Human Cytomegalovirus Escape from Immune Detection

Human cytomegalovirus (CMV) has devised numerous means of escaping immune surveillance. The CMV genome encodes at least 4 genes involved in downregulating surface expression of HLA class I molecules. In addition, it sequesters CC chemokines, induces Fc receptors, interferes with induction of HLA class II antigens, and can inhibit natural killer cell activity. CMV can efficiently block the presentation of immediate early antigens, the first viral proteins to be produced. Together, these mechanisms probably contribute to the ability of CMV to persist in its host and may play a role in the immunopathology of CMV disease.