotopes in antisera from mice of various genetic constitutions

Publisher Website
Google Scholar
Abstract
Eight isogeneic anti‐idiotypic hybridomas were raised against BALB/c myeloma protein MOPC104E and one against J558. Both myelomas react specifically with the α(1 → 3) glucosidic linkage of dextran B1355 fraction S (Dex). Six anti‐MOPC 104E proteins were IgG1, one was IgG2b and one IgM. The anti‐J558 protein was IgG1. Competitive interactions of the anti‐idiotopes and antigen with anti‐Dex proteins were measured. Dex itself was effective, but also an α(1→3) glucosidic heptasaccharide (N7‐CHO). In order to assess the anti‐idiotope specificity of hybridoma proteins, three anti‐Dex molecules were used: MOPC 104E, J558 and hybridoma protein Hdex14. These differed from each other in VH amino acid positions 54–55, or 100–101, respectively. By their serological reaction pattern our anti‐idiotope proteins could be divided into 3 groups: cross‐reactive, partially cross‐reactive and strictly specific for the immunogen. The latter ones were in the majority, and were called “private”, in contrast to the cross‐reactive “public” anti‐idiotopes. The serological pattern was followed, in general, by the mouse‐to‐mouse distribution of idiotopes in physiological anti‐Dex sera. Public idiotopes were closely correlated in their expression with anti‐Dex activity. “Private” idiotopes showed no correlation, and displayed a characteristically high degree of fluctuation from mouse to mouse. Among the different mouse strains that were compared with respect to idiotope expression in anti‐Dex sera, two stand out: C57BL‐Igha, which carries chromosome 12 of BALB/c, (as selected through allotype) on the C57BL/6 genome, and BALB‐Ighb, dex+, a recombinant in chromosome 12 linking the dex+ trait from BALB/c to the CH allotype from C57BL/6. The latter strain expressed significantly more of the private idiotopes than the former. This observation is discussed in terms of the position effect of classical genetics and network concepts.