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One cause of antigenic escape is that a pathogen's epitopes (the binding sites for immune cells) become too similar to a person's naturally occurring MHC-1 epitopes, resulting in the immune system becoming unable to distinguish the infection from self-cells. [citation needed] Antigenic escape is not only crucial for the host's natural immune ...
There are several mechanisms that lead to escape of cancer cells to immune system, for example downregulation or loss of expression of classical MHC class I (HLA-A, HLA-B- HLA-C) [7] [4] which is essential for effective T cell-mediated immune response (appears in up to 90% of tumours [7]), development of cancer microenvironment which has ...
Many of these pathways are mediated by soluble ligands, cytokines, that fit like a lock-and-key into adjacent cell surface receptors. This language of cell communication imparts both specificity and spatiotemporal control for the transmission of data. [2] The Interferon System is composed of a family of cytokines. Type-I Interferons, IFN-α/β ...
Antigenic variation or antigenic alteration refers to the mechanism by which an infectious agent such as a protozoan, bacterium or virus alters the proteins or carbohydrates on its surface and thus avoids a host immune response, making it one of the mechanisms of antigenic escape. It is related to phase variation. Antigenic variation not only ...
The dendritic cells in the intestines cannot directly sample the antigens, as they are located behind the epithelial wall. There are different mechanisms in which the dendritic cells come in contact with the food antigens Dissolved antigens can be taken up by enterocytes. The antigens are then partially degraded in the lysosomes.
Central tolerance is essential to proper immune cell functioning because it helps ensure that mature B cells and T cells do not recognize self-antigens as foreign microbes. [2] More specifically, central tolerance is necessary because T cell receptors (TCRs) and B cell receptors (BCRs) are made by cells through random somatic rearrangement. [ 1 ]
Immunopriviledged organs evolved mechanisms in which specialized tissue cells and immune cells can mount an appropriate response without disturbing the specialized tissue. [29] Immunopathogenic disturbances are not present in a variety of specialized organs such as; the eyes, reproductive organs and the central nervous system.
Increased expression of apoptotic proteins such as BIM, or their decreased proteolysis, leads to cell death and can cause a number of pathologies, depending on the cells where excessive activity of BIM occurs. Cancer cells can escape apoptosis through mechanisms that suppress BIM expression or by increased proteolysis of BIM. [citation needed]