Laurel Lagenaur and the team at Osel, Inc. in the U.S. will engineer a native human vaginal Lactobacillus to secrete a potent and broadly antiviral domain antibody fragment and evaluate the microbe's ability to prevent HIV infection in the vaginal mucosa. In this project's Phase I research, Lagenaur's team examined levels of expression of HIV-neutralizing proteins by Lactobacillus. Recently several broadly neutralizing domain antibodies have been identified. In Phase II, the team will focus on engineering the natural vaginal bacteria to express the higher potency antiviral antibody m36.4, and test in vivo the strain's ability to protect against (S)HIV challenge in macaques.