Immune: A Journey Into the Mysterious System That Keeps You Alive

by Philipp Dettmer

The coronavirus targets a specific and very important receptor called ACE2. This receptor has a few vital jobs in your body, specifically regulating your blood pressure, which means you have a lot of cells in your body that carry it and can be infected. If you guessed that the epithelial cells in your nose and lungs have plenty of this receptor, you’d be right. From the perspective of a coronavirus, your lungs are miles and miles of free real estate. But the ACE2 receptor also sits on cells in a variety of tissues and organs around your body. Your blood vessels and capillaries, your heart, your gut, and your kidneys. All of them have ACE2. As we learned before, your body’s first response to a viral infection is chemical warfare, which basically does three main things: Interferons interfere with virus reproduction and slow it down, while other cytokines cause inflammation and alert immune cells. Now, one thing that makes the coronavirus so dangerous is that it seems to be able to shut down (or strongly delay) the release of interferons, while the infected cells still release all the cytokines that cause inflammation and alert the immune system. So the virus is able to infect a lot of cells and spread quickly without being slowed down, while at the same time triggering widespread inflammation and activating immune cells that will themselves cause even more inflammation.*1