Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0003864 (arthritis)
 69,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Borrelia burgdorferi-infected mice develop acute arthritis that undergoes Ab-mediated resolution. To further investigate the role of B. burgdorferi-specific Abs in Lyme borreliosis, CD40 ligand-deficient (CD40L-deficient) mice were infected with B. burgdorferi. The development and regression of arthritis were similar in CD40L-deficient and control mice. Although CD40L-deficient mice have defects in Ig class switching, infected CD40L-deficient mice developed B. burgdorferi-specific IgG2b Abs. Moreover, the transfer of serum from B. burgdorferi-infected CD40L-deficient animals prevented infection in severe combined immunodeficient mice. These data show that B. burgdorferi-infected CD40L-deficient mice are capable of producing Abs that are protective, despite the inability of these mice to mediate T-dependent immune responses.
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PMID:Protective antibodies in murine Lyme disease arise independently of CD40 ligand. 868 1

TNF plays a pivotal role in the pathogenesis of a broad spectrum of infectious, inflammatory, and autoimmune diseases. In addition to the secreted, mature 17 kD form, TNF exists as a bioactive precursor 26 kD transmembrane protein. Transmembrane TNF signaling has been directly associated with specific immune mechanisms, including the contact-dependent lymphocyte and monocyte-mediated cell killing and the CD40 ligand-independent, T cell-mediated polyclonal B cell activation. In previous studies, we have reported that mice expressing 3'-UTR modified human TNF transgenes develop chronic inflammatory polyarthritis with a 100% phenotypic penetrance and timed disease onset. In additional experiments, we have also shown that high-level expression of human TNF in lymphoid cells of transgenic mice results in both local (thymic hypoplasia) and systemic (ischaemia, tissue necrosis, and wasting) TNF-mediated pathology. In this study we show that transgenic mice expressing a T cell-targeted membrane-associated mutant human TNF alpha protein are displaying only local TNF-mediated pathologies, ranging from lymphoid tissue derangements to proliferative synovitis and chronic inflammatory arthritis. These results demonstrate that in vivo, at least part of the pathogenic activities of TNF alpha may be assigned to the functioning of its uncleaved, membrane-associated form.
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PMID:Transmembrane TNF is sufficient to induce localized tissue toxicity and chronic inflammatory arthritis in transgenic mice. 873 89

The balance between Th1 and Th2 cells regulates the choice between inflammatory and antibody-mediated immune responses. To an increasing extent this balance is thought to involve the participation of antigen-presenting cells, rather than the entirely autonomous activity of T cells and their cytokines. Here we survey current opinion concerning the working of this balance, and its condition in rheumatoid arthritis and the other inflammatory arthritides. The contrast between Lyme arthritis and reactive arthritis is particularly illuminating, since one is triggered by extracellular and the other by intracellular infection. We describe current approaches to the modulation of this balance. Guided by the principles that genetic polymorphism is likely to identify relevant genes, that any cytokine gene picked up by a virus must matter and that natural immunosuppressive activity at mucosal surfaces should be worth exploiting, we identify as particularly worthy of attention: (i) IL-10, (ii) inhibitors of IL-12 production, (iii) inhibitors of CD40 ligand expression and (iv) oral and nasal tolerance. Other protective T cell subsets are touched on, and the impact of oligonucleotide arrays mentioned.
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PMID:Modulating the Th1/Th2 balance in inflammatory arthritis. 983 76

Tetrandrine, a purified traditional Chinese medicinal herb that acts as an immunosuppressant and a Ca2+ channel blocker, has been clinically used to treat patients with arthritis, silicosis and hypertension. Since T cells play a critical role as autoreactive and pathogenic population in autoimmune diseases, in this study, we examined the immunosuppressive effect of tetrandrine on human peripheral blood T cells. We showed that tetrandrine inhibited phorbol 12-myristate 13-acetate (PMA) + ionomycin-induced T cell proliferation, interleukin-2 secretion and the expression of the T cell activation antigen, CD71. Further investigation of the molecular mechanism demonstrated that tetrandrine inhibited the expression of the protein kinase C-dependent interleukin-2 receptor alpha chain and CD69 but not the expression of the Ca2+-dependent CD40 ligand and CD69. Interestingly, when tetrandrine and cyclosporin A were added together, significant synergism in the suppression of T cell activation was observed. Moreover, of the several tetrandrine analogues studied, hernandezine was the most potent inhibitor of protein kinase C signaling events. These results also suggest that the protein kinase C-inhibitory capacity of tetrandrine and its analogues may not be associated with their function as Ca2+ channel blockers. Lastly, we showed that, within therapeutic concentrations, tetrandrine and its analogues could induce cellular apoptosis, which is defective in autoimmune diseases. In conclusion, our findings provide novel information about the molecular mechanism of the immunosuppressive effect of tetrandrine and its analogues in human peripheral blood T cells.
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PMID:Plant alkaloid tetrandrine downregulates protein kinase C-dependent signaling pathway in T cells. 1007 15

Hyper-IgM syndrome (HIM) is a rare immunodeficiency disorder that has been associated with the development of symptoms and clinical features characteristic of rheumatoid arthritis (RA). We describe a patient with HIM and severe erosive arthritis with prominent nodules in the absence of detectable serum rheumatoid factor. Because HIM results from defects in either T cell CD154 (CD40 ligand) expression or abnormal CD40 signaling, the molecular basis of the patient's disease was analyzed. Activated CD4+ T cells failed to express surface CD154 protein, and molecular analysis of CD154 complementary DNA revealed a nucleotide transversion resulting in the nonconservative amino acid substitution G-D at amino acid 257. This case indicates that defective CD154-dependent CD40 signaling can be associated with susceptibility to a severe inflammatory arthritis that has both similarities to and differences from idiopathic RA.
Arthritis Rheum 1999 Jun
PMID:An aggressive form of polyarticular arthritis in a man with CD154 mutation (X-linked hyper-IgM syndrome). 1036 25

CD40 ligand, a type II transmembrane protein recently renamed CD154, was originally considered restricted to activated T lymphocytes, functioning as a mediator of T cell-dependent B cell activation, proliferation, and differentiation. However, the spectrum of CD154 expression and function has broadened considerably during recent years, establishing new roles as a central mediator of immunity and inflammation for this member of the tumor necrosis factor (TNF) gene superfamily. The emerging picture indicates that ligation of the receptor CD40 via CD154, most potently in its trimeric form, functions in two ways. CD154 modulates physiologic processes, such as T cell-mediated effector functions and general immune responses required for appropriate host defense, but also triggers the expression of pro-inflammatory mediators, such as cytokines, adhesion molecules, and matrix degrading activities, all of which are associated with the pathogenesis of chronic inflammatory diseases, e.g., autoimmune disorders, arthritis, atherosclerosis, and cancer. Accordingly, CD40/CD154 interactions have advanced as a potential therapeutic target for these diseases, whereby two opposing strategies, interruption as well as enhancement of CD40 signaling, are explored for beneficial outcomes.
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PMID:CD154 (CD40 ligand). 1085 99

Much debate has focused on the relative importance of interleukin 1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) in the pathophysiology of rheumatoid arthritis (RA). The production of these cytokines by synovial macrophages is tightly regulated by cell-cell contact with T cells. During this contact, several surface molecules are implicated in contact mediated cytokine production, including CD40 ligand, CD11b/c, and CD69. Apolipoprotein A-I, an acute phase reactant (APR) that declines during systemic inflammation (reverse APR), inhibits cytokine production by interfering in the T cell-monocyte interaction. Although the effects of IL-1 and TNF-alpha overlap, they have somewhat differing roles in RA on the basis of evidence from several animal models. TNF-alpha appears to play a more important role in triggering events leading to inflammation both locally and systemically, whereas IL-1 is more involved at the local level in processes leading to cartilage and bone destruction and in impeding cartilage repair. However, IL-1 and TNF-alpha strongly synergize in numerous biological functions, both in vitro and in vivo. Blockade of IL-1 and TNF-alpha simultaneously provides favorable effects in collagen and adjuvant induced arthritis, illustrating the importance of both cytokines.
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PMID:Interleukin 1 or tumor necrosis factor-alpha: which is the real target in rheumatoid arthritis? 1223 16

In 1996 a new murine model of spontaneous arthritis was described by the group of Benoist and Mathis. Mice transgenic for a T cell receptor recognizing an epitope of bovine RNase and bred onto a NOD background developed severe destructive arthritis, which resembles human rheumatoid arthritis in many respects. The development of disease requires the presence of T and B lymphocytes and is dependent on the MHC class II molecule I-A(g7). B cell activation by antigen and an additional CD40-CD40 ligand interaction was found to give rise to the production of autoantibodies. Glucose-6-phosphate isomerase was identified as the target of the autoantibodies; moreover, the transgenic T cells were demonstrated to exhibit a dual specificity for both bovine RNase and glucose-6-phosphate isomerase. Importantly, the arthritis is serum transferable to normal recipients, enabling the examination of the pathogenic mechanisms of joint inflammation and destruction. Recent studies suggest the crucial involvement of the innate immune system in the development of antibody-induced arthritis. Complement components, Fc receptors and neutrophils are indispensable for disease induction. An overview of the existing data is given and the emerging concepts of the pathogenesis of the K/BxN arthritis are discussed with respect to their relevance for human rheumatoid arthritis. Because of the reliable and robust induction of joint inflammation by serum transfer this new disease model has been and will be a valuable means to address the as-yet-unanswered key questions related to the development of arthritis.
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PMID:The KRN mouse model of inflammatory arthritis. 1290 93

Dendritic cells (DCs) retrovirally transduced with IL-4 have recently been shown to inhibit murine collagen-induced arthritis and associated Th1 immune responses in vivo, but the mechanisms that underly these effects are not yet understood. In this report we demonstrate that IL-4-transduced DCs loaded with antigen led to lower T cell production of IFN-gamma, increased production of IL-4, and an attenuated, delayed type hypersensitivity response. We hypothesized that the ability of such DCs to regulate the Th1 immune response in vivo depends in part on their capacity to produce IL-12 and IL-23. Quantitative mRNA analysis revealed that IL-4-transduced DCs stimulated with CD40 ligand expressed higher levels of IL-12p35 mRNA, but lower levels of mRNA for IL-23p19 and the common subunit p40 found in both IL-12 and IL-23, compared with control DCs. These results, which indicate that expression of the IL-12 and IL-23 subunits is differentially regulated in IL-4-transduced DCs, were confirmed by ELISA of the IL-12 and IL-23 heterodimers. Thus, therapeutic suppression of Th1 -mediated autoimmunity (as recently shown in murine collagen-induced arthritis) and induction of Th2 responses in vivo by IL-4-transduced DCs occurs despite their potential to produce increased levels of IL-12, but could reflect, in part, decreased production of IL-23.
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PMID:Cytokine production by dendritic cells genetically engineered to express IL-4: induction of Th2 responses and differential regulation of IL-12 and IL-23 synthesis. 1571 52

Multiple mechanisms of tolerance are induced by oral antigen. Low doses favor active suppression, whereas higher doses favor clonal anergy/deletion. Oral antigen induces T-helper 2 [interleukin (IL)-4/IL-10] and Th3 [transforming growth factor (TGF)-beta] T cells plus CD4+CD25+ regulatory cells and latency-associated peptide+ T cells. Induction of oral tolerance is enhanced by IL-4, IL-10, anti-IL-12, TGF-beta, cholera toxin B subunit, Flt-3 ligand, and anti-CD40 ligand. Oral (and nasal) antigen administration suppresses animal models of autoimmune diseases including experimental autoimmune encephalitis, uveitis, thyroiditis, myasthenia, arthritis, and diabetes in the non-obese diabetic (NOD) mouse, plus non-autoimmune diseases such as asthma, atherosclerosis, graft rejection, allergy, colitis, stroke, and models of Alzheimer's disease. Oral tolerance has been tested in human autoimmune diseases including multiple sclerosis (MS), arthritis, uveitis, and diabetes and in allergy, contact sensitivity to dinitrochlorobenzene (DNCB), and nickel allergy. Although positive results have been observed in phase II trials, no effect was observed in phase III trials of CII in rheumatoid arthritis or oral myelin and glatiramer acetate (GA) in MS. Large placebo effects were observed, and new trials of oral GA are underway. Oral insulin has recently been shown to delay onset of diabetes in at-risk populations, and confirmatory trials of oral insulin are being planned. Mucosal tolerance is an attractive approach for treatment of autoimmune and inflammatory diseases because of lack of toxicity, ease of administration over time, and antigen-specific mechanisms of action. The successful application of oral tolerance for the treatment of human diseases will depend on dose, developing immune markers to assess immunologic effects, route (nasal versus oral), formulation, mucosal adjuvants, combination therapy, and early therapy.
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PMID:Oral tolerance. 1604 53


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