A recurrent clonotype in the spontaneous anti-IgG2a rheumatoid factor response of lpr/lpr mice.
We generated mice transgenic for a VH gene that partially encodes an anti-IgG2a rheumatoid factor. Such transgenic VH genes recombine at a low frequency with the endogenous Igh locus in mice, giving rise to a small number of B cells that express heavy chains partially encoded by the transgene. The transgenes were crossed onto an lpr/lpr background, and hybridomas were generated from the resulting mice at 3 to 6 mo of age. Analysis of the anti-IgG2a- producing hybridomas obtained revealed that none expressed the transgenic VH. Surprisingly, however, most of the mice yielded multiple anti-IgG2a hybridomas that expressed VH genes comprised of a single VH gene segment, D regions with highly homologous 5' ends encoding CDR3 regions of identical length, and the JH4 segment. Expressed light chain diversity among these hybridomas was also highly restricted; most expressed a single V kappa gene segment. All of the hybridomas expressed members of the V kappa 19/28 family. Many of the VH genes contained a low frequency of somatic mutation. The recurrence of this family of V regions is not due to an indirect transgene effect or to effects of the genetic background used to construct the mice, as hybridomas expressing the predominant V gene segment combination were also isolated from a transgene-negative lpr/lpr littermate and from MRL lpr/lpr mice. These data contrast with the previous findings of others that while the spontaneous rheumatoid factor response of lpr/lpr mice was oligoclonal, recurrent clonotypes were not apparent, and the VH and V kappas encoding these rheumatoid factors contained a high frequency of somatic mutation whose distribution and type were indicative of Ag-driven selection.
Hande
S
S
Department of Microbiology and Immunology, Thomas Jefferson Medical College, Philadelphia, PA 19017, USA.
Jacobson
B A
BA
Manser
T
T
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000235:genetics*; D001483:Base Sequence; D002999:Clone Cells; D005260:Female; D005803:Genes, Immunoglobulin / Q000276:immunology*; D007074:Immunoglobulin G / Q000235:genetics* / Q000276:immunology*; D007143:Immunoglobulin Heavy Chains / Q000096:biosynthesis / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000096:biosynthesis / Q000235:genetics; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D012217:Rheumatoid Factor / Q000096:biosynthesis* / Q000235:genetics*; D013154:Spleen / Q000166:cytology
D000888:Antibodies, Anti-Idiotypic; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; C048844:anti-IgG; D012217:Rheumatoid Factor