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

Natural killer T (NKT) cells are a subset of T cells that share properties of natural killer cells and conventional T cells. They are involved in immediate immune responses, tumor rejection, immune surveillance and control of autoimmune diseases. Most NKT cells express both an invariant T cell antigen receptor and the NK cell receptor NK1.1, and are referred to as invariant NKT cells. This invariant T cell receptor is restricted to interactions with glycolipids presented by the non-classical MHC, CD1d. These NKT cells rapidly produce high levels of interleukin (IL)-2, IFN-gamma, TNF-alpha, and IL-4 upon stimulation through their TCR. Most also have cytotoxic activity similar to NK cells. NKT cells are involved in a number of pathological conditions, and have been shown to regulate viral infections in vivo, and control tumor growth. They may also play both protective and harmful roles in the progression of certain autoimmune diseases, such as diabetes, lupus, atherosclerosis, and allergen-induced asthma.
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PMID:Natural killer T cells: rapid responders controlling immunity and disease. 1583 65

CD1d-restricted NKT cells expressing invariant TCR alpha-chain rearrangements (iNKT cells) have been reported to be deficient in humans with a variety of autoimmune syndromes and in certain strains of autoimmune mice. In addition, injection of mice with alpha-galactosylceramide, a specific glycolipid agonist of iNKT cells, activates these T cells and ameliorates autoimmunity in several different disease models. Thus, deficiency and reduced function in iNKT cells are considered to be risk factors for the development of such diseases. In this study we report that the development of systemic lupus erythematosus in (New Zealand Black (NZB) x New Zealand White (NZW))F(1) mice was paradoxically associated with an expansion and activation of iNKT cells. Although young (NZB x NZW)F(1) mice had normal levels of iNKT cells, these expanded with age and became phenotypically and functionally hyperactive. Activation of iNKT cells in (NZB x NZW)F(1) mice in vivo or in vitro with alpha-galactosylceramide indicated that the immunoregulatory role of iNKT cells varied over time, revealing a marked increase in their potential to contribute to production of IFN-gamma with advancing age and disease progression. This evolution of iNKT cell function during the progression of autoimmunity may have important implications for the mechanism of disease in this model of systemic lupus erythematosus and for the development of therapies using iNKT cell agonists.
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PMID:Expansion and hyperactivity of CD1d-restricted NKT cells during the progression of systemic lupus erythematosus in (New Zealand Black x New Zealand White)F1 mice. 1600 72

NKT cells are a subset of regulatory lymphocytes characterized by co-expression of the NK cell receptor-CD161 and an invariant TCR-alpha chain (Valpha14-Jalpha28). They are most abundant in the liver, spleen, and bone marrow. NKT lymphocytes have been implicated in the regulation of autoimmune processes in both mice and humans. Activation of NKT lymphocytes leads to rapid amplification of either IFNgamma or IL4, endowing these cells with the capability to mediate both pro-inflammatory and anti-inflammatory immune responses. Activation of this subset of cells is associated with significant liver damage in the Concanavalin A immune mediated hepatitis model. Administration of CD1d ligand has a protective role in collagen-induced arthritis in mice. Disease amelioration was associated with a shift in the immune balance from a pathological Th1 type response towards a protective Th2 type response. In humans, patients with SLE, scleroderma, diabetes, multiple sclerosis, and rheumatoid arthritis have lower numbers of peripheral NKT cells. NKT lymphocytes promote tumor rejection in experimental models of tumor immunotherapy. In contrast, NKT lymphocyte-related anti-tumor activity is associated with pro-inflammatory Th1-type immune responses. NKT cells were shown to have a role in suppression of hepatocellular carcinoma (HCC) via immune regulation towards tumor derived antigens, and adoptive transfer of dendritic cells pulsed ex vivo with the same antigens. NKT lymphocytes are activated by interaction of their TCR with glycolipids presented by CD1d, a nonpolymorphic, MHC class I-like molecule expressed by antigen presenting cells, and also by hepatocytes. Several possible ligands for NKT cells have recently been suggested including CD1d bound Glucocerebroside. Glucocerebroside (GC, beta-glucosylceramide), a naturally occurring glycolipid, is a metabolic intermediate in the anabolic and catabolic pathways of complex glycosphingolipids. Its synthesis from ceramide is catalyzed by the enzyme glucosylceramide synthase. Inherited deficiency of glucocerebrosidase, a lysosomal hydrolase, results in Gaucher's disease. Patients with Gaucher's disease have altered humoral and cellular immune profiles and increased peripheral blood NKT lymphocytes. CD1d-bound glucocerebroside does not activate NKT cells directly, and may inhibit activation of NKT cells by alpha-GalCer. On the other hand, glucosylceramide-synthase deficiency was shown to lead to defective ligand presentation by CD1d, with secondary inhibition of NKT cell activation. Recent studies have suggested that a number of glycolipids, including GC, have an immune modulatory effect in several immune mediated disorders. The ability to alter NKT lymphocyte function in various settings and the potential application of natural glycolipids for treatment are discussed.
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PMID:Glycolipids as immune modulatory tools. 1710 Jun 36

Previous mapping studies have linked New Zealand Black (NZB) chromosome 4 to several lupus traits, including autoantibody production, splenomegaly, and glomerulonephritis. To confirm the presence of these traits, our laboratory introgressed homozygous NZB chromosome 4 intervals extending from either 114 to 149 Mb or 32 to 149 Mb onto the lupus-resistant C57BL/6 background (denoted B6.NZBc4S and B6.NZBc4L, respectively). Characterization of aged cohorts revealed that B6.NZBc4L mice exhibited a striking increase in splenic B1a and NKT cells in the absence of high titer autoantibody production and significant renal disease. Tissue-specific expansion of these subsets was also seen in the peritoneum and liver for B1a cells and in the bone marrow for NKT cells. Staining with CD1d tetramers loaded with an alpha-galactosylceramide analog (PBS57) demonstrated that the expanded NKT cell population was mainly CD1d-dependent NKT cells. The lack of both cellular phenotypes in B6.NZBc4S mice demonstrates that the genetic polymorphism(s) that result in these phenotypes are on the proximal region of NZB chromosome 4. This study confirms the presence of a locus that promotes the expansion of B1a cells and newly identifies a region that promotes CD1d-restricted NKT cell expansion on NZB chromosome 4. Taken together, the data indicate that neither an expansion of B1a cells and/nor NKT cells is sufficient to promote autoantibody production and ultimately, renal disease.
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PMID:Dissociation of the genetic loci leading to b1a and NKT cell expansions from autoantibody production and renal disease in B6 mice with an introgressed New Zealand Black chromosome 4 interval. 1723 10

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the emergence of autoreactive T cells. Humans and mice with SLE have reduced numbers of CD1d-restricted invariant natural killer T (iNKT) cells, suggesting a key role for these cells in its immunopathogenesis. This subset uses an invariant TCR constituted by Valpha14 Jalpha281 chains paired with some Vbeta domains. The regulatory role for iNKT cells in non-autoimmune mice was suggested by our previous results showing that aged Jalpha281 knockout (KO) mice produce anti-dsDNA. Here we show that old Jalpha281 KO mice have proteinuria and antibodies against dsDNA and cardiolipin. Histological analysis of Jalpha281 KO mice revealed glomeruli damage and deposition of C3c and IgG, mainly of the IgG3 subclass. In spleens of aged Jalpha281 KO mice there is an increase of activated marginal zone B cells. The evolution of lesions may depend on the age-associated increase of autoantibodies production, preferentially IgG3, mainly secreted by marginal zone B cells. Our results provide the first evidence of a lupus-like syndrome in non-autoimmune mice, supporting an age-related immunoregulatory role of Jalpha281+ cells, probably associated with the activation of marginal zone B cells.
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PMID:Immunoregulatory role of Jalpha281 T cells in aged mice developing lupus-like nephritis. 1727 90

Marginal zone (MZ) B cells contain a large number of autoreactive clones and the expansion of this compartment has been associated with autoimmunity. MZ B cells also efficiently transport blood-borne antigen to the follicles where they activate T cells and differentiate into plasma cells. Using the B6.NZM2410.Sle1.Sle2.Sle3 (B6.TC) model of lupus, we show that the IgM+ CD1d(hi)/MZ B-cell compartment is expanded, and a large number of them reside inside the follicles. Contrary to the peripheral B-cell subset distribution and their activation status, the intrafollicular location of B6.TC IgM+ CD1d(hi)/MZ B cells depends on both bone marrow- and stromal-derived factors. Among the factors responsible for this intrafollicular location, we have identified an increased response to CXCL13 by B6.TC MZ B cells and a decreased expression of VCAM-1 on stromal cells in the B6.TC MZ. However, the reduced number of MZ macrophages observed in B6.TC MZs was independent of the IgM+ CD1d(hi)/B-cell location. B7-2 but not B7-1 deficiency restored IgM+ CD1d(hi)/MZ B-cell follicular exclusion in B6.TC mice, and it correlated with tolerance to dsDNA and a significant reduction of autoimmune pathology. These results suggest that follicular exclusion of IgM+ CD1d(hi)/MZ B cells is an important B-cell tolerance mechanism, and that B7-2 signaling is involved in breaching this tolerance checkpoint.
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PMID:Intrafollicular location of marginal zone/CD1d(hi) B cells is associated with autoimmune pathology in a mouse model of lupus. 1860 47

Natural killer T (NKT) cells represent a unique T cell lineage. The NKT cells bearing an invariant TCR (iNKT cells) recognize a small variety of glycolipid antigens in the context of CD1d (non-classical MHC-I) presentation. CD1d-restricted iNKT cells play a regulatory role during an immune response by producing cytokines (IFN-gamma, and IL-4). The identification of alpha-galactosyl-ceramide (alpha-GalCer), a marine sponge derivative as a potent stimulator of iNKT cells has raised the potential of therapeutic iNKT cell activation. Invariant NKT cells have been implicated in several different autoimmune diseases in mice and humans, including systemic lupus erythematosus (SLE). Abnormalities in the number and functions of NKT cells have been observed in SLE patients and mouse strains genetically predisposed to lupus (MRL/lpr, NZB/W F1). Moreover, inverse correlation between the frequency of NKT cells and IgG levels has been observed. Elevated IgG levels in relatives of patients with lupus as well as in patients with lupus were associated with low frequencies of NKT cells. This review focuses on the potential roles of NKT cells in the pathogenesis of SLE. It summarizes recent advances in glycolipid therapy for murine lupus. First, it has been demonstrated, that repeated administration of alpha-GalCer to MRL/lpr mice alleviated inflammatory dermatitis but did not influence kidney disease. Treatment of NZB/W mice with alpha-GalCer resulted in amelioration of SLE symptoms in young mice, but treatment of older animals resulted in disease exacerbation. The effects of NKT cell activation using alpha -GalCer, on disease progression, were influenced by a variety of parameters, including the genetic background of mice, the alpha -GalCer dose, number of injections and the stage of the disease process when treatment was performed. Manipulation of NKT cells in the human system may be a promising treatment alternative for the future, however possible deleterious effects have to be carefully investigated first.
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PMID:Role of invariant natural killer T (iNKT) cells in systemic lupus erythematosus. 1869 Oct 38

Type 1 NKT cells play a critical role in controlling the strength and character of adaptive and innate immune responses. We have previously reported deficiencies in the numbers and function of NKT cells in the NOD mouse strain, which is a well-validated model of type 1 diabetes and systemic lupus erythematosus. Genetic control of thymic NKT cell numbers was mapped to two linkage regions: Nkt1 on distal chromosome 1 and Nkt2 on chromosome 2. Herein, we report the production and characterization of a NOD.Nkrp1(b).Nkt2b(b) congenic mouse strain, which has increased thymic and peripheral NKT cells, a decreased incidence of type 1 diabetes, and enhanced cytokine responses in vivo and increased proliferative responses in vitro following challenge with alpha-galactosylceramide. The 19 highly differentially expressed candidate genes within the congenic region identified by microarray expression analyses included Pxmp4. This gene encodes a peroxisome-associated integral membrane protein whose only known binding partner is Pex19, an intracellular chaperone and component of the peroxisomal membrane insertion machinery encoded by a candidate for the NKT cell control gene Nkt1. These findings raise the possibility that peroxisomes play a role in modulating glycolipid availability for CD1d presentation, thereby influencing NKT cell function.
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PMID:Congenic analysis of the NKT cell control gene Nkt2 implicates the peroxisomal protein Pxmp4. 1871 12

An increasing body of evidence suggests that CD1d-restricted invariant natural killer T (iNKT) cells play an important immunoregulatory role in a variety of autoimmune diseases in both humans and mouse models. Their role in systemic lupus erythematosus (SLE), however, is not fully determined, as SLE mouse models have yielded conflicting results demonstrating both a protective function and a pathogenic role. The reduced frequency of iNKT cells in peripheral blood of lupus patients supports the idea of a protective role for these cells in the immunopathology of SLE. Therapeutic approaches using glycolipids provide a promising tool to correct numerical iNKT cell deficiencies and to modulate their function. This review highlights the potential role of iNKT cells in lupus immunopathology and summarizes recent studies concerning iNKT cells in SLE patients, lupus-prone murine models and glycolipid therapy.
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PMID:The role of iNKT cells in the immunopathology of systemic lupus erythematosus. 1975 83

Signaling lymphocytic activation molecule (SLAM)-associated protein (SAP) is an adaptor molecule containing a Src homology 2 (SH2) domain. SAP is expressed in T cells and natural killer (NK) cells and binds to the cytoplasmic domains of SLAM family receptors, resulting in the subsequent recruitment of Fyn. The SAP (SH2D1A) gene is located on the X chromosome and is responsible for X-linked lymphoproliferative disease, characterized by higher susceptibility to Epstein-Barr virus infection. The SAP-mediated signal is not only essential for the development of NKT cells, i.e. unconventional CD1d-restricted T cells with invariant Valpha14 T cell receptors, but also for the regulation of the function of NK cells and conventional T cells. The role of SAP-mediated signaling in the induction of autoimmune diseases has been analyzed using animal models such as lupus, hepatitis, and graft-versus-host disease and is considered important in their pathogenesis in humans. In this review we highlight the current findings on SAP-mediated signaling in hematopoietic cells and discuss its importance in autoimmune diseases and immunological disorders.
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PMID:Role of SLAM-associated protein in the pathogenesis of autoimmune diseases and immunological disorders. 2004 47


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