Association of membranous nephropathy with T-cell receptor constant beta chain and immunoglobulin heavy chain switch region polymorphisms

Sex-Related Differences in Allelic Frequency of the Human Beta T Cell Receptor SNP rs1800907: A Retrospective Analysis from Milan Metropolitan Area

This paper aims at retrospectively re-analyzing the different distribution, between males and females, in the allelic frequency of the human β T cell receptor (TCR β) single nucleotide polymorphism (SNPs) rs1800907 in Caucasian patients in the Milan metropolitan area. The allelic frequency significantly differed between sexes. Females showed higher frequency of C/C genotype than males, but lower T/C genotype (p < 0.0001). Heterozygous (T/C) versus homozygous (T/T + C/C) genotypes resulted in a different distribution of frequencies in males than in females, the latter possessing higher homozygosis (p < 0.0001). Within the limitations of this work (small number of included studies that concerned just a specific geographical area), allelic distribution according to sex might account the role of TCRβ-related SNPs in autoimmune diseases and further investigations are required to explain better this genetic background, in the perspective of a sex-related T cell immune responsiveness and auto-immunity.

Ongoing immunoglobulin class switch DNA recombination in lupus B cells: analysis of switch regulatory regions

Inflammation and tissue damage in systemic lupus erythematosus (SLE) are mediated by class-switched autoantibodies reactive with nucleic acids, nucleic acid-binding proteins, phospholipids and other self-antigens. While some healthy individuals produce IgM antibodies with specificities similar to those of lupus patients, immunoglobulin class switching to mature downstream isotypes appears to be required for the generation of pathogenic autoantibodies. To characterize the cellular and molecular basis of pathogenic autoantibody production in SLE, we studied the capacity of peripheral blood B cells of naive phenotype from patients with SLE, rheumatoid arthritis (RA) or healthy control subjects to spontaneously switch to IgG and IgA. In addition, we determined the DNA sequences of the upstream evolutionary conserved sequence (ECS)-Igamma promoter regulatory regions that control germline IH-CH transcription and class switch DNA recombination (CSR) to IgG1, IgG2 and IgG4. IgM+IgD+ B cells from patients with SLE, but not those from RA or healthy control subjects, underwent spontaneous CSR, as assessed by expression of germline Igamma1-Cgamma1, Igamma2-Cgamma2, Igamma3-Cgamma3, Igamma4-Cgamma4 and Ialpha1-Calpha1 transcripts, mature (switched) VHDJH-Cgamma1, VHDJH-Cgamma2, VHDJH-Cgamma3 and VHDJH-Calpha1 transcripts and secreted IgG and IgA. Although polymorphic DNA sequences were identified in the ECS-Igamma1, ECS-Igamma2 and ECS-Igamma4 promoter regions, the transcription factor-binding sites that mediate germline Igamma-Cgamma transcription were conserved in patients and controls. However, distinct patterns of nuclear protein binding to an ECS-Igamma promoter sequence that contains both positive and negative regulatory elements were observed in SLE patients and controls. These results support a role for exogenous signals, such as through CD40 ligation, rather than altered genomic sequence, in the increased production of class switched autoantibodies in SLE.

A common T/C polymorphism in the promoter region of the beta T-cell receptor gene

Polymorphisms in the T-cell receptor genes can provide important information for the study of the immune response system, particularly for autoimmune diseases. This report characterizes a common T to C polymorphism in the promoter of the beta 2 constant chain of the T-cell receptor, which abolishes a recognition site for BglII restriction endonuclease.

Evolution and selection of primate T cell antigen receptor BV8 gene subfamily

The set of potential T cell receptor specificities is highly diverse. The relative contributions of T cell receptor (TCR) V beta gene segment polymorphisms, duplications, deletions, and gene conversions to this final T cell receptor protein diversity are unknown. To study these mechanisms, we sequenced and compared closely related primate TCR gene segments from BV8S1, S2, and S5. Interspecies comparisons show that these gene segments have sustained multiple duplication, gene conversion, and deletion events during the last 35 million years of anthropoid primate evolution. BV8 coding sequences are generally conserved with respect to their flanking noncoding sequences, but we find no evidence for positive or negative selection in sequences coding for the first two putative complementarity-determining (ligand-binding) regions. Sequences of TCRBV8 gene segments from unrelated humans demonstrate no nonsynonymous substitutions in nonleader regions of either the BV8S1 or S2 gene segments. We conclude that gene duplication, deletion, and conversion mechanism contribute in a substantial way to the overall diversity of the TCRBV8 gene segment repertoire in primate evolution and that germline substitutions and consequent polymorphisms in CDRs 1 and 2 of these gene segments probably do not play an active role in generating TCR beta chain protein variation.

TCR gene polymorphisms and autoimmune disease

Autoimmunity may result from abnormal regulation within the immune system. As the T cell is the principal regulator of the immune system and its normal function depends on immune recognition or self/non-self discrimination, abnormalities of the idiotypic T-cell receptor (TCR) may be one cause of autoimmune disease. The TCR is a clonally distributed, cell-surface heterodimer which binds peptide antigen when complexed with HLA molecules. In order to recognize the variety of antigens it may possibly encounter, the TCR, by necessity, is a diverse structure. As with immunoglobulin, it is the variable domain of the TCR which interacts with antigen and exhibits the greatest amount of amino acid variability. The underlying genetic basis for this structural diversity is similar to that described for immunoglobulin, with TCR diversity relying on the somatic recombination, in a randomly imprecise manner, of smaller gene segments to form a functional gene. There are a large number of gene segments to choose from (particularly the TCRAV, TCRAJ and TCRBV gene segments) and some of these also exhibit allelic variation. Finally, polymorphisms in non-coding regions of TCR genes, leading to biased recombination or expression, are also beginning to be recognized. All these factors contribute to the polymorphic nature of the TCR, in terms of both structure and repertoire formation. It follows that inherited abnormalities in either coding or regulatory regions of TCR genes may predispose to aberrant T-cell function and autoimmune disease. This review will outline the genomic organization of the TCR genes, the genetic mechanisms responsible for the generation of diversity, and the results of investigations into the association between germline polymorphisms and autoimmune disease.

Restriction fragment length polymorphism of the T cell receptor beta-chain gene in Chinese patients with thyrotoxic hypokaleamic periodic paralysis and Graves' disease

Restriction fragment length polymorphism (RFLP) of the T cell receptor beta-chain gene was studied in two groups of Chinese thyrotoxic patients, those with thyrotoxic hypokaleamic periodic paralysis (THPP) and those with Graves' Disease (GD). DNA digested with restriction enzymes Bgl II, Bam HI, Eco RI, Pvu II and Taq I were hybridized to a 770 bp TcR beta cDNA probe containing the joining (J) and constant (C) region segments. The TcR beta/Bgl II polymorphism of 9.2 kb and 10 kb fragments were observed in THPP, GD and normal controls. The genotype frequencies of this polymorphism, however, did not differ between patients (THPP or GD) and controls. These results, therefore, do not support the presence of an association between the TCR beta/Bgl II RFLP and THPP nor with GD susceptibility. Finally, restriction analysis of DNA from our patients and normal controls using enzymes Bam HI, Eco RI, Pvu II and Taq I with the T cell receptor beta-chain gene did not show polymorphisms, and were therefore not informative.

The recurrence of recurrent membranous glomerulopathy in a renal transplant recipient: case report and literature review

We describe the first reported case of a renal transplant patient who had two consecutive recurrences of membranous glomerulopathy in his allografts. Both recurrences were detected 1 year posttransplant. The first transplanted kidney was a none of six antigen match and his second was a four of six antigen match. The patient required a second kidney transplantation within 2 years of detection of the first recurrence. The second allograft has functioned adequately for nearly 4 years after diagnosis. The case and literature review illustrate that membranous glomerulopathy can recur in both poorly and well-matched allografts, that recurrence does not always occur faster in the better-matched kidneys, that cyclosporine does not prevent recurrent disease, and that the course of recurrent membranous glomerulopathy is unpredictable.

A T cell receptor beta chain variable region polymorphism associated with radiographic progression in rheumatoid arthritis

OBJECTIVE

In rheumatoid arthritis (RA) genetic factors influence susceptibility to disease and progression. Identifying these genetic factors may give more insight into the aetiology and pathogenesis of this disease. Furthermore, if these genetic markers can predict progression in an early stage of disease, timely institution of more aggressive treatment in patients with a bad prognosis may help to prevent joint damage. Several studies have shown that HLA-DRB1 alleles are associated with RA, whereas others have indicated that genes not linked to the HLA complex are also involved. Candidates for such genes are the T cell receptor (TCR) alpha/beta genes.

METHODS

The association of a polymorphism in a TCR beta chain variable region gene (TCR-V beta 8) with both risk for RA and radiographic progression of joint disease was analysed after a three year follow up. A cohort of 118 white patients with a duration of disease shorter than one year at entry, and 110 white controls were typed for this (BamHI) TCR-V beta 8 polymorphism.

RESULTS

The distribution of the two alleles, 2.0 and 23.0 kb, was identical in patients and controls. Radiographic progression (modified Sharp method) after a three year follow up, studied in 111 patients, was significantly less in the group possessing the 2.0 kb allele (p = 0.03).

CONCLUSION

This does not confirm the reported association of the (BamHI) TCR-V beta 8 2.0 kb allele with RA. By contrast with previous findings in smaller studies, in the present study this 2.0 kb allele was protective against radiographic progression. Because well known prognostic variables in RA were corrected for, the findings indicate that the TCR-V beta 8 polymorphism studied is a new prognostic marker for this disease.

T-cell receptor gene polymorphisms in familial cardiomyopathy: correlation with anti-beta-receptor autoantibodies

Cardiac autoantibodies have been detected in a significant proportion of patients with dilated cardiomyopathy, but their relation to the pathogenesis of the disease remains unknown. This issue was examined in 41 members of an Ohio family with a heritable disorder of the cardiac conduction system and the myocardium. In 41.5% of all members studied, serum anti-beta-receptor antibodies were identified by a combination of techniques: ligand binding inhibition assay, enzyme-linked immunoassay of a beta 1-receptor peptide, and adenylate cyclase inhibition. The prevalence of autoantibodies was significantly higher (p < 0.01) in the affected (64.7%) than in the unaffected (25.0%) members. A 10.0 kb restriction fragment length polymorphism of the C beta region of the T-cell receptor gene was also overrepresented in affected males (60% versus 30% unaffected males, p < 0.01). In males, the presence of anti-beta-receptor antibodies was linked to the 10.0 kb C beta polymorphism. In affected males, a BlgII C alpha 2.14 kb polymorphism was also more frequent (62% versus 32% in unaffected, p < 0.01) and was linked to the presence of anti-beta-receptor antibodies. The distribution of haplotypes defined by V beta 8, C alpha, and C beta probes was significantly different between affected and unaffected (p < 0.04) and between antibody-positive and antibody-negative individuals. Since the major function of the T-cell receptor is the recognition of processed autoantigens, these results provide additional support for the role of autoimmunity in dilated cardiomyopathy.

Human T-cell receptor V alpha gene polymorphism

Polymorphism in the germline repertoire of T-cell receptor (TCR) variable alpha and beta (V alpha and V beta) genes could alter the relative abilities of individuals in a population to respond to particular antigens. Variation in the number of germline V alpha and V beta gene segments has been reported in wild mice and in different inbred mouse strains. A previous study of the human V beta gene germline repertoire failed to reveal a similar degree of polymorphism in the numbers of V beta gene segments. We have now carried out a survey of 10 different V alpha gene segment subfamilies containing approximately 23 V alpha gene segments in a panel of 120 unrelated individuals by hybridization and failed to find any evidence for V alpha repertoire polymorphism. To determine if significant germline polymorphism does occur in humans at the level of individual V gene segments, we determined the nucleotide sequences of eight copies of the V alpha 21 gene segment derived from seven unrelated individuals. Polymorphic differences between these sequences defined three different alleles. One of these alleles contains a frameshift mutation which would cause premature termination of the protein product. The presence of this null allele among the eight sequences determined suggests that functionally relevant germline polymorphism of human TCR V gene segments may occur by mechanisms other than gene duplication or deletion.

The contribution of non-MHC genes to susceptibility to autoimmune diseases

Genetic studies of experimental models of autoimmune diseases, including systemic lupus-like syndromes and organ-specific autoimmunity, provide major information on genetic control of autoimmune diseases. In addition to genes known to be linked to the major histocompatibility complex (MHC), these studies point to multiple genes located outside the MHC that influence the onset and the progression of autoimmune diseases. Identification of these genes and of their interrelationships is now a major task that will be facilitated by recent progress in molecular biology and gene mapping. Among candidate genes, antigen-receptor genes (i.e., immunoglobulin- and T-cell receptor genes) most likely contribute an important part of the autoimmune susceptibility in several of these animal models. Available linkage data suggest a similar involvement of these antigen-receptor genes in several human autoimmune diseases. In addition to a better understanding of pathogenic mechanisms associated with autoimmunity, the knowledge of these disease-predisposing genes is expected to permit a better classification of often complex syndromes as well as the design of new treatments.

An abnormal T cell repertoire in hypergammaglobulinaemic primary Sjögren's syndrome

T cell antigen specificity is determined by the products of the genes which encode the variable regions of their receptors. Of the T cell receptor (TCR) variable region gene products examined, only V beta 6.7a TCR-positive lymphocytes were reduced in primary Sjögren's syndrome patients with IgG1 hypergammaglobulinaemia compared with an age-, sex- and HLA-matched control population. The levels of V beta 6.7a T cells were also significantly reduced when these patients were compared with an age- and sex-matched but HLA-unmatched control group and non-tissue typed normal people of both sexes. Since published studies show no such abnormality in rheumatoid arthritis, systemic lupus erythematosus or other autoimmune diseases, this abnormality may reflect a pathogenic process specific to primary Sjögren's syndrome.

Germline repertoire of T-cell receptor beta-chain genes in patients with insulin-dependent diabetes mellitus

We have investigated the genotype and allelic distribution of germline restriction fragment length polymorphisms of the T-cell receptor beta chain, segment C beta, and two variable segments which are in linkage disequilibrium, V beta 8 and V beta 11, in 42 insulin-dependent diabetes mellitus (IDDM) patients and in 51 healthy blood donors used as controls. Recently, several works have reported contradictory results showing or not showing an association between polymorphic alleles of the C beta gene and diabetes type I. We found no significant differences in the allele, genotype, and haplotype distribution of the gene segments studied, between IDDM patients and control populations.

Association between a T cell receptor restriction fragment length polymorphism and systemic lupus erythematosus

The present study was designed to test the possibility that T cell receptor genes are associated/linked to those involved in systemic lupus erythematosus (SLE). Genomic DNA was isolated from 31 unrelated Caucasian SLE patients, 34 unrelated Caucasian normals, 5 multiplex American Caucasian SLE families, 9 multiplex Mexican SLE families, and 13 unrelated Mexican normals. The DNA was digested with Pst I, electrophoresed, and transferred to membranes by the Southern blot method. The blots were probed with a cDNA probe for the alpha chain of the T cell receptor. 13 polymorphic RFLP patterns were recognized. 1.3- and 3.0-kb band pairs were observed in 15 of 31 of American Caucasian patients and 4 of 34 American Caucasian controls (chi square, 8.81; P less than 0.002; relative risk, 7); there was no association of any RFLP pattern with Mexican SLE. The cDNA probe was cut with Rsa I, EcoR I, and Ava II into fragments corresponding to the V, J, C, and 3'UT regions. Only the fragment corresponding to the constant region reacted with the 1.3/3.0-kb band pair. These observations suggest that a genetic marker of the constant region of the alpha chain of the T cell receptor is associated with genes involved in SLE.

Allelic variations of human TCR V gene products

A central problem confronting the immune system is how to discriminate among vast numbers of antigens. Novel genetic ploys that aid the discriminative process, including complex gene rearrangements (in antibody and T-cell receptor (TCR) genes) and extensive allelic polymorphism (in major histocompatibility complex (MHC) genes), have been described. Recent evidence has suggested a further level of diversity; TCR V gene allelic variation. In this article David Posnett summarizes evidence in favour of this possibility and speculates on the possible functional consequences of TCR allelism.

Lack of association of T cell receptor beta-chain constant region polymorphism with insulin-dependent diabetes mellitus in Finland

Allelic polymorphism in the T cell receptor constant beta-chain gene region has been reported to be associated with autoimmune diseases, including insulin-dependent diabetes mellitus (IDDM). The present analysis of 164 children and adolescents with IDDM and 193 controls for BqlII polymorphism using a TcR-C beta cDNA probe revealed two allelic restriction fragments with sizes of 10.5 kb (U) and 9.6 kb (L). No particular association was observed between the RFLP genotypes and IDDM (UU 27% versus 31%; UL 53% versus 52%; and LL 20% versus 17%, in diabetic subjects and controls, respectively), nor were any differences found between patients with various HLA risk antigens. The frequency of heterozygotes was 52% in 63 DR3-positive diabetic subjects and 53% in 73 DR3-negative ones. The results do not support any involvement of the TcR constant region genes in susceptibility to IDDM.

Immunoglobulin heavy chain switch region gene polymorphisms in glomerulonephritis

Much evidence suggests that primary IgA nephropathy (IgAN) and idiopathic membranous nephropathy (MN) are immune complex mediated diseases. Moreover, genetic factors may play an important role in their pathogenesis. Recently, restriction fragment length polymorphisms (RFLPs) of the immunoglobulin heavy chain genes have been described which appear to associate with glomerulonephritis. We have studied RFLPs of the switch region of the IgM (S mu) and IgA1 (S alpha 1) heavy chain in MN and IgAN. DNA obtained from British Caucasoids with IgAN (N = 75), MN (N = 43), and normal controls (N = 73), was digested with the restriction enzyme Sac1, and studied using Southern blot techniques and hybridization with a 32P labelled DNA probe homologous to S mu. This probe detects RFLPs at the S mu and S alpha 1 loci. The genotypic and allelic frequencies of the S mu and S alpha 1 alleles in IgAN and MN was similar to normal controls. Caucasoid subjects with IgAN from Northern and Southern Europe (Finland and Italy, respectively) were also studied to determine whether an ethnic variation in genetic susceptibility to IgAN exists. The frequency of the S mu and S alpha 1 alleles was similar between the patient groups and their respective local healthy controls. These results do not support the recent findings of an association with RFLPs of the S mu and S alpha 1 loci in IgAN and MN, and suggest that the immunoglobulin heavy chain switch region genes are not important in conferring disease susceptibility to IgAN or MN.

Increased incidence of certain TCR and HLA genes associated with myasthenia gravis in Italians

In order to study the immunogenetics of myasthenia gravis (MG), we analysed the TCR and HLA-class II genes from Italian and Californian myasthenic patients. We investigated polymorphisms of the TCR using the full length cDNA probes pGA5 and the pT10 for the alpha and beta chains, respectively. The 6.3 kb and 2.0 kb polymorphic markers, revealed by the PssI enzyme and the alpha chain probe, were shown to be significantly associated with MG. Italian MG patients were HLA typed, and allele frequencies showed a significant association of DR3 and DQw2 with MG. The relative risk calculated for DR3 was 7.4. T-cell proliferative responses to peptides of the AchR alpha chain were also studied and no associations with TCR RFLP analysis or HLA-class II typing were observed.

Haplotyping the human T-cell receptor beta-chain gene complex by use of restriction fragment length polymorphisms

We have studied the genetic segregation of human T-cell receptor beta-chain (TCR beta) genes on chromosome 7q in 40 CEPH (Centre d'Etude du Polymorphisme Humain) families by using restriction fragment length polymorphisms (RFLPs). We constructed haplotypes from eight RFLPs by using variable- and constant-region cDNA probes, which detect polymorphisms that span more than 600 kilobases of the TCR beta gene complex. Analysis of allele distributions between TCR beta genes revealed significant linkage disequilibrium between only 6 of the 28 different pairs of RFLPs. This linkage disequillibrium strongly influences the most efficient order to proceed for typing of these RFLPs in order to achieve maximum genetic informativeness, which in this study revealed a 97.3% level of heterozygosity within the TCR beta gene complex. Our results should provide new insight into recent reports of disease associations with the TCR beta gene complex and should assist in designing future experiments to detect or confirm the existence of disease-susceptibility loci in this region of the human genome.

T-cell receptor beta-chain DNA polymorphism frequencies in healthy HLA-DR homozygotes

In view of numerous recent reports of T-cell receptor (TCR) beta-chain/disease associations with HLA-associated diseases, we tested the possibilities that associations might exist directly between these two gene complexes at the level of the germline DNA. We determined frequencies of five TCR-beta DNA polymorphisms in 33 HLA-DR2/2 homozygotes, 29 HLA-DR3/3 homozygotes and 42 HLA-DR4/4 homozygotes. The control population (n = 74) was chosen without "bias toward" their HLA-DR genes. We selected DR2, DR3 and DR4 homozygotes because they have been the most frequently involved in HLA-DR associated diseases. Our results indicate that the recent reports in the literature of TCR-beta/disease associations can not be explained by a significantly different distribution of TCR-beta genes in HLA-DR2+, -DR3+, or -DR4+ subpopulations. Our results also suggest that if co-evolution between TCR-beta and MHC haplotypes does exist, the selective pressures in recent generations have not been strong enough to significantly alter the germline TCR-beta gene frequencies in HLA-DR2+, -DR3+, or -DR4+ subpopulations.

T-cell receptor beta-subunit gene polymorphism and autoimmune disease

We have investigated the distribution of genotypes of a restriction fragment length polymorphism of the T-cell receptor beta-subunit gene in Caucasoid controls and patients with insulin-dependent diabetes mellitus, celiac disease, dermatitis herpetiformis, and idiopathic membranous nephropathy and also in South Indian controls and diabetics. We found no significant differences between the controls and patients with any disease in either ethnic group, a result which contrasts with previous reports of associations with both insulin-dependent diabetes mellitus and idiopathic membranous nephropathy. However, the most striking finding was a marked disparity between the genotype distribution in our Caucasoid control population and that previously reported by other investigators.

The T-cell receptor alpha, beta and gamma polymorphism in Japanese

Polymorphism in the genes encoding the alpha (alpha), beta (beta) and gamma (gamma) chains of the human T-cell receptors was analyzed both in population and family studies. Against twelve unrelated Japanese, several out of the 15 restriction endonucleases tested, revealed restriction fragment length polymorphism. The segregation of the polymorphic fragments were confirmed among 15 members of three families. In most of the cases paternal and/or maternal haplotypes could be assigned. By testing the polymorphic enzymes among the random healthy Japanese, the frequency of each polymorphic fragment was then determined. Although the polymorphism found in this study was similar to that reported in Caucasians, some differences were observed. Such differences are discussed. The restriction fragment length polymorphism in both population and family studies, derived from alpha, beta and gamma chains of the T-cell receptor found in this report, might be useful markers for genetic analysis of the T-cell function in relation to immunological disorders.

Immunoglobulin heavy chain switch region polymorphisms are not associated with type 1 diabetes

In order to ascertain whether the immunoglobulin heavy chain genes are important in the aetiology of Type 1 diabetes, we have used restriction fragment length polymorphism (RFLP) analysis of genomic DNA to study 148 Caucasoid subjects with Type 1 diabetes and 146 normal Caucasoid subjects. A DNA probe homologous to the switch regions for the IgM (S mu) and IgA1 (S alpha 1) genes when used in conjunction with the restriction endonuclease Sst I detects RFLPs at both these loci. There were no significant differences in phenotype or gene frequencies for the alleles of S mu or S alpha 1 in the patients when compared with control subjects; nor were there significant associations of S mu or S alpha 1 with HLA-DR type or gender.

Relation of mesangial IgA glomerulonephritis to polymorphism of immunoglobulin heavy chain switch region

We have investigated the switch regions of Ig heavy chain genes of patients with IgA glomerulonephritis (IgA-GN) using restriction fragment length polymorphism (RFLP) analysis. Genomic DNA from patients and controls was digested with the restriction endonuclease Sst I and transferred to nylon membranes using the Southern blot procedure and hybridized with a probe homologous to the switch region of the Ig C mu gene (S mu) which detects RFLPs in both S mu and the switch region of the Ig C alpha 1 gene (S alpha 1). A significant decrease in the frequency of the 2.6;2.1 kb heterozygous S mu phenotype was found in patients with IgA-GN (P = 0.003). With respect to the S alpha 1 region, there was a significant increase in the frequency of the 7.4 kb S alpha 1 phenotype (P = 0.002). In addition, a significant increase in the frequency of the 7.4 kb S alpha 1 allele was found (P = 0.0002). These results suggest that gene(s) within the Ig heavy chain loci may be important in the pathogenesis of IgA-GN.