Research Fellows Directory
Dr Xin Li
Imperial College London
Salmonella species are important bacterial pathogens causing a variety of human diseases, such as gastroenteritis and typhoid fever. They can invade and grow inside the cells of its host, including specialised white blood cells (macrophages) whose function is to destroy potential pathogens. After entry of host cells, Salmonella resides within a membranous sac (called the Salmonella-containing vacuole or SCV), and transfers through it a large number of virulence proteins (also called effectors). We know that several of these effectors enable bacterial growth inside the vacuole by detoxifying host defences, acquiring nutrients and modifying membrane transport inside the host cells. However their specific biochemical functions are still not completely understood.
My current research is focused on understanding the dynamics and trafficking of the SCV in infected mammalian cells. To do this I am concentrating on functional analysis of two specific effectors that are translocated by Salmonella into host cells. A key objective is to identify the cellular 'targets' with which they must interact to interfere with the host. I have obtained preliminary evidence for the involvement of a family of host proteins, which function as molecular switches to regulate membrane transport, in interactions with these Salmonella effectors. Further verification of these interactions and investigation of their physiological significance is ongoing.