Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0014118 (endocarditis)
 15,629 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The immune mechanisms that provoke concomitant inflammation of synovial joints and cardiac valves in disorders such as rheumatic fever and systemic lupus erythematosus remain poorly defined. Here, we report the discovery of spontaneous endocarditis-in addition to their well-studied autoimmune arthritis-in K/BxN T cell receptor (TCR) transgenic mice. The same adaptive immune system elements were required for initiation of arthritis and endocarditis, and both diseases were dependent on autoantibodies. In contrast, the participation of key innate immune system molecules and perhaps T cells as effectors of inflammation differed between the 2 target tissues. Arthritis in K/BxN TCR transgenic mice depended primarily on complement C5 and not FcRgamma-using receptors; conversely, endocarditis depended essentially on FcRgamma receptors and not C5. Elucidating how a single systemic autoimmune disease engages distinct immune effector pathways to damage different target tissues is essential for optimizing the treatment of such disorders.
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PMID:The same systemic autoimmune disease provokes arthritis and endocarditis via distinct mechanisms. 1980 69

Toxic shock syndrome toxin-1 (TSST-1) is a potent superantigen produced by Staphylococcus aureus. In addition to menstrual and nonmenstrual toxic shock syndromes, TSST-1 is also implicated in the immunopathogenesis of pneumonia, infective endocarditis, neonatal exanthematous disease, and atopic dermatitis among others. Superantigens first bind to major histocompatibility complex (MHC) class II molecules and then activate a large proportion of T cells by cross-linking their T cell receptor. As binding to MHC class II molecules is a critical step in the robust activation of the immune system by TSST-1 and other superantigens, polymorphic variations between different HLA-DR alleles could potentially influence the magnitude of immune activation and immunopathology caused by TSST-1. As TSST-1 is highly toxic to humans and given that multiple variations of alleles of HLA-DR and HLA-DQ are expressed in each individual, it is difficult to determine how HLA-DR polymorphisms quantitatively and qualitatively impact immune activation caused by TSST-1 in humans. However, such investigations can be conducted on transgenic mice lacking all endogenous MHC class II molecules and expressing specific HLA class II alleles. Therefore, transgenic mice expressing different HLA-DRB1 alleles (HLA-DRB1*15:01, HLA-DRB1*15:02, HLA-DRB1*03:01, HLA-DRB1*04:01), and sharing HLA-A1*01:01 chain, were systemically challenged with purified TSST-1 and multiple immune parameters were assessed. Among the HLA-DR alleles, mice expressing HLA-DRB1*15:01 allele elicited a significantly higher serum cytokine/chemokine response; greater splenic T cell expansion and most severe organ pathology. Our study highlights the potential utility of human leukocyte antigen (HLA) transgenic mice in understanding the impact of HLA polymorphisms on the outcomes of diseases caused by TSST-1 and other superantigens.
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PMID:HLA-DR polymorphisms influence in vivo responses to staphylococcal toxic shock syndrome toxin-1 in a transgenic mouse model. 2786 61