Alveolar macrophages reside within the alveoli’s air spaces. When infected, they produce and secrete viral progeny at a leisurely pace while maintaining their normal functions. This behavior may facilitate SARS-CoV-2’s progression by incubating and generating a consistent supply of new viral particles that escape undetected and penetrate the alveoli’s enclosing cells.
Interstitial Macrophages
Interstitial macrophages patrol the alveoli’s far side, where oxygen and red blood cells meet. If an intruding viral particle or microbe manages to bypass alveolar macrophages’ surveillance, infect, and breach the alveoli’s enclosing cells, interstitial macrophages are poised to intervene and safeguard the surrounding area. However, when an interstitial macrophage encounters SARS-CoV-2, the outcome is different. Instead of being engulfed by the immune cell, the virus infects it.