Engineered vaginal lactobacillus strain for mucosal delivery of the human immunodeficiency virus inhibitor cyanovirin-N.
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.
Liu
Xiaowen
X
Osel, Inc, Santa Clara, CA 95054, USA.
Lagenaur
Laurel A
LA
Simpson
David A
DA
Essenmacher
Kirsten P
KP
Frazier-Parker
Courtney L
CL
Liu
Yang
Y
Tsai
Daniel
D
Rao
Srinivas S
SS
Hamer
Dean H
DH
Parks
Thomas P
TP
Lee
Peter P
PP
Xu
Qiang
Q
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*
D019380:Anti-HIV Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; C107733:cyanovirin N