Describe in/detail the/exogenous and/endogenous antigen by/apcs to/t cell
Answers
Answer:
The frog has three respiratory surfaces on its body that it uses to exchange gas with the surroundings: the skin, in the lungs and on the lining of the mouth. ... A frog may also breathe much like a human, by taking air in through their nostrils and down into their lungs.
Answer:
Antigen processing or cytosolic' pathway is an immunological process that prepares antigens for presentation to special cells of the immune system called T lymphocytes. It is considered to be a stage of antigen presentation pathways. This process involves two distinct pathways for processing of antigens from an organism's own (self) proteins or intracellular pathogens (e.g. viruses), or from phagocytosed pathogens (e.g. bacteria); subsequent presentation of these antigens on class I or class II major histocompatibility complex (MHC) molecules is dependent on which pathway is used. Both MHC class I and II are required to bind antigen before they are stably expressed on a cell surface. MHC I antigen presentation typically (considering cross-presentation) involves the endogenous pathway of antigen processing, and MHC II antigen presentation involves the exogenous pathway of antigen processing. Cross-presentation involves parts of the exogenous and the endogenous pathways but ultimately involves the latter portion of the endogenous pathway (e.g. proteolysis of antigens for binding to MHC I molecules).