Inhibition of HIV Infectivity by a Natural Human Isolate of Lactobacillus jensenii Engineered to Express Functional Two-Domain CD4

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 100; no. 20; pp. 11672 - 11677
• Main Authors: Theresa L. -Y. Chang, Chang, Chia-Hwa, Simpson, David A., Xu, Qiang, Martin, Patrick K., Lagenaur, Laurel A., Schoolnik, Gary K., Ho, David D., Hillier, Sharon L., Holodniy, Mark, Lewicki, John A., Lee, Peter P.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 30.09.2003; National Acad Sciences
• Subjects: Antibodies; Antiviral Agents; Bacteria; Base Sequence; Biological Sciences; Body fluids; CD4 Antigens - genetics; DNA Primers; Enzyme-Linked Immunosorbent Assay; Escherichia coli - genetics; Female; HeLa cells; HIV; HIV 1; HIV Infections - transmission; HIV-1 - pathogenicity; Human immunodeficiency virus; Humans; Lactobacillus; Lactobacillus - genetics; Lactobacillus - isolation & purification; Membrane Fusion; Microbiology; Plasmids; Protein refolding; Proteins; Vagina - microbiology; Viruses
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1934747100

The predominant mode of HIV transmission worldwide is via heterosexual contact, with the cervico-vaginal mucosa being the main portal of entry in women. The cervico-vaginal mucosa is naturally colonized with commensal bacteria, primarily lactobacilli. To address the urgent need for female-controlled approaches to block the heterosexual transmission of HIV, we have engineered natural human vaginal isolates of Lactobacillus jensenii to secrete two-domain CD4 (2D CD4) proteins. The secreted 2D CD4 recognized a conformation-dependent anti-CD4 antibody and bound HIV type 1 (HIV-1) gp120, suggesting that the expressed proteins adopted a native conformation. Single-cycle infection assays using HIV-1HxB2carrying a luciferase reporter gene demonstrated that Lactobacillus-derived 2D CD4 inhibited HIV-1 entry into target cells in a dose-dependent manner. Importantly, coincubation of the engineered bacteria with recombinant HIV-1HxB2reporter virus led to a significant decrease in virus infectivity of HeLa cells expressing CD4-CXCR4-CCR5. Engineered lactobacilli also caused a modest, but statistically significant, decrease in infectivity of a primary isolate, HIV-1JR-FL. This represents an important first step toward the development of engineered commensal bacteria within the vaginal microflora to inhibit heterosexual transmission of HIV.