Geometry, Cholesterol and Kala-azar

Much of biological motion inside cells is driven by nanoscale "Motor" proteins. We have measured the pico-Newton forces exerted by Motors to carry bacteria towards acidic compartments where the bacteria is killed before it infects you. We find that Motors use an unexpected mechanism to guide these bacteria to their death.
 
Bacteria are first eaten up by cells and enclosed in a "phagosome". Small cholesterol-rich domains now appear on the membrane covering a phagosome. Many motors cluster tightly into these domains, forming a team that carries the bacteria to its death. Therefore, cholesterol, that much-hated molecule, may keep you safe from infections. I will demonstrate the relevance of our work to immune evasion of Leishmania, a deadly parasite that causes Kala-azar.