John MacMicking investigates how individual cells protect themselves against major pathogens. This broad-based system of non-classical host defense is called cell-autonomous immunity and operates across the three domains of life. MacMicking and his team are characterizing the antimicrobial genes and circuitry constituting the cell-autonomous defense network in mammals and their inheritance from earlier multicellular and prokaryotic systems. The team wants to know: the identity of protein machineries and signaling hubs involved in restricting intracellular pathogens; whether such pathways operate in the cytosol or on specialized organelles; and if common sets of host effectors are shared across all diploid cells, or if cell-specific defense modules evolved in diverse organs and tissues.
Scientists have found that cells that line human lungs and other tissues express a protein that can halt SARS-CoV-2 replication before the virus spreads to nearby cells. Their discovery could one day point to new therapeutic strategies to treat or prevent COVID-19, particularly for individuals who are more vulnerable to severe infection. Plants’ immune defenses falter during heat waves, rendering them more vulnerable to insects and pathogens under climate change. HHMI scientists have now figured out why high temperatures knock out a key defense system and they’ve come up with a strategy that bolsters plant immunity. Researchers have discovered that a molecule found within many of the body’s cells kills germs by dissolving their protective membranes.