Modulation of Monocyte Effector Functions and Gene Expression by Human Cytomegalovirus Infection

Human cytomegalovirus (CMV) infection has significant impact on monocyte effector functions and gene expression. CMV, a β-herpesvirus, disrupts key monocyte roles, including phagocytosis, antigen presentation, cytokine production, and migration. Monocytes, crucial players in innate immunity, exhibit altered functionality upon CMV infection, impairing their ability to combat pathogens and activate adaptive immune responses. CMV modulates monocyte gene expression, decreasing their capacity for antigen presentation and phagocytosis, while increasing pro-inflammatory cytokine production, which can contribute to tissue damage and chronic inflammation. We highlight that CMV alters monocyte migration to infection sites while promoting trans-endothelial migration, thus aiding viral dissemination. Additionally, the virus affects reactive oxygen species (ROS) production, enhancing viral persistence during acute infection and facilitating immune evasion during latency. These findings underscore the clinical significance of these disruptions, particularly in immunocompromised patients such as transplant recipients, where modulation of monocyte function by CMV exacerbates risks for infection, inflammation, and graft rejection. Understanding of these mechanisms will inform therapeutic strategies to mitigate CMV-related complications in vulnerable populations.