IG GENETICS--ONTOGENY AND DIFFERENTIATION OF CELLS OF THE RABBIT IMMUNE SYSTEM

我们使用经典的免疫遗传技术，以及技术

We use classical immunogenetic techniques as well as techniques of molecular biology to study the genetics of rabbit immunoglobulins (Igs) and T cell receptors and the regulated expression of the genes that encode these molecules. A rabbit cDNA copy of splenic mRNA is spliced to C mu from a site 635 bp 3' of the conserved octanucleotide of the heavy chain enhancer. A splice site is present at a similar position in the intron sequences of mouse and man. There is evidence that such spliced steril transcripts occur in developing B cells of mice and in some human cell lines. The evolutionary conservation of the spliced mRNA in these three species suggest that it may play a functional role during B cell ontogeny. We are characterizing T cell receptor C beta genes from rabbits which have three copies of the C beta constant region. We previously demonstrated that there are allotypes of rabbit C beta1. We have now sequenced about 4 kb of cloned 6 kb fragment from an animal of type b and demonstrated that this fragment contains a rabbit C beta2 gene. Comparisons with the cDNA sequence from an animal of C beta type a show replacement changes in the first and third exons thus demonstrating that there are also allotypic forms of C beta2. Decreased galactosylation of IgG that is observed in a sera of rheumatoid patients is also observed in the IgG prepared from sera of rabbits post-immunization with Streptococcal vaccines. Therefore the difference in IgG galactosylation seen in patients may also be induced rather than reflect an inherent genetic difference in individuals with rheumatoid disease.