Question

Explain the concept of cross presentation with regard to MHC

Answer 1

Cross presentation is the ability of certain antigen presenting cell to take up, process and present extracellular antigens with MHC class I molecules to cytotoxic T cells .Cross-presentation is of particular importance, because it permits the presentation of exogenous antigens, which are normally presented by MHC II on the surface of dendritic cells, to also be presented through the MHC I pathway.The MHC I pathway is normally used to present endogenous antigens that have infected a particular cell. However, cross presenting cells are able to utilize the MHC I pathway in order to remain uninfected, while still triggering an adaptive immuno response of activated cytotoxic T cells against infected peripheral tissue cells.