Autoantigen

Structures expressed in the organs of an individual against his own immune system can mount an immune response. Autoantigens can be organ specific (e.g. insulin) or present in all cells (e.g. DNA). 

It is clear that generated by such a random process the initial repertoire of antigen specifity in all individuals of human beings should be quite similar. This implies that initially in each individal there develop lymphocytes which recognize antigens of this very individual, i.e. autoantigens. 

T- or B-lymphocytes which react with autoantigens. In healthy individuals kept under control by the mechanisms of self tolerance. 

It is an autoantibody whose autoantigen is the Fc portion of IgG. Rheumatoid factors may be of any immunoglobulin isotype but it is IgM rheumatoid factor that is commonly measured in rheumatoid arthritis. Classification criteria for rheumatoid arthritis include only one serological test, namely rheumatoid factor. However, it is not diagnostic test rather it may be confirmatory when a number of other clinical features are present. 

During differentiation of T- or B-lymphocytes antigen recqrtors are generated which react to self or autoantigens. These are generally eliminated by the mechanisms of central tolerance or kept silent by the mechanisms of peripheral tolerance ( autoimmune disease). 

Natter S. Seiberler S, Hufnagl P, Binder BR, Hirschl AM. Ring J, Abeck D. Schmidt T, Valent P, Valenta R Isolation of cDNA clones coding for IgE autoantigens with serum IgE from atopic dermatitis patients. FASEB J 1998 12 1559-1569. 

In various types of arthritis, proteoglycans may act as autoantigens, thus contributing to the pathologic feamres of these conditions. The amount of chondroitin sulfate in cartilage diminishes with age, whereas the amounts of keratan sulfate and hyaluronic acid increase. These changes may contribute to the development of osteoarthritis. Changes in the amounts of cer-... 

Oppenheim JJ, Dong HF, Plotz P, et al. Autoantigens act as tissue-specific chemoattractants. J Leukoc Biol 2005 77(6) 854-861. 

Verheijden GF, Rijnders AW, Bos E et al 1997 Human cartilage glycoprotein-39 as a candidate autoantigen in rheumatoid arthritis. Arthritis Rheum 40 1115—1125... 

Eystathioy, T., Chan, E. K., Tenenbaum, S. A., Keene, J. D., Griffith, K., and Fritzler, M. J. (2002). A phosphorylated cytoplasmic autoantigen, GW182, associates with a unique population of human mRNAs within novel cytoplasmic speckles. Mol. Biol. Cell 13,... 

Holcik, M., and Korneluk, R. G. (2000). Functional characterization of the X-linked inhibitor of apoptosis (XIAP) internal ribosome entry site element Role of La autoantigen in XIAP translation. Mol. Cell Biol. 20, 4648-4657. 

Many environmental factors have been implicated in the induction of autoimmunity. One dietary component, iodine, has been well studied as a factor that increases autoimmune thyroid disease.67 68 Based on studies in the OS chicken, the increasing prevalence of autoimmune thyroid disease observed in U.S. and Western European populations has been ascribed to increased use of iodized salt.69 Experimentally, it can be shown that iodinated thyroglobulin is a more potent autoantigen than the equivalent noniodinated molecule. Food additives or pesticides may also be important in contributing to the development of autoimmune disease in susceptible individuals.70... 

Hall, J.C., Casciola-Rosen, L., and Rosen, A., Altered structure of autoantigens during apoptosis,. Rheum. Dis. Clin. North Am., 30, 455, 2004. 

Eliasson, E. and Kenna, J.G., Cytochrome P450 2E1 is a cell surface autoantigen in halo-thane hepatitis, Mol. Pharmacol., 50, 573, 1996. 

Leeder, J.S., Lu, X., Timsit, Y., and Gaedigk, A., Non-monooxygenase cytochromes P450 as potential human autoantigens in anticonvulsant hypersensitivity reactions, Pharmacogenetics, 8, 211, 1998. 

Bourdi, M. et al., Human cytochrome P450 2E1 is a major autoantigen associated with halothane hepatitis, Chem. Res. Toxicol., 9, 1159, 1996. 

Genetically predisposed animals or induced animal models may also be used to study and predict chemical-induced autoimmunity. In induced models, a susceptible animal strain is immunized with a mixture of an adjuvant and an autoantigen isolated from the target organ. Examples are adjuvant arthritis (AA), experimental allergic encephalomyelitis (EAE) and experimental uveitis in the Lewis strain rat. Examples of spontaneous models... 

Similar searches detect VWA domains in the DNA-binding Ku70 and Ku80 proteins that are subunits of a heterodimeric autoantigen of ap-... 

Neugebauer K.M., Merrill J.T., Wener M.H., Lahita R.G., and Roth M.B. (2000), SR proteins are autoantigens in patients with systemic lupus erythematosus. Importance of phosphoepitopes, Arthritis Rheum. 43, 1768-1778. 

Zhou Z. and Menard H.A. (2002), Autoantigenic posttranslational modifications of proteins does it apply to rheumatoid arthritis , Curr. Opin. Rheumatol. 14,250-253. 

Tarbell KV, Yamazaki S, Olson K, Toy P, Steinman RM CD25+CD4+ T cells, expanded with dendritic cells presenting a single autoantigenic peptide, suppress autoimmune diabetes. J Exp Med 2004 199 1467-1477. 

---