Membrane ectopeptidases targeted by human coronaviruses

Area of Science:

• Virology
• Molecular Biology
• Cell Biology

Background:

• Six human coronaviruses cause respiratory illness, ranging from mild to severe.
• Viral entry into host cells requires interaction with specific cellular receptors.
• Understanding these interactions is crucial for developing antiviral strategies.

Purpose of the Study:

• To identify and characterize the host cell receptors used by human-infecting coronaviruses.
• To investigate the role of host proteases in facilitating coronavirus entry.
• To explore the implications of receptor conservation for interspecies transmission and disease severity.

Main Methods:

• Bioinformatic analysis of known coronavirus-receptor interactions.
• In vitro studies to confirm receptor binding and viral entry.
• Comparative analysis of receptor expression across different host species.

Main Results:

• Identified dipeptidyl peptidase 4 (DPP4), angiotensin-converting enzyme 2 (ACE2), and aminopeptidase N (APN) as key entry receptors for four human coronaviruses.
• Demonstrated that enzymatic activity of these receptors is not essential for viral entry.
• Showed that co-expression of host proteases enhances viral entry efficiency.
• Highlighted the evolutionary conservation of these receptors, suggesting potential for zoonotic transmission.

Conclusions:

• DPP4, ACE2, and APN are critical host factors for human coronavirus infections.
• Host proteases play a significant role in modulating viral entry and infectivity.
• The conserved nature of these receptors poses a risk for interspecies coronavirus transmission and potential pandemics.
• Dysregulation of these peptidase systems may exacerbate respiratory distress during infection.