Expression Dynamics of Human Cytomegalovirus Immune Evasion Genes US3, US6, and US11 in the Blood of Lung Transplant Recipients

Delayed elimination of human cytomegalovirus (HCMV)-infected cells by the host immune system may contribute to viral dissemination and pathogenesis of HCMV infection. The mRNA expression dynamics of HCMV-encoded immune evasion genes US3, US6, and US11 expressed after active HCMV infection were analyzed in blood samples of lung transplant recipients by means of quantitative nucleic acid sequence-based amplification. The results were compared with the expression dynamics of IE1 mRNA and pp67 late mRNA, levels of pp65 antigenemia, and antiviral treatment. During acute infection, high levels of US3 and US6 RNA were detected before antigenemia, which were detected simultaneously with IE1 RNA. US11 RNA was detected simultaneously with antigenemia but before late pp67 RNA. These data suggest an active role of viral immune evasion during HCMV infection in vivo. Interestingly, immune evasion RNA remained detectable after clinical recovery, often independently of IE1 RNA expression, indicating persistent viral activity, which may have implications for long-term control of HCMV.