Study in a Sentence: Researchers have produced a human-based stem cell model of the brain that supports the entry of SARS-CoV-2 and serves as an model for studying central nervous system (CNS) symptoms of COVID-19.
Healthy for Humans: Evidence suggests that SARS-CoV-2 can infect the human central nervous system, leading to the inflammation of blood vessels and followed by conditions like clotting, seizures, strokes, and hemorrhages. Brain organoids are a powerful tool for understanding mechanisms and developing treatments for diseases affecting the brain, but previous brain organoids containing human neural cells could not be infected with SARS-CoV-2, hampering this important research.
Redefining Research: Here, researchers introduced to their brain organoids an additional cell type: pericytes, a specialized cell that wraps around blood vessels and regulates immune cell entry to the CNS. The resulting novel ‘assembloid’ model showed substantial infection by SARS-CoV-2, indicating that one possible route of the virus into the brain is through the blood vessels, where SARS-CoV-2 can infect pericytes and then spread to other types of brain cells. This model provides insight into the impact of SARS-CoV-2 on the human brain and may be useful for modeling other infectious diseases as well.