Variable region gene selection of immunoglobulin G-expressing B cells with specificity for a defined epitope on type II collagen.

Immunization with type II collagen (CII) induces collagen-induced arthritis (CIA) in animals, and B cells reactive with CII are involved in the induction and manifestation of the disease. In this study, B cell hybridomas producing IgG antibodies specific for a major epitope on mouse CII (the "C1" epitope, amino acid 316-333), were isolated 11 days after immunization from draining lymph nodes in DBA/1 mice. Injection into neonatal mice of purified and biotinylated monoclonal antibodies binding the C1 epitope led to a specific binding to joint cartilage, demonstrating that the antibodies interact with native antigen in vivo. cDNA sequencing of the B cell clones revealed that they all expressed the same combination of a variable heavy chain (VH J558 family) and light chain (V kappa 21 family) germ-line gene, apparently lacking somatic mutations. The presence of isotype-switched B cells expressing a certain combination of V genes encoding antibodies that bind epitopes in vivo, indicates that this B cell population has been peripherally selected.