In
immunology
Immunology is a branch of biology and medicine that covers the study of Immune system, immune systems in all Organism, organisms.
Immunology charts, measures, and contextualizes the Physiology, physiological functioning of the immune system in ...
, cryptic self epitopes are a source of
autoimmunity
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 ...
.
Self epitopes, which are found in high concentration on the surface of
antigen-presenting cell
An antigen-presenting cell (APC) or accessory cell is a Cell (biology), cell that displays an antigen bound by major histocompatibility complex (MHC) proteins on its surface; this process is known as antigen presentation. T cells may recognize the ...
s (APCs) in association with its
major histocompatibility complex
The major histocompatibility complex (MHC) is a large Locus (genetics), locus on vertebrate DNA containing a set of closely linked polymorphic genes that code for Cell (biology), cell surface proteins essential for the adaptive immune system. The ...
(MHC) are known as dominant epitopes. These are stimulants of
negative selection mechanisms to remove potentially self destructing autoreactive
T cells
T cells (also known as T lymphocytes) are an important part of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their ce ...
. Their "self" antigens are displayed to a developing T-cell and signal those "self-reactive" T-cells to die via programmed cell death (
apoptosis
Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biol ...
) and thereby
deletion from the T cell repertoire, preventing autoimmunity.
However, self epitopes which appear in very low concentration on APC are termed cryptic in the sense that they do not delete autoreactive T-cells which will then join the peripheral adult T cell repertoire. This causes autoimmunity in the body.
References
*{{cite journal , pmc=2192044 , pmid=7539032 , volume=181 , issue = 6, title=How can cryptic epitopes trigger autoimmunity? , year=1995 , journal=J. Exp. Med. , pages=1945–8 , last1 = Lanzavecchia , first1 = A , doi=10.1084/jem.181.6.1945
Immunology
Autoimmune diseases