MHC CLASS-I ANTIGEN-PROCESSING PATHWAYS

The multistep process that culminates in major histocompatibility comp lex (MHC) class I presentation of foreign or self-peptides begins in t he last phases of protein catabolism. Although the individual roles of many key molecules-such as proteasomes, the transporter associated wi th antigen processing, and various endoplasmic reticulum chaperones-ha ve recently been elucidated, there still remain many questions regardi ng processing of proteins into MHC class I bound peptides. This review summarizes the recent developments in antigen processing for MHC clas s I molecules, with a focus on how proteins are believed to be sampled and selected for degradation. (C) American Society for Histocompatibi lity and Immunogenetics, 1997.