The neonatal Fc receptor (FcRn): Guardian or Trojan Horse in viral infection?

Area of Science:

• Immunology
• Virology
• Molecular Biology

Background:

• The neonatal Fc receptor (FcRn) is essential for transferring maternal immunoglobulin G (IgG) to neonates, supporting antimicrobial defenses.
• FcRn regulates IgG and albumin homeostasis, prolonging their circulation time through pH-dependent recycling.
• FcRn facilitates antibody transcytosis across cellular barriers, vital for humoral immunity.

Purpose of the Study:

• To comprehensively review the dual roles of FcRn in viral infections.
• To elucidate how various viruses exploit FcRn to promote infection.
• To summarize molecular mechanisms of FcRn-mediated proviral processes.

Main Methods:

• Literature review of studies on FcRn and viral infections.
• Analysis of molecular mechanisms of FcRn exploitation by viruses.
• Identification of therapeutic strategies targeting FcRn.

Main Results:

• FcRn plays a dual role, aiding immune defenses but also facilitating viral infections.
• Viruses utilize FcRn for processes like viral uncoating and transcytosis.
• Antibody-dependent enhancement (ADE) of infection is a key FcRn-mediated proviral mechanism.

Conclusions:

• Viruses strategically exploit FcRn's natural functions for their own replication and spread.
• Understanding these molecular mechanisms is key to developing novel antiviral therapies.
• Targeting FcRn presents a promising strategy to inhibit viral replication and enhance immune responses.