What is molecular mimicry examples?
Molecular mimicry has long been implicated as a mechanism by which microbes can induce autoimmunity. 115. The best known example is rheumatic fever, in which antigenic cross-reactivity between cardiac tissue and streptococcal polysaccharides is believed to induce an autoimmune reaction targeted at the heart valves.
What are possible molecular mechanisms of autoimmunity?
Ways in which self-proteins can be altered include mutations and altered expression, posttranslational modification, covalent modifications, denaturation, native disorder or misfolding.
What is epitope spreading in autoimmune disease?
The diversification of the immune response induced by an antigen to new T cell and/or antibody specificities during the course of an autoimmune disease is known as “epitope spreading”.
What is the mechanism behind autoimmune diseases?
The fundamental underlying mechanism of autoimmunity is defective elimination and/or control of self-reactive lymphocytes. Studies in humans and experimental animal models are revealing the genetic and environmental factors that contribute to autoimmunity.
What is molecular mimicry in GBS?
GBS is considered an autoimmune disease, with the immune system mistakenly attacking myelin or axons, the nerve conduits for signals to and from the brain (32). This “mistaken immune attack” may arise because the surface of C.
Is rheumatic fever molecular mimicry?
Molecular mimicry is a hallmark of the pathogenesis of rheumatic fever where the streptococcal group A carbohydrate epitope, N-acetyl glucosamine, and the a-helical coiled-coil streptococcal M protein structurally mimic cardiac myosin in the human disease, rheumatic carditis, and in animal models immunized with …
What are the two classifications of autoimmune diseases?
Autoimmune diseases are divided into two classes: organ-specific and systemic. An organ-specific disease is one in which an immune response is directed toward antigens in a single organ.
What causes autoimmune diseases NCBI?
Autoimmune disease occurs when the immune system attacks self-molecules as a result of a breakdown of immunologic tolerance to autoreactive immune cells. Many autoimmune disorders have been strongly associated with genetic, infectious, and/or environmental predisposing factors.
What is a cryptic antigen?
A cryptic epitope is defined as a hidden or sequestered epitope that is processed and presented more efficiently as a result of an inflammatory immune response initiated by either a dominant epitope, as in a response to an infectious agent, or revealed as a result of the diversification of the response secondary to …
What is epitope Paratope?
More specifically, a paratope was defined as the set of interacting amino acid residues within a particular FR or CDR region of an antibody. An epitope is defined as the set of antigen amino acid residues that interact with a paratope.
What is the mechanism of tissue damage in autoimmune diseases?
Autoimmune diseases can be mediated by autoantibodies and/or by auto-reactive T cells, and tissue damage can result from direct attack on the cells bearing the antigen, from immune-complex formation, or from local inflammation.
What causes molecular mimicry?
Molecular mimicry is one of the leading mechanisms by which infectious or chemical agents may induce autoimmunity. It occurs when similarities between foreign and self-peptides favor an activation of autoreactive T or B cells by a foreign-derived antigen in a susceptible individual.