Description:

Legionella pneumophila (Lpn) is a gram-negative bacterium that infects human macrophages and causes a life-threatening form of pneumonia known as Legionnaires' Disease. Lpn possesses a Type II Secretion (T2S) system that secretes >25 different proteins. To determine the role of T2S during infection, a T2S mutant was examined at various stages throughout the mammalian infection cycle. T2S was dispensable for entry and evasion of host degradative pathways, but was shown to promote subsequent intra-vacuolar growth. Interestingly, T2S influenced the recruitment and/or retention of host proteins to the bacterial replication vacuole. T2S was especially important for growth in the absence of host GTPase activation, elaborating an under-appreciated role for T2S during Lpn infection.

Richard White

Driskill Graduate Program, Northwestern University

Laboratory of Dr. Nick Cianciotto