T-cell receptor alpha-chain variable-region haplotypes of normal and autoimmune laboratory mouse strains.

Abstract

We used Southern blotting and mRNA analysis to characterize allelic polymorphisms among genes of the T-cell antigen receptor (TCR) a-chain variable-region (V.) locus in a large panel of normal and autoimmune-susceptible or autoimmune-contributing strains of laboratory mice. Four major V. haplotypes were defied on the basis of multiple restriction fragment length polymorphisms for each of nine V.subfamily probes used. Southern blotting also revealed haplotype-specific loss of bands within some Va subfamilles, consistent with the deletion of particular V. genes The antigen-specific receptor on the majority of mature helper and cytotoxic T cells is a disulfide-linked heterodimer composed of polymorphic a and f3 chains that, like immunoglobulins, are encoded by variable (V), diversity (D; p chains only), joining (J), and constant (C) region gene segments (1). As with immunoglobulin genes, T-cell antigen receptor (TCR) a-and p8-chain genes develop a highly diverse, germ-line-encoded repertoire by means of somatic recombination of their polymorphic V-J or V-J-J elements (2-5).. In the mouse, the p-chain locus consists of an estimated 25-30 V genes, arranged in a minimum of 17 one-to three-member subfamilies (6, 7), and two C-region genes, each with a single upstream D element and six J elements (8-11). The murine a-chain locus consists of perhaps 100 V genes, arranged in an estimated 15-20 subfamilies of 1-10 homologous members each (12), and a single C-region gene with more than 50 upstream J elements (13,14). Both Va and V13 gene sequences show a high degree of diversity, displaying 40-70%o nucleotide sequence homology among members of different Va or V1 gene subfamilies (6,7,12,15).In addition to germ-line, junctional, and combinatorial mechanisms for the generation of diversity, allelic polymorphism plays a potentially important role in defining the overall TCR repertoire available to the mouse species.Although such polymorphism appears to be limited among Vat genes (16), information obtained so far for the Va locus suggests a considerable degree of polymorphism, including restriction fragment length polymorphisms (RFLPs) at the Va subfamily level (12) as well as numerous nucleotide substitutions characterizing allelic VY genes (17). Such germ-lineencoded differences in the TCR repertoire may play a role in tolerance, in immune responsiveness, and in genetically determined susceptibility to various types of spontaneous and induced autoimmune diseases (18)(19)(20)(21)(22)(23). We have therefore undertaken a more complete characterization of murine TCR Va (and V,3) haplotypes and the strains carrying them, with particular regard to strains that serve as murine models of systemic and organ-specific autoimmunity.MATERIALS AND METHODS Genomnic Blot Analysis. Genomic DNA was digested to completion with the desired restriction endonuclease, separated in 0.8% agarose gels, and blotted onto nitrocellulose filters according to standard protocols (24). V133, V13S, and V1'J6 probes were obtained from I). Pardoll ...

Analysis of the T cell receptor (TcR) regions in the NOD, NON and CTS mouse strains define new TcR Vα haplotypes and new deletions in the TcR Vβ region

“…The hybridization profile of the NOD mouse obtained with most of the V, probes for all three enzymes were similar to that seen in the SJL mice in agreement with the results of Singer et al [20]. Hybridization with V, 7 and V, 8 probes showed minor differences between the fragment pattern detected in the NOD and SJL mice (Fig.…”

Polymorphism ofTcrb andTcrg genes in Biozzi mice: Segregation analysis of a newTcrg haplotype with antibody responsiveness

“…Little is known about the specificity and restriction of 3,6 T cells, but they do seem, at least in mice, to be involved in the protection against bacterial infections in skin and mucosal tissues (Modlin et al 1989). Different Tcra, b, and g haplotypes have already been reported in inbred laboratory mice and wild mice Behlke et al 1986;Singer et al 1988;Rathbun et al 1988;Nobuhara et al 1989). …”

A Tcra congenic mouse: V? epitope expression is influenced by both Tcra haplotypes and background genes

“…Knowledge is also scarce about a possible shaping influence of the polymorphic Tcra-V gene segments on the Tcr repertoire [however, see Epstein and co-workers (1986)]. A hindrance to such studies have been the Tcra-V germline differences between mouse strains manifested as Tcra haplotypes (Singer et al 1988;Klotz et al 1989;Jouvin-Marche et al 1989). To overcome this problem, we have established a congenic mouse in which the entire Tcra haplotype has been transferred from one strain to another.…”