Cytomegalovirus immune evasion by perturbation of endosomal trafficking

Area of Science:

• Immunology
• Virology
• Cell Biology

Background:

• Cytomegaloviruses (CMVs), part of the herpesvirus family, employ sophisticated strategies to evade host immune responses, enabling survival and latent infection.
• CMVs subvert adaptive immunity by downregulating cell surface expression of MHC Class I and Class II molecules, preventing viral antigen presentation to T lymphocytes.
• CMVs also evade innate immunity by interfering with natural killer (NK) cell recognition through modulation of activating and inhibitory ligands.

Purpose of the Study:

• To review the mechanisms by which CMVs and other herpesviruses manipulate endocytic trafficking pathways.
• To elucidate how these perturbations of endosomal systems contribute to viral immune evasion.
• To summarize the current understanding of how viral infections affect the cell surface expression of immune recognition molecules.

Main Methods:

• Review of existing literature on CMV and herpesvirus immunoevasion strategies.
• Analysis of cellular protein trafficking, focusing on endocytosis and the endosomal system.
• Examination of viral protein functions in the biosynthetic and endocytic pathways.

Main Results:

• CMVs encode proteins that inhibit the assembly and cell surface trafficking of immune recognition molecules.
• Viral manipulation of endosomal routes leads to the relocation of immune molecules from the cell surface to intracellular compartments.
• These disruptions effectively shield infected cells from both adaptive and innate immune surveillance.

Conclusions:

• Endocytic trafficking of immune recognition molecules is a critical target for CMV immune evasion.
• Herpesviruses exploit and perturb the endosomal system to prevent the display of viral antigens and evade immune detection.
• Understanding these mechanisms provides insights into viral pathogenesis and potential therapeutic targets.