Human cytomegalovirus (HHV5) reactivation during lactation

Area of Science:

• Virology
• Immunology
• Neonatal Health

Background:

• Human cytomegalovirus (HCMV) is a widespread virus causing lifelong latent infections.
• Reactivation can lead to severe disease in immunocompromised individuals and poses risks via breast milk transmission, particularly for preterm infants.
• HCMV employs sophisticated mechanisms to maintain latency and evade host immune responses.

Purpose of the Study:

• To review the molecular biology and pathogenesis of HCMV.
• To emphasize the interplay between viral and host factors in HCMV latency and reactivation.
• To highlight the significance of milk-mediated HCMV transmission in neonatal health.

Main Methods:

• This review synthesizes current knowledge from existing literature.
• It focuses on molecular mechanisms regulating HCMV latency and reactivation.
• The review examines viral strategies for immune evasion and host-pathogen interactions.

Main Results:

• HCMV latency is maintained by viral proteins and miRNAs that suppress gene expression.
• Viral factors like LUNA, UL138, and US28 are crucial for latency.
• HCMV evades immune detection by downregulating MHC class II presentation and producing IL-10 homologs.
• Reactivation is triggered by cellular differentiation or inflammatory cytokines, leading to viral replication.

Conclusions:

• Understanding HCMV latency and reactivation is critical for managing infections.
• Milk-mediated transmission is a significant concern for neonatal health, necessitating risk mitigation strategies like breast milk pasteurization.
• Further research into viral and host factors is essential for developing effective interventions against HCMV.