Are Pericytes How the Coronavirus Can Sneak Past the Blood-Brain Barrier?
July 23, 2021
Research and clinical observations have shown that the central nervous system (brain and spinal cord) is directly or indirectly affected by SARS-CoV-2 infection, though there has been no evidence of the virus infecting nerve cells themselves. In this recent study, an artificially grown mass of cells was created, mimicking a brain, and was infected with the coronavirus. The “cortical brain organoids” remained impervious to COVID-19. However, knowing that autopsy studies have shown that SAR-CoV-2 has the potential to spread throughout the brain, the researchers pressed on.
The main function of pericytes is to regulate blood flow in the brain, help maintain homeostasis within the body, and sustain the blood-brain barrier. What made these cells of particular interest to the researchers is that pericytes, unlike most neural cells, have high expressions of ACE2, the surface protein that SARS-CoV-2 uses to enter and infect cells. The researchers attempted to infect the cortical brain organoid again with the coronavirus, only this time they added pericytes, and an incredibly robust infection occurred. They found that the pericytes acted like ‘viral replication hubs’ following infection, allowing the virus to multiply and begin targeting astrocytes (immune cells crucial for several protective and regulatory functions in the brain). The researchers stated that the findings suggest that pericytes could potentially serve as an entry point for SARS-CoV-2.