Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027121 (myositis)
 4,538 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Borrelia burgdorferi induces spirochetemia, arthritis, carditis and myositis in SCID mice but not in immunocompetent co-isogenic C.B-17 mice. The contribution of naive or presensitized B and T cells in the control of spirochetal infection has now been analysed in SCID mice reconstituted with unselected spleen cells or enriched B or T cell populations thereof and subsequently challenged with B. burgdorferi. It is shown that SCID mice were protected (i) completely against disease (arthritis, carditis, myositis) by unselected spleen cells previously sensitized either to intact spirochetes or to recombinant outer surface protein A (OspA), (ii) to a large extent by mixtures of enriched spirochete-specific B and T cells, (iii) partially by equivalent preparations of presensitized B cells or by naive spleen or B cells, and (iv) not at all by presensitized or naive T cells alone. The degree of protection transferred was similar for the corresponding lymphocyte populations presensitized either to viable spirochetes or to recombinant OspA and correlated mainly with serum levels of B. burgdorferi-specific antibodies, in particular those to OspA/OspB. The capacity of enriched presensitized or naive B cells alone to generate specific antibodies of the isotypes IgM, IgG2b and IgG3, and to confer partial protection to SCID mice upon challenge with B. burgdorferi is most probably due to a B cell mitogen(s) associated with the spirochetes. These data further emphasize the important role of B cells and antibodies in the control of B. burgdorferi infection in mice, and suggest that T cells are critically involved in the optimal generation of protective antibody responses but not in the direct elimination of spirochetes from the host.
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PMID:Protection against Borrelia burgdorferi infection in SCID mice is conferred by presensitized spleen cells and partially by B but not T cells alone. 808 Aug 39

Microchimerism has been defined by the presence of a low number of circulating cells transferred from one individual to another. This transfer takes place naturally during pregnancy, between mother and fetus and/or between fetuses in multi-gestational pregnancies. Furthermore, the establishment of microchimerism can also occur during blood transfusion and organ transplants. Microchimeric cells have been implicated in health and disease. Microchimerism has been correlated with the hyporesponsiveness of the maternal immune system towards the fetal allograft and with the longevity of organ transplants. However, maternal microchimeric cells have been implicated in diseases of the neonate including neonatal graft-versus-host disease, severe combined immunodeficiency and erythema toxicum neonatorum. And more recently, microchimeric cells have been implicated in the pathogenesis of autoimmune diseases including systemic sclerosis and myositis.
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PMID:Microchimerism in health and disease. 1224 45

Anomalies of naturally occurring CD4+ regulatory T cells (Treg) cause severe autoimmune/inflammatory diseases in humans and rodents. The transcription factor Foxp3 is currently the most specific marker for natural CD4+ Treg, but it would be useful if other Treg markers, particularly cell surface molecules, could be elucidated. We demonstrate in this study that the vast majority of Foxp3-expressing CD4+ T cells (whether CD25+ or CD25-) show constitutive high-level expression of glucocorticoid-induced TNFR family-related gene/protein (GITR). Transfer of T cell or thymocyte suspensions depleted of GITR(high) cells produces in BALB/c nude mice a wider spectrum and more severe forms of autoimmune diseases than does transfer of similar cell suspensions depleted of CD25+ CD4+ T cells only. Notably, mice that receive cells depleted of GITR(high) populations develop severe multiorgan inflammation that includes fatal autoimmune myocarditis resembling giant cell myocarditis in humans, accompanying high-titer anti-myosin autoantibodies. Similar transfer of GITR(high)-depleted cells from prediabetic NOD mice to NOD-SCID mice accelerates the development of diabetes and induces skeletal muscle myositis and other autoimmune/inflammatory diseases. We conclude that GITR(high), Foxp3-expressing natural Treg, containing both CD25+ and CD25- cell populations, contribute to preventing a variety of autoimmune/inflammatory diseases, and depletion of these cells allows the activation of even weak or rare autoreactive T cells yielding widespread severe autoimmune disease. Diseases induced in this way include many which have been suspected of an autoimmune etiology in humans without much evidence. GITR(high), Foxp3-expressing natural Treg represent a potential target for the treatment and prevention of these diseases.
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PMID:Control of autoimmune myocarditis and multiorgan inflammation by glucocorticoid-induced TNF receptor family-related protein(high), Foxp3-expressing CD25+ and CD25- regulatory T cells. 1658 68

Severe combined immunodeficiency (SCID) may result from a variety of genetic defects that impair the development of T cells. Signaling mediated by the cytokine interleukin-7 is essential for the differentiation of T cells from lymphoid progenitors, and mutations of either the interleukin-7 receptor alpha chain (IL-7Ralpha) or its associated cytokine receptor chain, the common gamma chain (gammac), result in SCID. Here we report a case of SCID due to heterozygous mutations of the IL7R gene encoding IL-7Ralpha. A previously unrecognized mutation found within intron 3 created a new exon between exons 3 and 4 in the mRNA transcribed from this allele, producing a truncated, unstable mRNA. This mutation illustrates the necessity of evaluating both coding and non-coding regions of genes when searching for pathogenic mutations. Following hematopoietic stem cell transplantation of our patient, immune reconstitution was accompanied by two unusual complications, immune-mediated myositis and myasthenia gravis.
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PMID:IL-7 receptor deficient SCID with a unique intronic mutation and post-transplant autoimmunity due to chronic GVHD. 1782 65