Abstract

T lymphocytes recognize peptide antigens presented by class I and class II molecules encoded by the major histocompatibility complex (MHC). Classical antigen-presentation studies showed that MHC class I molecules present peptides derived from proteins synthesized within the cell, whereas MHC class II molecules present exogenous proteins captured from the environment. Emerging evidence indicates, however, that dendritic cells have a specialized capacity to process exogenous antigens into the MHC class I pathway. This function, known as cross-presentation, provides the immune system with an important mechanism for generating immunity to viruses and tolerance to self.

Author affiliations

1. Immunology Division, The Walter and Eliza Hall Institute, P.O. Royal Melbourne Hospital, Parkville, Victoria 3050, Australia.
2. Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3052, Australia.

Correspondence to: William R. Heath¹ Email: heath@wehi.edu.au