New paper could hint at mechanisms contributing to viral persistence in Covid 19
It’s been known for a while that SarsCov2 can inhibit one of the antiviral mechanisms the anti viral factor interferon gamma but this paper shows how this could contribute to viral persistence (caveat in macaques).
Immunology explainer
Essentially, it looks like the virus impacts the activity of a type of white blood cell called a natural killer cell (NK cells for short). NK cells are really important in the defence against viruses. They can scan cells and look for changes on their cell surface that happen when a cells is infected by a virus. One such change is reduced expression of a receptor called MHC. When NK cells detect altered cells they can directly kill the infected cells. NK cells also make antiviral products like interferons which can help prevent other cells from getting infected as well as helping kills virus.
Back to the paper
The writers focused on two important immune cell types in this paper in the lung, macrophages and natural killer cells. They saw that lung resident macrophages in chronically infected macaques were altered. Natural killer cells made less interferon gamma in infected tissues. MHC expression on chronically virally infected macrophages was up regulated so the NK cells would find it harder to find and kill virally infected cells. All this = greater chance of viral persistence.
Will remain to be seen if repeats in human cells. V interesting.
Very interesting. I knew very little about viruses before the pandemic but have become fascinated by them and how our immune system works. But my understanding is very bitty. I wondered if you could recommend a book or books (and websites) which would give me an overview on viruses, how our bodies interact with them and a glossary of key terms in virology and immunology. I’m thinking of the sort of book a 2nd year ‘A’ level/ 1st year undergraduate could use. Thank you!