Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024141 (systemic lupus erythematosus)
 44,322 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several adhesion molecules and CD45RO have been reported to be upregulated on the cell surface of 'memory' T cells. Using triple-color flow cytometry, we compared the levels of typical 'memory' cell markers on peripheral blood T-cell subpopulations in a number of kidney transplant recipients, patients with systemic lupus erythematosus, newborn infants and healthy donors. CD45RO, VLA-beta 1 (CD29), VLA-5 alpha (CD49e), LFA-1 (CD11a/18), and CD2 were found to be closely coregulated on CD4+ T cells, while regulation of VLA-2 alpha (Cd49b), VLA-4 alpha (CD49d) and CD44 was quite discordant. In CD8+ T cells, by contrast, multiple subsets of 'memory'-type cells were distinguished. Unlike TCR alpha/beta T cells, which expressed either high or low levels of LFA-1, TCR gamma/delta cells all expressed high levels of LFA-1 (CD11a/CD18). Examination of T cells from kidney graft fine-needle aspiration biopsies during rejection revealed intragraft accumulation of 'memory'-type T cells expressing high levels of CD2 and LFA-1 (CD11a/CD18). Regarding peripheral blood T-cell subsets, differences between patients and healthy controls were only of a quantitative nature.
 ...
PMID:Discordant expression of LFA-1, VLA-4alpha, VLA-beta 1, CD45RO and CD28 on T-cell subsets: evidence for multiple subsets of 'memory' T cells. 752 37

Rt6 is a T cell-restricted GPI-anchored membrane protein and a member of the family of mono(ADP-ribosyl)transferases. One of the two murine Rt6 genes is deleted in NZW mice. This finding is reminiscent of the deletion of one of the TCR beta genes in the same mouse strain and it is an intriguing possibility that these gene deletions arose by a common genetic mechanism. The Rt6 locus retained by the NZW mouse (designated Rt6-1) is polymorphic among inbred strains of laboratory mice. The NZW mouse shows several strain-specific restriction fragment length variants in this Rt6 locus and five amino acid substitutions occur in the predicted native Rt6 polypeptide of the NZW mouse relative to the corresponding polypeptides of NZB and BALB/c mice. Whereas transcript levels of the two Rt6 genes appear to be normal in spleen and intestine of NZB mice, the corresponding tissues of NZW mice show reduced levels of transcripts from the Rt6 locus retained in this mouse strain. Moreover, reduced levels of Rt6 mRNA also occur in spleen and intestine of (NZB x NZW)F1 hybrid animals, indicating that F1 animals have inherited a dominant factor from the genetic background of the NZW mouse, resulting in low levels of Rt6 expression. It is conceivable that the alterations in the Rt6 genes of the NZW mouse and/or the factor(s) affecting defective Rt6 expression constitute part of the genetic contribution of the NZW mouse to the autoimmune lupus-like disease in (NZB x NZW)F1 animals.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Defects in the structure and expression of the genes for the T cell marker Rt6 in NZW and (NZB x NZW)F1 mice. 754 15

Allelic exclusion at the T cell receptor alpha locus TCR-alpha is incomplete, as demonstrated by the presence of a number of T lymphocyte clones carrying two expressed alpha chain products. Such dual alpha chain T cells have been proposed to play a role in autoimmunity, for example, because of a second TCR-alpha beta pair having bypassed negative selection by virtue of low expression. We examined this hypothesis by generating mice of various autoimmunity-prone strains carrying a hemizygous targeted disruption of the TCR-alpha locus, therefore unable to produce dual alpha chain T cells. Normal mice have a low but significant proportion of T cells expressing two cell-surface TCR-alpha chains that could be enumerated by comparison to TCR-alpha hemizygotes, which have none. Susceptibility to various autoimmune diseases was analyzed in TCR-alpha hemizygotes that had been backcrossed to disease-prone strains for several generations. The incidence of experimental allergic encephalomyelitis and of lupus is not affected by the absence of dual TCR-alpha cells. In contrast, nonobese diabetic (NOD) TCR alpha hemizygotes are significantly protected from cyclophosphamide-accelerated insulitis and diabetes. Thus, dual alpha T cells may play an important role in some but not all autoimmune diseases. Furthermore, since protected and susceptible NOD mice both show strong spontaneous responses to glutamic acid decarboxylase, responses to this antigen, if necessary for diabetetogenesis, are not sufficient.
 ...
PMID:Dual T cell receptor alpha chain T cells in autoimmunity. 756 98

To define age-associated alterations in the immune system at the molecular level, we have analyzed TCR V beta gene expression patterns at the fetal, neonatal, adult, and advanced ages of mice. In contrast to V gamma and VH genes, V beta genes rearranged without any preference related to their chromosomal organization. Endogenous superantigen-mediated clonal deletions were registered for the first time at the neonatal stage, presumably reflecting the late developmental appearance of these molecules. Such deletions, once established, were maintained throughout life with little, if any, leakage in this process. Furthermore, bone marrow transplantation and other studies indicated that an involuted thymus maintained its capacity to perform both its functions, i.e. positive and negative selection. Although overall V beta repertoires showed remarkable stability with advanced age, modifications in expression levels for some V beta, particularly those associated with the CD8 subset and presumably reflecting antigenic stimulation, were recorded. Mice with lupus and early-life thymic involution were fully capable of deleting endogenous superantigen-reactive V beta clones, and even lupus mice with a genetic defect in the apoptosis-promoting Fas gene were normal in this regard. The results indicate that, aside from some anticipated clonal expansions induced by antigenic stimulation, age-associated alterations in immune functions are not caused by any profound changes in the overall TCR repertoire.
 ...
PMID:V beta gene repertoire in the aging mouse: a developmental perspective. 759 12

Efforts to define the stromal architecture of thymic tissues of normal mice have used a panel of monoclonal antibodies (MTS series) to examine the localization of cell subtypes, including reagents that define thymic epithelial and stromal elements. Recent work with these MTS mAbs disclosed significant abnormalities in the thymic cortex of New Zealand mice including the appearance of medullary type epithelial cells in the cortical areas and the presence of epithelial free spaces or 'cortical holes'. To determine whether such abnormalities are unique to NZB mice or are found in other models of murine lupus, we examined the thymi of MRL/MP-lpr/lpr BXSB/MpJ Yaa, C3H/HeJ-gld/gld and C57BL/6 control mice. Thymi from all models of murine lupus showed dramatic alterations in the thymic microarchitecture. For example, staining with MTS10, a mAb which is specific for subcapsular and medullary epithelia, was decreased in the subcapsular and medullary regions. Moreover, there was increased staining in the thymic cortex, suggesting an abnormality in the localization of MTS10-reactive cells. Moreover, all three murine lupus strains demonstrated 'cortical holes' or cortical epithelial cell-free regions. By using MTS33, MTS35 and flow cytometry, both C3H/gld and BXSB/Yaa, but not MRL/lpr mice, showed decreased cortical thymocyte frequencies. Possible defects in the maturation of double-positive thymocytes to single-positive status in C3H/gld mice is implied by abnormally high levels of double-positive cells and low levels of single-positive cells. Finally, MRL/lpr thymocytes had lowered frequencies of CD3-4+8+ and increased levels of TCR-alpha/beta high cells.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Thymic microenvironmental abnormalities in MRL/MP-lpr/lpr, BXSB/MpJ Yaa and C3H HeJ-gld/gld mice. 761 45

Microbial superantigens (SAg), by virtue of their binding to TCR V beta elements and to class II MHC molecules on accessory cells, trigger T cell proliferation in a dose-dependent fashion. In contrast, SAg-induced T cell-dependent B cell differentiation occurs only at SAg concentrations that are orders of magnitude lower that those required for optimal mitogenesis (low-dose SAg). At optimal mitogenic doses (high-dose SAg), SAg-driven B cell differentiation does not ensue. In this report, we demonstrate that this dichotomy in SAg-driven B cell differentiation is due to the active inhibition of B cell differentiation by high-dose SAg. Such inhibition is not reversed by feeding cultures with fresh medium, with conditioned media, or with IL2 +/- IL4, and impaired B cell differentiation is observed in cultures containing purified T cells or CD4+ T cells + B cells, as well as in PBMC cultures. Although preincubation of either T cells or B cells with high-dose SAg impairs subsequent SAg-induced B cell differentiation, high-dose SAg is not toxic per se, since high-dose SAg does promote vigorous B cell differentiation in cultures of mitomycin C-treated T cells + B cells and does not inhibit T cell-independent B cell differentiation. No correlation exists between SAg-induced B cell surface expression of CTLA4 ligand and generation of Ig-secreting cells, but the dose of SAg does correlate with T cell-mediated SAg-dependent cytolysis of transformed B cell targets or autologous nontransformed activated B cell targets. B cell recovery from cultures stimulated with high-dose SAg is lower than that from cultures stimulated with low-dose SAg, whereas B cell apoptosis is greater in the former cultures than that in the latter cultures. T cells stimulated with high-dose SAg do not inhibit differentiation of activated B cells in the absence of physical contact between the T cells and the target B cells, supporting the notion of direct killing of activated B cells by T cells. The ability of low doses of SAg to promote B cell differentiation without generating biologically meaningful cytolytic activity and the ability of higher doses of SAg to modulate Ig production may have important pathogenetic and therapeutic ramifications for certain autoimmune disorders, such as systemic lupus erythematosus.
 ...
PMID:Differential human T cell-dependent B cell differentiation induced by staphylococcal superantigens (SAg). Regulatory role for SAg-dependent B cell cytolysis. 763 37

We studied the TCR/CD3 complex-mediated signal transduction pathway in freshly isolated T cells and T cell lines from patients with systemic lupus erythematosus (SLE). The peak and 5-min anti-CD3 mAb-mediated free intracytoplasmic Ca2+ concentration ([Ca2+]i) increase was statistically significant higher in fresh T cells from SLE patients than in control T cells. Increased CD3-mediated [Ca2+]i responses were observed in T cells from patients with SLE but not in T cells from other rheumatic diseases. Furthermore, significantly increased CD3-mediated [Ca2+]i responses were observed in T cell lines from SLE patients but not from controls. Although the [Ca2+]i response did not correlate with the global SLE disease activity or individual clinical manifestations, it was significantly higher in the group of patients who were not on treatment. Both CD4+ and CD8+ T cell subsets from peripheral blood cells and T cell lines displayed higher CD3-mediated [Ca2+]i responses than their normal counterparts. The peak of the response occurred earlier in the patient than in the normal group. The amount of Ca2+ that was released from the intracellular stores was higher in lupus than control T cells. The TCR/CD3-induced production of inositol phosphate metabolites in SLE cells was comparable with controls. The sarcoplasmic and endoplasmic reticulum Ca(2+)-ATPase inhibitor thapsigargin-induced [Ca2+]i response was similar in both SLE and normal T cells. Our experiments demonstrate for the first time a definite abnormality in the early steps of the TCR/CD3-mediated signal transduction pathway in T cells from SLE patients that involves increased release of Ca2+ from intracellular stores.
 ...
PMID:TCR/CD3 complex-mediated signal transduction pathway in T cells and T cell lines from patients with systemic lupus erythematosus. 763 73

PBMC proliferation in patients with SLE was assessed by incorporation of 3H-Tdr in an accessory cell-dependent response to anti-CD2 specific monoclonal antibody. The response was compared to monoclonal anti-CD3 and PHA response. There was a marked decrease in the response to anti-CD2 in SLE patients (9257 +/- 8543) than in normal controls (20619 +/- 15279) (P < 0.005). It was more obvious in 8 patients with less active and untreated disease, but not in 10 patients with less active or inactive disease. In contrast, no statistical difference was noted in the response to anti-CD3 and PHA between SLE patients and normal controls. We also examined the response of purified T cells to anti-CD2 and the response was depressed in SLE, but no marked decrease in the response to anti-CD3 was found in SLE patients. Our results demonstrate that SLE patients with active disease have T cells that respond poorly to CD2 activation, but that response via the CD3/TCR complex is essentially intact. It might be reflect intrinsic T cell defects in some SLE patients.
 ...
PMID:[CD2-mediated T-lymphocyte proliferation in patients with systemic lupus erythematosus]. 790 69

CD4+ T cells have been shown to be important in the development of disease in murine models of SLE. We compared the TCR V beta repertoires of young (healthy) and older (diseased) New Zealand hybrid mice as well as non-autoimmune strains to characterize changes in TCR usage associated with the development of disease. Despite large increases in the total number of splenic CD4+ T cells with age in diseased mice, we noted little skewing of the V beta repertoire. For example, diseased NZB.H-2bm12 mice failed to exhibit a significant change in the percentage of any V beta subset despite a fivefold increase in the number of CD4+ T cells. Strains without lupus-like disease, including NZB.H-2b mice, demonstrated no increase in CD4+ T cell numbers with age. Similar to NZB.H-2bm12 mice, (NZB x SWR)F, and (NZB x NZW)F1 mice showed disease-related increases in CD4+ T cell numbers, but no changes in V beta repertoire that could be linked to disease development. Differences in V beta usage between young autoimmune and non-autoimmune strains of mice matched for either MHC or background genes were consistent with genetic influences unrelated to disease. Overall, the heterogeneous repertoire of proliferating T cells provides evidence for polyclonal T cell expansion in murine models of lupus and suggests that activation either involves a multitude of conventional self-antigens or may be independent of the TCR. However, the requirement for specific class II MHC molecules suggests that this polyclonal T cell expansion is dependent on a much smaller and specific autoreactive response.
 ...
PMID:Evidence for polyclonal T cell activation in murine models of systemic lupus erythematosus. 791 14

T cells that recognize autoantigens may play a central role in the autoimmune response. We have previously shown that autoantigen-reactive T cells (CD4+) to U1-small nuclear ribonucleoprotein A were found in the PBMC of patients with systemic lupus erythematosus or mixed connective tissue disease. To reveal clonotypes of such T cells that spread to the periphery, T cell clonal accumulations and their TCR-beta chain variable gene usages in fresh PBMC from eight patients with mixed connective tissue disease were analyzed by a new method of single strand conformation polymorphism applying to TCR gene detection. The results revealed that the numbers of accumulated T cell clones (mean: 24.3 clones) were greater than the numbers of clones detected in healthy donors (mean: 4.0 clones). Frequently used V beta genes in these accumulated T cell clones were V beta 1, 3, 4, 5.2, 14, and 16. After the stimulation for these samples with the soluble recombinant U1-small nuclear ribonucleoprotein A protein, proliferative T cell responses were observed. We found that T cell clones expressing more restricted TCR V beta genes (1, 3, 5.2, and 14 families) accumulated in vitro. These results suggest that autoantigen-reactive oligoclonal T cell accumulations are present in the peripheral blood from systemic autoimmune disease patients.
 ...
PMID:Clonotype analysis of peripheral blood T cells and autoantigen-reactive T cells from patients with mixed connective tissue disease. 793 May 95


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>