Michael Betts and his lab have focused on recoverable viruses like influenza and those that never leave human bodies like HIV. He explains different mechanisms of responses as well as what’s been unusual about our immune system and COVID-19.
Michael Betts is a professor of microbiology at the Penn Institute for Immunology. His lab studies human-specific responses to viruses. He begins by explaining the immune system in general from a microbiologist perspective. He comments that our initial response to most viruses of lethargy and fever is pretty similar. This is an active phase to eliminate the virus if possible.
He adds that with viruses like HIV, your body is not able to eliminate the virus. He explains in what ways the virus replication is always a step ahead and how its high replication rate is an advantage for the virus. He provides other examples, like the ability of CMV to encode an MHC complex decoy to evade detection by the CD8+ T cells.
He also describes what the field of immunology has observed with COVID-19 and describes his lab work specifically. He says that the initial response is not different from other infections, but the continuing outcomes and manifestations of those outcomes run the gamut. They’ve focused on reactions of T-cells and the innate immune system, which is mediated by several types of cells like monocytes.
They are noticing that severe COVID-19 has an impact on the innate lymphocyte population. They are seeing very dramatic changes in cell surface protein expression and in the population of cells called neutrophils, namely an extreme elevation of these in the blood. The cell surface protein effect is most pronounced in people with severe disease, not mild or moderate, which means it may help gauge reactions and treatments.