Unfortunately, if used often, antibiotics end up not being efficient anymore, because our body develops resistance to drugs, and that is why we must always look for new ones. But a surprising cellular defense strategy could inspire a new category of antibiotics.
Faced with bacterial invaders, some human cells dispense a surprising substance: soap. These cells, which are not part of the immune system, release a detergent-like protein that dissolves pieces of the bacteria’s inner membranes, killing infiltrates, according to researchers who published it today in Science.
The immune cells “Professional”, like antibodies or white blood cells, get a lot of attention, but “All cells have a certain ability to fight infections”says John MacMicking, an immunologist at Yale University.
In humans, these ordinary cellular defenses have often been overlooked, MacMicking says, even though they are part of “An ancient and primordial defense system” and could make a difference in developing treatments for new infections.
Often, non-immune cells they rely on a warning from their professional counterparts to fight infections. Upon detecting strangers, specialized immune cells release an alarm signal called interferon gamma. That signal stimulates other cells, including the epithelial cells that line the throat and intestines and are often targeted by pathogens, to take action.
MacMicking and colleagues sought the molecular basis for this action by infecting laboratory versions of human skin cells with Salmonella bacteria, which can exploit the nutrient-rich interior of the cells. Then, the team examined over 19,000 human genes, looking for those that had gained some protection from infection.