Why should cell biologists study microbial pathogens?

Welch, Matthew D.

To influence host cells, each pathogen produces a distinct set of virulence factors that target specific host cell structures, pathways, and molecules. The function of virulence factors differs depending on where the pathogen establishes residence (Figure 1 ). Extracellular pathogens reside around or in contact with host cells but resist internalization into cells. They produce virulence factors that inhibit phagocytosis and otherwise disable elements of the immune response. Intracellular pathogens instead encourage their internalization into host cells, grow within a preferred cellular compartment or organelle, and then exit the cell to disseminate the infection. They produce virulence factors that promote phagocytosis, enable movement to their preferred compartment, manipulate membrane trafficking and autophagy to resist killing and permit growth and replication, and exit the cell to promote spread.