Listeria monocytogenes is a food-borne, grampositive bacterium that causes infections (listeriosis) in individuals with compromised immune systems. Listeria is predominantly an intracellular pathogen....

Listeria monocytogenes is a food-borne, grampositive bacterium that causes infections (listeriosis) in individuals with compromised immune systems. Listeria is predominantly an intracellular pathogen. After phagocytosis by intestinal macrophages, Listeria escapes the phagosome and replicates in the cytosol before spreading to other neighboring cells through a special invasion process that allows it to remain intracellular while spreading from cell to cell.

A. What advantage is there for Listeria to invade and spread intracellular?

B. What immune response is primarily responsible for controlling Listeria infection in healthy but unimmunized individuals?

C. What immune response is primarily responsible for controlling Listeria infection in healthy individuals who have had prior exposure to Listeria?

D. How are Listeria antigens presented to immune cells?