title: Engineered vaginal lactobacillus strain for mucosal delivery of the human immunodeficiency virus inhibitor cyanovirin-N.
abstract: Women are at significant risk of human immunodeficiency virus (HIV) infection, with the cervicovaginal mucosa serving as a major portal for virus entry. Female-initiated preventatives, including topical microbicides, are urgently needed to help curtail the HIV/AIDS pandemic. Here we report on the development of a novel, live microbicide that employs a natural vaginal strain of Lactobacillus jensenii engineered to deliver the potent HIV inhibitor cyanovirin-N (CV-N). To facilitate efficient expression of CV-N by this bacterium, the L. jensenii 1153 genome was sequenced, allowing identification of native regulatory elements and sites for the chromosomal integration of heterologous genes. A CV-N expression cassette was optimized and shown to produce high levels of structurally intact CV-N when expressed in L. jensenii. Lactobacillus-derived CV-N was capable of inhibiting CCR5-tropic HIV(BaL) infectivity in vitro with a 50% inhibitory concentration of 0.3 nM. The CV-N expression cassette was stably integrated as a single copy into the bacterial chromosome and resolved from extraneous plasmid DNA without adversely affecting the bacterial phenotype. This bacterial strain was capable of colonizing the vagina and producing full-length CV-N when administered intravaginally to mice during estrus phase. The CV-N-producing Lactobacillus was genetically stable when propagated in vitro and in vivo. This work represents a major step towards the development of an inexpensive yet durable protein-based microbicide to block the heterosexual transmission of HIV in women.
authors.affiliation: Osel, Inc, Santa Clara, CA 95054, USA.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Liu
authors.forename: Laurel A
authors.initials: LA
authors.lastname: Lagenaur
authors.forename: David A
authors.initials: DA
authors.lastname: Simpson
authors.forename: Kirsten P
authors.initials: KP
authors.lastname: Essenmacher
authors.forename: Courtney L
authors.initials: CL
authors.lastname: Frazier-Parker
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Daniel
authors.initials: D
authors.lastname: Tsai
authors.forename: Srinivas S
authors.initials: SS
authors.lastname: Rao
authors.forename: Dean H
authors.initials: DH
authors.lastname: Hamer
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Parks
authors.forename: Peter P
authors.initials: PP
authors.lastname: Lee
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xu
mesh_terms: D000282:Administration, Intravaginal; D000818:Animals; D019380:Anti-HIV Agents / Q000378:metabolism / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D005818:Genetic Engineering / Q000379:methods*; D015658:HIV Infections / Q000517:prevention & control / Q000635:transmission; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D007778:Lactobacillus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D008254:Macaca nemestrina; D008969:Molecular Sequence Data; D009092:Mucous Membrane / Q000382:microbiology; D014621:Vagina / Q000382:microbiology*
chemical_list: D019380:Anti-HIV Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; C107733:cyanovirin N