title: Inhibition of HIV infectivity by a natural human isolate of Lactobacillus jensenii engineered to express functional two-domain CD4.
abstract: 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-1HxB2 carrying 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-1HxB2 reporter 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.
authors.affiliation: Osel, Inc., 1800 Wyatt Drive, Suite 14, Santa Clara, CA 95054, USA.
authors.forename: Theresa L-Y
authors.initials: TL
authors.lastname: Chang
authors.forename: Chia-Hwa
authors.initials: CH
authors.lastname: Chang
authors.forename: David A
authors.initials: DA
authors.lastname: Simpson
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xu
authors.forename: Patrick K
authors.initials: PK
authors.lastname: Martin
authors.forename: Laurel A
authors.initials: LA
authors.lastname: Lagenaur
authors.forename: Gary K
authors.initials: GK
authors.lastname: Schoolnik
authors.forename: David D
authors.initials: DD
authors.lastname: Ho
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Hillier
authors.forename: Mark
authors.initials: M
authors.lastname: Holodniy
authors.forename: John A
authors.initials: JA
authors.lastname: Lewicki
authors.forename: Peter P
authors.initials: PP
authors.lastname: Lee
mesh_terms: D000998:Antiviral Agents; D001483:Base Sequence; D015704:CD4 Antigens / Q000235:genetics*; D017931:DNA Primers; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics; D005260:Female; D015658:HIV Infections / Q000635:transmission; D015497:HIV-1 / Q000472:pathogenicity*; D006801:Humans; D007778:Lactobacillus / Q000235:genetics* / Q000302:isolation & purification; D008561:Membrane Fusion; D014621:Vagina / Q000382:microbiology
chemical_list: D000998:Antiviral Agents; D015704:CD4 Antigens; D017931:DNA Primers