In immunology, autoimmunity is the system of immune responses of an organism against its own healthy cells, tissues and other normal body constituents. Any disease resulting from this type of immune response is termed an "autoimmune disease". Prominent examples include celiac disease, post-infectious IBS, diabetes mellitus type 1, Henoch–Schönlein purpura (HSP) sarcoidosis, systemic lupus erythematosus (SLE), Sjögren syndrome, eosinophilic granulomatosis with polyangiitis, Hashimoto's thyroiditis, Graves' disease, idiopathic thrombocytopenic purpura, Addison's disease, rheumatoid arthritis (RA), ankylosing spondylitis, polymyositis (PM), dermatomyositis (DM), and multiple sclerosis (MS). Autoimmune diseases are very often treated with steroids.
The major histocompatibility complex (MHC) is a large locus on vertebrate DNA containing a set of closely linked polymorphic genes that code for cell surface proteins essential for the adaptive immune system. These cell surface proteins are called MHC molecules.
The human leukocyte antigen (HLA) system or complex is a complex of genes on chromosome 6 in humans which encode cell-surface proteins responsible for regulation of the immune system. The HLA system is also known as the human version of the major histocompatibility complex (MHC) found in many animals.
Ankylosing spondylitis (AS) is a type of arthritis characterized by long-term inflammation of the joints of the spine, typically where the spine joins the pelvis. Occasionally, areas affected may include other joints such as the shoulders or hips. Eye and bowel problems may occur as well as back pain. Joint mobility in the affected areas generally worsens over time.
Human leukocyte antigen (HLA) B27 is a class I surface antigen encoded by the B locus in the major histocompatibility complex (MHC) on chromosome 6 and presents antigenic peptides to T cells. HLA-B27 is strongly associated with ankylosing spondylitis and other associated inflammatory diseases, such as psoriatic arthritis, inflammatory bowel disease, and reactive arthritis.
Spondyloarthropathy or spondyloarthrosis refers to any joint disease of the vertebral column. As such, it is a class or category of diseases rather than a single, specific entity. It differs from spondylopathy, which is a disease of the vertebra itself, but many conditions involve both spondylopathy and spondyloarthropathy.
Abacavir, sold under the brand name Ziagen among others, is a medication used to treat HIV/AIDS. Similar to other nucleoside analog reverse-transcriptase inhibitors (NRTIs), abacavir is used together with other HIV medications, and is not recommended by itself. It is taken by mouth as a tablet or solution and may be used in children over the age of three months.
MHC class I molecules are one of two primary classes of major histocompatibility complex (MHC) molecules and are found on the cell surface of all nucleated cells in the bodies of vertebrates. They also occur on platelets, but not on red blood cells. Their function is to display peptide fragments of proteins from within the cell to cytotoxic T cells; this will trigger an immediate response from the immune system against a particular non-self antigen displayed with the help of an MHC class I protein. Because MHC class I molecules present peptides derived from cytosolic proteins, the pathway of MHC class I presentation is often called cytosolic or endogenous pathway.
HLA-DR is an MHC class II cell surface receptor encoded by the human leukocyte antigen complex on chromosome 6 region 6p21.31. The complex of HLA-DR and peptide, generally between 9 and 30 amino acids in length, constitutes a ligand for the T-cell receptor (TCR). HLA were originally defined as cell surface antigens that mediate graft-versus-host disease. Identification of these antigens has led to greater success and longevity in organ transplant.
HLA class II histocompatibility antigen, DR alpha chain is a protein that in humans is encoded by the HLA-DRA gene. HLA-DRA encodes the alpha subunit of HLA-DR. Unlike the alpha chains of other Human MHC class II molecules, the alpha subunit is practically invariable. However it can pair with, in any individual, the beta chain from 3 different DR beta loci, DRB1, and two of any DRB3, DRB4, or DRB5 alleles. Thus there is the potential that any given individual can form 4 different HLA-DR isoforms.
HLA-A is a group of human leukocyte antigens (HLA) that are encoded by the HLA-A locus, which is located at human chromosome 6p21.3. HLA is a major histocompatibility complex (MHC) antigen specific to humans. HLA-A is one of three major types of human MHC class I transmembrane proteins. The others are HLA-B and HLA-C. The protein is a heterodimer, and is composed of a heavy α chain and smaller β chain. The α chain is encoded by a variant HLA-A gene, and the β chain (β2-microglobulin) is an invariant β2 microglobulin molecule. The β2 microglobulin protein is encoded by the B2M gene, which is located at chromosome 15q21.1 in humans.
Transporter associated with antigen processing 1 (TAP1) is a protein that in humans is encoded by the TAP1 gene. A member of the ATP-binding cassette transporter family, it is also known as ABCB2.
HLA class II histocompatibility antigen, DRB3-1 beta chain is a protein that in humans is encoded by the HLA-DRB3 gene.
HLA class I histocompatibility antigen, alpha chain F is a protein that in humans is encoded by the HLA-F gene. It is an empty intracellular molecule that encodes a non-classical heavy chain anchored to the membrane and forming a heterodimer with a β-2 microglobulin light chain. It belongs to the HLA class I heavy chain paralogues that separate from most of the HLA heavy chains. HLA-F is localized in the endoplasmic reticulum and Golgi apparatus, and is also unique in the sense that it exhibits few polymorphisms in the human population relative to the other HLA genes; however, there have been found different isoforms from numerous transcript variants found for the HLA-F gene. Its pathways include IFN-gamma signaling and CDK-mediated phosphorylation and removal of the Saccharomycescerevisiae Cdc6 protein, which is crucial for functional DNA replication.
HLA class II histocompatibility antigen, DM beta chain is a protein that in humans is encoded by the HLA-DMB gene.
HLA class II histocompatibility antigen, DM alpha chain is a protein that in humans is encoded by the HLA-DMA gene.
Type 1 tumor necrosis factor receptor shedding aminopeptidase regulator, also known as endoplasmic reticulum aminopeptidase 1 (ARTS-1), is a protein which in humans is encoded by the ARTS-1 gene.
HLA class II histocompatibility antigen, DO alpha chain is a protein that in humans is encoded by the HLA-DOA gene.
HLA class II histocompatibility antigen, DO beta chain is a protein that in humans is encoded by the HLA-DOB gene.
HLA class II histocompatibility antigen, DX beta chain is a protein that in humans is encoded by the HLA-DQB2 gene.
