Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0409974 (lupus)
 22,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Excessive production of pathogenic autoantibodies is one of the hallmarks of systemic lupus erythematosus (SLE). The mechanisms that underlie this excessive production are still unclear. Although there is considerable evidence to suggest that both T cells and B cells play an important role in the etiology of SLE, convincing abnormalities at the T cell receptor or immunoglobulin gene loci have not been demonstrated. In this regard, because cytokines play such a pivotal role in the inflammatory response, a defect in the immunoregulation of B cells by cytokines should be considered as possible contender in disease etiology. The hypothesis that is proposed here is that multiple defects mediated by cytokines are present in individuals with lupus and that both cytokine production and the response of B cells to cytokines may be defective. These abnormalities could then be a central factor in the etiology of systemic lupus erythematosus.
 ...
PMID:Cytokines play a central role in the pathogenesis of systemic lupus erythematosus. 149 23

Several of the heterogeneous clinical manifestations of systemic lupus erythematosus have been associated with specific autoantibodies. Associations between HLA class II antigens and autoantibodies to the ribonucleoproteins Ro(SSA) and La(SSB) have been reported in these patients. Because HLA class II molecules present antigen to T cell receptors (TCRs), we have searched for a TCR gene associated with the production of anti-Ro(SSA) antibodies. A pair of restriction fragment length polymorphisms (RFLPs), one of which hybridizes to the TCR constant region C beta 1 and the other to the C beta 2 gene, has been identified, suggesting these may be genotypic markers for an extended region of the TCR beta locus. This RFLP pair occurs in 76% of patients with Ro(SSA) precipitins, 84% of anti-Ro(SSA)-positive patients lacking La(SSB) precipitins, but only 41% of the patients lacking both precipitins (P = 0.0004). This disproportionate occurrence in a subset of lupus patients indicates that these RFLPs are not disease susceptibility markers, but rather are important markers for TCR genes whose products are involved in the production of anti-Ro(SSA) antibodies. The majority of patients who have these RFLPs and HLA class II antigens previously associated with the anti-Ro(SSA) response make this antibody, suggesting that interactions between products of these loci occur in response to Ro(SSA).
 ...
PMID:Anti-Ro(SSA) autoantibodies are associated with T cell receptor beta genes in systemic lupus erythematosus patients. 196 59

Our understanding of the immune mechanisms that lead to systemic lupus erythematosus has been greatly advanced by the availability of murine models which display both serological and clinical features of the human disease. Studies have demonstrated that CD4+ T cells are required for the full expression of disease in these mice. (NZB X NZW)F1 mice exhibit a lupus-like disease (elevated levels of IgG antinuclear antibodies and a fatal glomerulonephritis) that is not characteristic of either parent. At least three gene loci have been identified in NZW mice that could potentially contribute to a T cell-dependent autoimmune disease, including the T cell receptor alpha- and beta-chain gene complexes and the major histocompatibility complex (MHC). The NZW T cell receptor beta-chain complex appeared to be particularly unusual in that the C beta 1, D beta 2, and J beta 2 gene segments have been deleted. However, an analysis of (NZB X NZW)F1 X NZB back-cross mice revealed no association of disease expression with the presence of this allele. There was also no correlation of disease incidence with the presence of the NZW T cell receptor alpha-chain allele. In contrast, nearly 90% of the backcross mice with the NZW MHC expressed severe autoimmune disease compared with 12% of the mice that did not carry this haplotype. Additional studies strongly suggested that the gene(s) within the NZW MHC is the only dominant NZW genetic contribution to F1 disease. We also determined if self-reactive T cells are able to escape thymic tolerance in autoimmune New Zealand and MRLlpr/lpr mice. In nonautoimmune mice expressing I-E, T cells utilizing V beta 17a and V beta 11 encoded domains have been shown to be clonally eliminated in the thymus. Similarly, V beta 8.1+ and V beta 6+ T cells are tolerized in nonautoimmune mice expressing Mls-1a. These T cell subsets were quantified in the lymph nodes and spleens of (NZB X NZW)F1, (NZB X SWR)F1, and MRL-lpr/lpr mice before and after the development of lupus-like disease. The results indicate that peripheral T cells in these mice, including the massive CD4-, CD8- T cell population in lpr mice, have been modified by normal mechanisms of tolerance such that potential self-reactive V beta specificities have been eliminated in the thymus.
 ...
PMID:Self-reactive T cells in murine lupus: analysis of genetic contributions and development of self-tolerance. 257 38

In an attempt to determine whether genes involved in T cell antigen recognition are structurally abnormal and thereby promote murine systemic lupus, we analyzed the structural integrity of the D, J, and C region elements of the T cell receptor alpha and beta chain genes in all major lupus strains and several normal strains. Within the limits of restriction fragment length polymorphism analysis, all strains had an identical genomic organization, except the NZW mice, in which a deletion of the C beta 1-D beta 2-J beta 2 elements was found. Sequence analysis of NZW genomic elements containing this deletion placed its probable origin within the first exon of C beta 1, and extending to a complementary region within the first exon of C beta 2. The significance of this abnormality in the pathogenesis of systemic autoimmune disease remains to be determined.
 ...
PMID:Delineation of a defect in T cell receptor beta genes of NZW mice predisposed to autoimmunity. 300 67

Systemic lupus erythematosus (SLE) is a disease of immune dysregulation in which B cell hyperactivity and T cell deficiency are important characteristics. Sex factors also play a major role in the pathogenesis based on the physiologic effects of estrogen in promoting immunologic hyperactivity. Our findings suggest that a posttranscriptional mechanism is responsible for the functional interleukin 2 (IL-2) defect since transcription of the IL-2 message occurs after mitogenic stimulation. The proliferating cell in the MRL/lpr mouse model of lupus may be an immature T cell. The T cell receptor in these mice has a lower molecular weight than normal. This aberrant T cell receptor might be explained by a defect in glycosylation. The administration of estrogen to pregnant mice late in gestation results in offspring with a permanently altered immune system. These mice develop features of autoimmunity similar to those that occur spontaneously in genetically susceptible autoimmune mice. This phenomenon may have etiopathological significance for familial SLE.
 ...
PMID:Interleukin 2, T cell receptor and sex hormone studies in autoimmune mice. 311 77

In contrast to parental New Zealand Black (NZB) or New Zealand White (NZW) mice, (NZB x NZW)F1 mice exhibit a lupus-like disease characterized by high levels of immunoglobulin G (IgG) antinuclear antibodies in their serum and a fatal immune-complex glomerulonephritis. At least three gene loci have been identified in NZW mice that could potentially contribute to a T cell-dependent autoimmune disease, including the T cell receptor alpha- and beta-chain gene complexes and the major histocompatibility complex (MHC). The NZW T cell receptor beta-chain complex appeared to be particularly unusual in that the C-beta-1, D-beta-2, and J-beta-2 gene segments have been deleted. Approximately one half of (NZB x NZW)F1 x NZB backcross mice developed severe renal disease and elevated levels of IgG antibodies to double-stranded deoxyribonucleic acid and histone, suggesting that only one dominant gene or closely linked group of genes accounts for the NZW genetic contribution to F1 disease. Despite the extremely unusual nature of the NZW T cell receptor beta-chain gene complex, we found no association of disease expression with the presence of this allele in the backcross mice. There was also no correlation of disease incidence with the presence of the NZW T cell receptor alpha-chain allele. In contrast, nearly 90 percent of the backcross mice with the NZW MHC expressed severe autoimmune disease compared with 12 percent of the mice that did not carry this haplotype. Thus, the NZW MHC or gene(s) linked to this locus appears to be the only dominant NZW genetic contribution to F1 disease. Recent preliminary studies mapping genes that are located centromeric and telomeric to the NZW MHC suggest that the disease-associated gene(s) lies within the MHC.
 ...
PMID:Genetic contributions to lupus-like disease in NZB/NZW mice. 326 57

Unlike parental NZB or NZW mice, (NZB X NZW)F1 mice exhibit a lupus-like disease characterized by high serum levels of IgG antinuclear antibodies and a fatal immune-complex glomerulonephritis. At least three unlinked gene loci can be distinguished in NZW mice that conceivably contribute to a T cell-dependent autoimmune disease, including the MHC (H-2z) and the T cell receptor alpha and beta chain gene complexes. We undertook an (NZB X NZW)F1 X NZB backcross to determine the relative contribution of these NZW genes to lupus-like renal disease and autoantibody production in F1 mice. The incidence of severe renal disease and elevated levels of IgG antibodies to dsDNA and histone in the backcross mice was approximately half of that observed in (NZB X NZW)F1 mice. Furthermore, there was a strong correlation between the presence of the NZW H-2z haplotype and lupus-like disease in backcross mice. Approximately 90% of backcross mice with disease carried the NZW H-2z locus compared with 16% of mice without disease; nearly 90% of H-2d/z mice expressed severe autoimmune disease. In contrast, no association was apparent between the presence of the NZW T cell receptor alpha chain gene complex or beta chain gene complex and severe renal disease or autoantibody production. Thus, the NZW MHC or gene(s) linked to this locus appear to be the only dominant NZW genetic contribution to F1 disease.
 ...
PMID:The contribution of NZW genes to lupus-like disease in (NZB x NZW)F1 mice. 349 6

MRL-lpr/lpr mice spontaneously develop massive T cell lymphadenopathy, autoantibodies, and immune-mediated pathology. These mice are thought to be models of various human autoimmune diseases, including systemic lupus, Sjogren's syndrome, and rheumatoid arthritis. We have used cyclosporin A (CS-A) treatment as a tool by which the mechanisms of immune-mediated pathology might be dissected. CS-A was used because of its known preferential inhibition of T cell function and the marked expansion in MRL-lpr/lpr mice of an unusual L3T4-, Lyt-2-, 6B2+ T cell population. CS-A prevented lymphadenopathy and expansion of L3T4-, Lyt-2-, 6B2+ T cells in the peripheral lymph nodes, and also in the thymus. The increased expression of the c-myb and T cell receptor beta-chain genes associated with these unusual cells was also corrected. The finding of increased numbers of L3T4-, Lyt-2-, 6B2+ thymocytes in untreated mice suggests abnormal intrathymic differentiation in lpr/lpr mice, a defect that was corrected by CS-A. Treated mice had a marked decrease in arthritis and glomerulonephritis and significantly prolonged survival. These beneficial effects of CS-A occurred despite a lack of reduction in antibodies reactive with DNA, circulating immune complexes, rheumatoid factor titers, or immunoglobulin concentrations. These results demonstrate that the B cell hyperactivity of MRL-lpr/lpr mice can proceed without the T cell proliferative disease.
 ...
PMID:CS-A therapy in MRL-lpr/lpr mice: amelioration of immunopathology despite autoantibody production. 353 28

The contribution to systemic lupus erythematosus (SLE) of three lupus-associated polymorphisms (involving the C4A2 complement component, Humhv3005 and the T cell antigen receptor alpha chain gene) are investigated in 81 individuals from 14 multiplex SLE families, 41 unrelated lupus patients, and 88 unrelated healthy controls. The results show a strong association between C4A deletion and SLE in these families. While the current study confirms the previously reported association between hv3005 deletion and sporadic SLE, the study fails to support this association in familial SLE patients. Moreover, no correlation is detected between the occurrence of hv3005 deletion and C4A null alleles in lupus patients, suggesting that the effects of these genetic polymorphisms on predisposition to lupus are independent. The previously reported lupus-associated T cell receptor (TCR) alpha chain polymorphism is not detected in any of the individuals studied here. The combined data suggest that C4A null alleles predispose strongly to development of lupus, whereas the influence of hv3005 deletion is relatively weak. The results also suggest that contributions of weak susceptibility genes such as hv3005 to disease predisposition may be obscured by the effects of stronger genetic factors and thus need to be examined in patients lacking these factors.
 ...
PMID:Population and family studies of three disease-related polymorphic genes in systemic lupus erythematosus. 770 84

The production of potentially pathogenic anti-DNA autoantibodies in SLE is driven by special, autoimmune T helper (Th) cells. Herein, we sequenced the T cell receptor (TCR) alpha and beta chain genes expressed by 42 autoimmune Th lines from lupus patients that were mostly CD4+ and represented the strongest inducers of such autoantibodies. These autoimmune TCRs displayed a recurrent motif of highly charged residues in their CDR3 loops that were contributed by N-nucleotide additions and also positioned there by the recombination process. Furthermore, Th lines from four of the five patients showed a marked increase in the usage of the V alpha 8 gene family. Several independent Th lines expressed identical TCR alpha and/or beta chain sequences indicating again antigenic selection. 10 of these Th lines could be tested further for antigenic specificity. 4 of the 10 pathogenic anti-DNA autoantibody-inducing Th lines responded to the non-histone chromosomal protein HMG and two responded to nucleosomal histone proteins; all presented by HLA-DR molecules. Another Th line responded to purified DNA more than nucleosomes. Thus, these autoimmune Th cells of lupus patients respond to charged epitopes in various DNA-binding nucleoproteins that are probably processed and presented by the anti-DNA B cells they selectively help.
 ...
PMID:Structure and specificity of T cell receptors expressed by potentially pathogenic anti-DNA autoantibody-inducing T cells in human lupus. 786 Jul 35


1 2 3 4 5 6 7 Next >>