The pathogenic Neisseriae, Neisseria meningitidis and Neisseria gonorrhoeae, initiate colonization of host epithelial cells using type IV pili. N. gonorrhoeae type IV pili are retractile structures essential for DNA transformation and motility in addition to epithelial cell attachment. Pilus retraction generates a significant force (100 pN) on the substrate to which it is attached. Retraction of pili by N. gonorrhoeae has been shown to activate stress-related signaling cascades, including the PI3K/Akt kinase pathway. A functional p/VTis required for pilus retraction as well as complete activation of the PI3K/Akt pathway, strongly indicating that this cascade is activated by pilus retraction. Upon activation, PI3K produces PI (3, 4, 5) P3, a lipid second messenger that influences bacterial behavior. These observations lead to the hypothesis that N. gonorrhoeae engages in a dialogue with the epithelial cell during the attachment phase of infection. The goals of this application are to evaluate the effect offered on activation of the PI3K/Akt pathway and to establish whether PI (3, 4, 5) P3 acts as a signal to N. gonorrhoeae. ? ?