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

T-cell-enriched populations obtained from lymph nodes (LNs) of 4-month-old MRL/Mp-lpr/lpr (MRL-lpr), C3H/HeJ-lpr/lpr (C3H-lpr), and C3H/HeJ-gld/gld (C3H-gld) mice were studied for the expression of B220, L3T4, and Lyt 2 antigens. A new B220+ L3T4+ phenotype was demonstrated in T-cell populations of these mice by two-color flow cytometry with phycoerythrin-conjugated monoclonal antibodies (MoAb) to L3T4 and FITC-anti-B220 MoAb. The generation of the T subset was apparently under the influence of the lpr or gld gene, since it could not be demonstrated in T-cell-enriched populations of MRL/Mp- +/+ and normal C3H mice. The expression level of L3T4 antigen on the T subset was lower than that on B220- L3T4+ cells, while the level of B220 antigen was similar to that of B220+ L3T4- or B220+ Lyt 2- cells. The B220+ L3T4+ phenotype appeared in LNs and spleens, but not in thymuses, of MRL-lpr mice as early as 2 months of age. Its proportion to whole LN T cells at this age was equivalent to that observed in 4-month-old mice. Functional studies on FACS-sorted cell populations revealed that the T subset similar to B220+ L3T4- cells possessed deficiencies in the IL-2-IL-2 receptor system. The appearance of the T subset with an intermediate phenotype and its functional defects suggests that lpr and gld genes in these autoimmune mice exert their influences on the ontogeny and function of L3T4+ T cells and contribute to the induction of early lupus.
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PMID:Ontogeny and function of B220+ L3T4+ T-cell subset of MRL/Mp-lpr/lpr mice. 245 58

Cultured human keratinocytes were lysed by activated PBMC in a 4-h 51Cr release assay. PBMC were activated by incubation with 50 U/ml of rIL-2 for 4 days. The cytotoxic precursors were found to be NKH1+ and included both CD2+ and CD2- phenotypes. This cytotoxicity was not genetically restricted, as cells killed both allogeneic and autologous keratinocytes without priming. Cytotoxicity was blocked by pre-incubation of effector cells with mAb against LFA-1 alpha-(TS1/22) and beta-chains (TS1/18), but not by antibodies directed against CD4, CD8, or leukocyte common Ag (T200) suggesting that LFA-1 is an important interactive molecule in this cytotoxicity. IFN-gamma is reported to upregulate ICAM-1, the ligand for LFA-1. Pre-treatment of target keratinocytes with IFN-gamma was also found to greatly increase the sensitivity of keratinocytes to lysis. This increased sensitivity to lysis was blocked by anti-LFA-1 and anti-ICAM-1, but not by anti-DR (L243), and thus was not the result of increased DR expression. Such treated targets were lysed at low levels (15 to 18%) by an Ag-specific CD8+ cytotoxic clone as well as a T cell line derived from a skin lesion of allergic contact dermatitis. In contrast, control keratinocytes were only sensitive to IL-2-activated PBMC as described above. The above findings may be relevant to a variety of conditions in which epidermal damage is associated with lymphocytic infiltrate. These conditions include graft-vs-host disease, erythema multiforme, and lupus erythematosus. DR+ keratinocytes, which may be a marker for IFN-gamma are also found in the above conditions. It is suggested that epidermal pathology may be mediated by non-specific cytotoxicity induced in the course of an immune response.
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PMID:Non-specifically activated human peripheral blood mononuclear cells are cytotoxic for human keratinocytes in vitro. 246 92

It is generally accepted that human Th cells express the surface glycoproteins CD4 and alpha/beta-chain heterodimer of the TCR whereas cytotoxic/suppressor cells are usually CD8+ and alpha/beta TCR+. Another minor set of T cells found in the periphery are CD4-/CD8- (double negative) and express the gamma/delta TCR; these cells can manifest MHC-restricted or nonrestricted cytotoxicity but no helper function. Herein we describe the existence of an unusual Th population in the peripheral blood of humans that are CD4-/CD8- and alpha/beta TCR+. These double-negative Th were markedly expanded in patients with the autoimmune disease SLE and along with CD4+ Th, they induced production of the pathogenic variety of anti-DNA autoantibodies that are IgG in class and cationic in charge. The cationic anti-DNA antibodies induced by the Th were markedly restricted in spectrotype indicating that an oligoclonal population of B cells were committed to produce the pathogenic autoantibodies in active lupus. IL-2-dependent T cell lines were also derived from the patients with active lupus nephritis but the majority of those T cell lines lacked pathogenic autoantibody-inducing capability. Only 4 out of 42 T cell lines from a lupus patient could induce the production of cationic IgG class anti-DNA autoantibodies. The phenotypes of the pathogenic autoantibody-inducing Th lines were similar to the Th subsets: CD4+, alpha/beta TCR+ or CD4-/CD8-, alpha/beta TCR+. These studies suggest that production of pathogenic autoantibodies in human lupus is mediated by mechanisms that are distinct from the generalized, nonspecific polyclonal B cell hyperactivity that leads to excessive production of natural autoantibodies.
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PMID:T cell receptor alpha/beta expressing double-negative (CD4-/CD8-) and CD4+ T helper cells in humans augment the production of pathogenic anti-DNA autoantibodies associated with lupus nephritis. 252 44

Our results provide important evidence that IL-2 receptor bearing cells are required for undesired immune reactions involved in autoimmunity, allograft rejection and nephritogenic processes. Administration of anti-IL-2 receptor monoclonal antibodies prolonged vascularized heart allograft survival across major histocompatibility barrier in mice and rats and renal monkey grafts. Indeed, several grafts survived indefinitely, although the antibody was administered only for the first 10 days post-transplantation. Rejection of the remaining grafts may well reflect inadequate dosage of antibody; dose-response studies have not been performed to date. In addition to preventing rejection, delayed treatment with anti-IL-2R monoclonal antibody was shown to reverse ongoing rejection in other recipients of heart allografts. Such long-term engraftment following cessation of therapy makes it unlikely that anti-IL-2R treatment prolongs graft survival by pharmacologic blockade of the IL-2R. Furthermore, exogenous IL-2 does not diminish the beneficial effects of anti-IL-2R antibody therapy in rodents. Whether or not such prolonged graft survival represents deletion of the responding T cell clones is a subject of current investigation. Results in a delayed-type hypersensitivity model indicate that complement fixation, is required to achieve optimal immunosuppression. Moreover, only anti-receptor antibodies that block IL-2 binding mediate optimal immunosuppression. Passive transfer experiments clearly prove that immediate post-transplant courses of anti-IL-2R monoclonal antibody spares suppressor T cells. In rodent models, delayed type hypersensitivity and lupus and diabetic autoimmunity are prevented by anti-IL-2R treatment. Finally, the availability of monoclonal antibodies directed against the human IL-2R provides an opportunity to extend this principle to clinical transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Toward more selective therapies to block undesired immune responses. 265 66

Splenocytes of MRL/l mice, one of the murine lupus strains, were found to produce a factor(s) which potentiates antibody formation. This factor was produced by splenocytes of young MRL/l mice and cell-sorting experiments by flow cytometry indicated that Thy 1.2+ cells were producing the factor. The approximate molecular weight of the factor was found to be 35,000-45,000 daltons and its pI value was between 3.3 and 3.8. It was also demonstrated that this factor is distinct from interferons, interleukins (IL-1, IL-2, IL-3) and B cell differentiation factors.
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PMID:A factor potentiating antibody formation spontaneously produced by splenic T cells of MRL/MP-lpr/lpr mice. 349 82

The autoimmune manifestations of MRL/Mp-lpr/lpr(MRL/l), a murine model of systemic lupus erythematosus (SLE), were alleviated by administering 1 microgram cholera toxin (CT) every 14 days. The beneficial effects were: (i) significant prolongation of survival time, (ii) prevention of lymphadenopathy, (iii) improvement of T cell mitogenic responses and suppression of a B cell mitogenic response, (iv) decrease in serum anti-DNA and anti-Sm antibodies, (v) increase in IL-2 production by stimulation of spleen cells with concanavalin A (Con A). It is possible that CT may be effective for treatment of murine lupus nephritis by modulating polyclonal lymphocyte activation. This type of immunomodulation may pave the way toward treatment of lupus and other autoimmune diseases.
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PMID:Treatment of autoimmune MRL/Mp-lpr/lpr mice with cholera toxin. 350 Aug 17

Three independent mutations involving the apoptosis-1 (APO-1)/Fas receptor or its putative ligand have led to lupuslike diseases associated with lymphadenopathy in different strains of mice. To determine whether humans with SLE also have a defect in this apotosis pathway, we analyzed the expression of APO-1 on freshly isolated blood mononuclear cells and on lymphocytes activated in vitro using flow cytometry and the monoclonal antibody anti-APO-1. Significantly higher level of APO-1 expression were detected on freshly isolated peripheral B cells and both CD4+ and CD8+ T lymphocyte populations obtained from lupus patients when compared with normal controls (P < 0.001). Almost 90% of the cells that stained positive for APO-1 also expressed the CD29 antigen, suggesting that APO-1 was upregulated after lymphocyte activation in vivo. No defect in APO-1 regulation was detected after activation of SLE T (with anti-CD3) or B (with Staphylococcus aureus Cowan 1) lymphocytes in the presence of IL-2 in vitro. Similarly, the anti-APO-1 antibody induced apoptosis in 74 +/- 5% of activated SLE T cells in vitro compared with 79 +/- 6% of the normal controls (P > 0.05). These results reveal that, while APO-1/Fas may play an important role in the regulation of lymphocyte survival in SLE, no consistent defect in the expression or function of the receptor could be detected in these studies.
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PMID:The apoptosis-1/Fas protein in human systemic lupus erythematosus. 751 Jul 16

CD4+ cells are thought to play a significant role in the development of lupus-like disease in a variety of autoimmune disease-prone mouse strains. In one such strain, BXSB/MpJScR, male mice develop severe lupus-like symptoms early in life but females do not. In this study, splenic CD4+ cells from male and female BXSB mice were evaluated for age-related changes in: 1) membrane expression of CD4+ cell subset markers (1, 2, and 4 mo) and activation Ags (4 mo) and 2) the capacity to proliferate and produce cytokines (4 mo) in response to polyclonal stimuli. CD4+ cells from females of all age groups and from younger males were predominantly CD44lo, CD45RBhi, MEL-14hi, and 3G11hi (phenotypes associated with naive T cells). In contrast, 4-mo-old males were predominantly CD44hi, CD45RBlo, MEL-14lo, and 3G11lo (phenotypes associated with activated/memory T cells). Furthermore, an increased constitutive expression of the activation Ags RL388, IL-2R, and TfR was observed in CD4+ cells of 4-mo-old male BXSB mice in comparison with age-matched females. In 3-day cultures, purified CD4+ cells from 4-mo-old males proliferated significantly less than cells from age-matched females in response to plate-bound anti-CD3 epsilon (2C11i). The reduced proliferation was restored in large part by PMA and ionomycin. CD4+ cells from older males generally produced increased amounts of IFN-gamma and IL-4 and significantly less IL-2 than age-matched females in response to either stimulus (IL-2 mRNA was also decreased in response to 2C11i). Taken together, these studies suggest that profound phenotypic and functional changes occur with age in the CD4+ cells of male BXSB mice that are indicative of an activated state.
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PMID:Maturational changes in CD4+ cell subsets and lymphokine production in BXSB mice. 751 69

Treating activated CD4+ T cells with DNA methyltransferase inhibitors modifies gene expression and induces autoreactivity. Adoptive transfer of viable polyclonal autoreactive cells causes a lupus-like disease, most likely because of one or more effector functions expressed by the autoreactive cells. However, the number of potential effector mechanisms expressed by polyclonal cells is large. To more readily identify responsible mechanisms, we asked if autoimmunity can be induced by using the conalbumin-reactive, cloned Th2 cell line D10.G4.1, treated with 5-azacytidine (5-azaC) or procainamide (Pca). Treated, but not untreated, cells responded to syngeneic APCs without Ag, overexpressed LFA-1, spontaneously lysed syngeneic macrophages, and secreted relatively large amounts of IL-6, small amounts of IL-4, and no detectable IL-2 nor IFN-gamma. Adoptive transfer of treated, but not untreated, cells induced a severe immune complex glomerulonephritis, pulmonary alveolitis, central nervous system abnormalities including fibrinoid necrosis, karyorrhexis, and meningitis, and bile duct proliferation with periportal inflammatory cell infiltration resembling primary biliary cirrhosis. Anti-ssDNA, anti-dsDNA, and anti-histone Abs were also found. These experiments demonstrate that modification of this cloned T cell line with DNA methyltransferase inhibitors is sufficient to cause an autoimmune disease, with features of lupus as well as autoimmune liver disease. The results also raise the possibility that macrophage lysis, IL-6 secretion, and LFA-1 overexpression could contribute to the disease process. This system may be useful in testing the role of these and other pathologic mechanisms in the development of specific autoimmune lesions.
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PMID:Mechanism of drug-induced lupus. I. Cloned Th2 cells modified with DNA methylation inhibitors in vitro cause autoimmunity in vivo. 753 91

Groups of female MRL/MpJ-lpr/lpr mice received either saline or FK506 (tacrolimus; 2 mg/kg intraperitoneally) three times weekly, cyclophosphamide (CY; 20 mg/kg) once monthly, or both drugs from 8 weeks of age. Median survival for untreated and CY-treated mice was 26 weeks, and for FK506- and FK506 + CY-treated groups was > or = 44 weeks. Severity of skin lesions and lymph node hyperplasia was markedly reduced by the drug combination, whereas either drug alone was less effective. FK506 or CY alone delayed the onset of proteinuria, but by 24 weeks all of these animals were positive. In contrast, drug combination reduced the prevalence of proteinuria to < or = 60% throughout the 44 weeks of study. Sequential monitoring of peripheral blood lymphocytes revealed that combination therapy but not monotherapy markedly reduced the proportion of atypical CD3+ B220+ and CD3+CD4-CD8- T cells. Neither FK506 nor CY affected the reduction in IL-2 and IL-4 mRNA levels observed in lymph nodes of diseased animals compared with normals. Although the drug combination also did not affect IL-2 mRNA levels, IL-4 mRNA transcripts were increased six-fold compared with saline-treated controls. IL-10 and interferon-gamma (IFN-gamma) mRNAs were induced by FK506, CY and by the drug combination. Serum levels of anti-dsDNA antibodies were reduced in all treatment groups. These data demonstrate improved efficacy of combined T and B cell-directed immunosuppression in murine lupus, associated with marked inhibition of atypical T cells and selective augmentation of IL-4 within the affected lymphoid tissue.
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PMID:Combined effects of FK506 (tacrolimus) and cyclophosphamide on atypical B220+ T cells, cytokine gene expression and disease activity in MRL/MpJ-lpr/lpr mice. 753 8


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