Fat stores in our cells also hold immune proteins to fight infections

New Scientist 

Tiny fatty droplets in our cells are part of the immune system and help fight off bacterial infections. Until now the droplets were thought to be among the most vulnerable parts of the cell. Lipid droplets are found in the cells of all complex organisms. They store fats and other lipids, which are essential nutrients. In humans, specialised cells called adipocytes store body fat in the form of lipid droplets. For many years, biologists thought lipid droplets were "just an inert structure, just a storage site", says Robert Parton at the University of Queensland in Australia.