The effect of viruses on the ability to present antigens via the major histocompatibility complex

We describe viral pathogens that cause significant human disease by their ability to interfere with the expression of major histocompatibility complex class I and II molecules. Herpesviruses and papillomaviruses encode gene products that interfere with the class I pathway of antigen processing and/or peptide translocation. Adenoviruses encode unique gene products that interfere with transport of class I molecules. Influenza virus, measles virus, and HIV interfere with the class II pathway by either suppressing the production of class II molecules or impeding antigen trafficking. Cytomegalovirus interferes with both class I and class II pathways. Better understanding of these mechanisms may lead to further insight into the pathogenesis of viral infections and allow for improved treatments.