Researchers at the National Institutes of Health have discovered a therapy that targets host cells rather than bacterial cells in treating bacterial pneumonia. The method involves white blood cells of the immune system called macrophages that eat bacteria, and a group of compounds that are naturally produced in mice and humans called epoxyeicosatrienoic acids or EETs. Even though EETs’ normal function is to limit inflammation during infections caused by S. pneumoniae and other microorganisms, inflammation ramps up after these lung cells induce certain substances that prompt macrophages to eat the bacteria. So, scientists say that one way to get macrophages to eat more bacteria is to decrease the ability of EETs to do what they normally do, which is limit inflammation. The research, published in Journal of Clinical Investigation, says this will help to find a way to augment the body’s immune system to resolve the infection. 

According to the World Health Organization, pneumonia caused by Streptococcus pneumoniae, or pneumococcal pneumonia, is the leading cause of pneumonia deaths worldwide each year. While physicians usually prescribe antibiotics to treat this severe lung infection, treatment is not always successful, and in some cases, the bacteria become resistant.