The phosphoenolpyruvate phosphotransferase system (PTS) is a phosphotransfer cascade that regulates bacterial metabolism, behavior, and the transport of many sugars. Glucose-specific enzyme IIA (EllAGlc) is component of the PTS that carries out phosphotransfer and regulates both membrane-associated and cytoplasmic partners through direct protein-protein interactions. Here Vijayakumar et al identify an amphipathic helix at the N-terminus of Vibrio cholerae EIIAGlc that enables this protein to associate with the inner membrane. This amphipathic helix is essential for EIIAGlc regulation of membrane-associated partners, and Dr. Vijayakumar shows that unrelated amphipathic helices can rescue function. Removal of this amphipathic helix uncouples phosphotransfer through the PTS from sugar transport. Finally, Dr. Vijayakumar shows that EIIAGlc regulates opposing cytoplasmic and membrane-associated regulators of biofilm formation and bacterial metabolism in the mammalian intestine whose activities may be studied in isolation by removal of the amphipathic helix.
In this publication, we show that our sublingual vaccine platform can be engineered to constitutively synthesize the attenuated cholera toxin-based adjuvant mmCT in situ leading to boosting of the mucosal immune response.
Here Liao and colleagues describe an antigen presentation platform based on fusion of antigens to the Vibrio cholerae biofilm matrix protein RbmA with delivery in the form of a whole cell, live-attenuated vaccine. We show that fusion of the B subunit of cholera toxin (CTB) to RbmA and presentation via sublingual delivery of whole cells results in a mucosal immune response to both the V. cholerae O-antigen and CTB.