Production of antibodies of identical idiotype but diverse immunoglobulin classes by cells derived from a single stimulated B cell.

Abstract

The availability of anti-phosphocholine antibody of the TEPC 15 idiotype from the clonal progeny of a single precursor cell, stimulated in vitro, permitted the demonstration of monoclonal antibodies with as many as three immunoglobulin classes with identical variable regions. This demonstration was dependent on sensitive radioimmunoassays which showed a one to one relationship between the total anti-phosphocholine antibody produced by a clone and the sum of anti-phosphocholine antibody of the different classes as well as the amount of antibody of the TEPC 15 idiotype. The class distribution was confirmed by isoelectric focusing identification of IgM, IgA, and IgGI antibodies of the TEPC 15 idiotype produced by single clones which showed characteristic pl values for each immunoglobulin class. Thus, within the generative phase of a single antibody-producing cell clone, various heavy chain constant regions can be linked to the same variable region, and single precursor cells have the capacity to generate progeny expressing at least three distinct immunoglobulin classes.

Natural murine autoantibodies and conventional antibodies exhibit similar degrees of antigenic cross-reactivity.

“…[19]). The utility of the fragment culture system for this purpose was demonstrated by its ability to detect the antigenic cross-reactivity of hemagglutinin proteins expressed by influenza viruses (22) and the idiotypic cross-reactivity of antiphosphorylcholine responses (21). Our data support the intuitive expectation that antibody cross-reactivity increases as the affinity of the interactions examined decreases.…”

“…Such disparate results reflect differences in how these antibodies were generated and the affinity of the interactions involved. Antibodies produced in short-term splenic fragment cultures mirror the repertoire of B cells normally expressed by donor mice (16)(17)(18)(19)(20)(21)(22). Hybridomas arise from the fusion ofdonor B cells in a very specific stage of activation and differentiation.…”

“…The methodology for in vitro B cell cloning has been described previously (17)(18)(19)(20)(21)(22). Briefly, a single cell suspension made from the spleens of two to four donor mice was treated twice with anti-Thy 1.2 plus complement (resulting in < 2% T ventional antigens (TNP-KLH and ovalbumin) as described (16)(17)(18)24).…”

“…Previous work indicated that antibodies with an affinity of 5 X 106 M-I or greater could be detected in such a system (19). The antibodies present in these culture supernatants were monoclonal, as demonstrated by their expression of a single Ig heavy and light chain isotype (17)(18)(19)(20)(21)(22)(23).…”

Immunochemical evidence for a common variable region in three immunoglobulin classes in the same individual.

“…Fu et al (21) recently presented strong evidence for the occurrence of human lymphocytes simultaneously producing two immunoglobulins of different classes but with identical V-regions. Gearhart and associates (22) have also recently demonstrated that a single stimulated murine B cell may give rise to a progeny producing monoclonal immunoglobulins of G, M, and A classes which all share idiotypic determinants. The present findings are not incompatible with any of these hypotheses but it should be pointed out that if only the first hypothesis were valid the presence of cells simultaneously producing three classes of immunoglobulin has to be assumed.…”