Figure 4.

(A) Vi negative Salmonella activates small Rho family GTPases, Cdc42, and Rac-1, that bring about actin polymerisation & activation NF-kB and MAP-kinase pathways of intracellular signaling resulting in invasion and induction of inflammatory responses. (B) Vi present on the surface of Vi-positive Salmonella and released in the extracellular milieu (or Vi provided with Vi negative Salmonella) specifically engages membrane prohibitin that prevents activation of Cdc42 & Rac-1 resulting in reduced invasion of cells with Salmonella and inhibition of inflammatory responses.