INHIBITION OF MHC CLASS-I ANTIGEN PRESENTATION BY VIRAL-PROTEINS

An essential part of the immune response to viral infections is the re cognition and elimination of infected cells by cytotoxic T lymphocytes . For this purpose a display mechanism has evolved which is present in almost all nucleated cells: the major histocompatibility complex clas s I antigen processing pathway. Both self and foreign antigens are deg raded in the cytosol to peptides which are translocated into the endop lasmic reticulum where they are loaded onto MHC class I molecules. Pat hogens living inside the cell are evolving under the constant selectio n pressure of such immune surveillance. As a result such infectious or ganisms have developed a variety of strategies to prevent their antige ns from being presented. Since our understanding of the cell biology o f antigen presentation has greatly advanced in recent years, it has no w become possible to unravel several of the molecular mechanisms by wh ich viruses interfere with MHC class I antigen presentation. Examples for the interference of viral molecules with components of the MHC cla ss I pathway are presented in this review.