title: Antigenicity and immunogenicity of RV144 vaccine AIDSVAX clade E envelope immunogen is enhanced by a gp120 N-terminal deletion.
abstract: An immune correlates analysis of the RV144 HIV-1 vaccine trial revealed that antibody responses to the gp120 V1/V2 region correlated inversely with infection risk. The RV144 protein immunogens (A244-rp120 and MN-rgp120) were modified by an N-terminal 11-amino-acid deletion (Δ11) and addition of a herpes simplex virus (HSV) gD protein-derived tag (gD). We investigated the effects of these modifications on gp120 expression, antigenicity, and immunogenicity by comparing unmodified A244 gp120 with both Δ11 deletion and gD tag and with Δ11 only. Analysis of A244 gp120, with or without Δ11 or gD, demonstrated that the Δ11 deletion, without the addition of gD, was sufficient for enhanced antigenicity to gp120 C1 region, conformational V2, and V1/V2 gp120 conformational epitopes. RV144 vaccinee serum IgGs bound more avidly to A244 gp120 Δ11 than to the unmodified gp120, and their binding was blocked by C1, V2, and V1/V2 antibodies. Rhesus macaques immunized with the three different forms of A244 gp120 proteins gave similar levels of gp120 antibody titers, although higher antibody titers developed earlier in A244 Δ11 gp120-immunized animals. Conformational V1/V2 monoclonal antibodies (MAbs) gave significantly higher levels of blocking of plasma IgG from A244 Δ11 gp120-immunized animals than IgG from animals immunized with unmodified A244 gp120, thus indicating a qualitative difference in the V1/V2 antibodies induced by A244 Δ11 gp120. These results demonstrate that deletion of N-terminal residues in the RV144 A244 gp120 immunogen improves both envelope antigenicity and immunogenicity.
authors.affiliation: Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, USA. alam0004@mc.duke.edu
authors.forename: S Munir
authors.initials: SM
authors.lastname: Alam
authors.forename: Hua-Xin
authors.initials: HX
authors.lastname: Liao
authors.forename: Georgia D
authors.initials: GD
authors.lastname: Tomaras
authors.forename: Mattia
authors.initials: M
authors.lastname: Bonsignori
authors.forename: Chun-Yen
authors.initials: CY
authors.lastname: Tsao
authors.forename: Kwan-Ki
authors.initials: KK
authors.lastname: Hwang
authors.forename: Haiyan
authors.initials: H
authors.lastname: Chen
authors.forename: Krissey E
authors.initials: KE
authors.lastname: Lloyd
authors.forename: Cindy
authors.initials: C
authors.lastname: Bowman
authors.forename: Laura
authors.initials: L
authors.lastname: Sutherland
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Jeffries
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Kozink
authors.forename: Shelley
authors.initials: S
authors.lastname: Stewart
authors.forename: Kara
authors.initials: K
authors.lastname: Anasti
authors.forename: Frederick H
authors.initials: FH
authors.lastname: Jaeger
authors.forename: Robert
authors.initials: R
authors.lastname: Parks
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Yates
authors.forename: R Glenn
authors.initials: RG
authors.lastname: Overman
authors.forename: Faruk
authors.initials: F
authors.lastname: Sinangil
authors.forename: Phillip W
authors.initials: PW
authors.lastname: Berman
authors.forename: Punnee
authors.initials: P
authors.lastname: Pitisuttithum
authors.forename: Jaranit
authors.initials: J
authors.lastname: Kaewkungwal
authors.forename: Sorachai
authors.initials: S
authors.lastname: Nitayaphan
authors.forename: Nicos
authors.initials: N
authors.lastname: Karasavva
authors.forename: Supachai
authors.initials: S
authors.lastname: Rerks-Ngarm
authors.forename: Jerome H
authors.initials: JH
authors.lastname: Kim
authors.forename: Nelson L
authors.initials: NL
authors.lastname: Michael
authors.forename: Susan
authors.initials: S
authors.lastname: Zolla-Pazner
authors.forename: Sampa
authors.initials: S
authors.lastname: Santra
authors.forename: Norman L
authors.initials: NL
authors.lastname: Letvin
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Harrison
authors.forename: Barton F
authors.initials: BF
authors.lastname: Haynes
mesh_terms: D016915:AIDS Vaccines / Q000235:genetics / Q000276:immunology*; D000818:Animals; D000915:Antibody Affinity; D000939:Epitopes / Q000276:immunology; D015483:HIV Antibodies / Q000097:blood / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008253:Macaca mulatta; D017384:Sequence Deletion
chemical_list: D016915:AIDS Vaccines; C112734:AIDSVAX; D000939:Epitopes; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; C514793:gp120 protein, Human immunodeficiency virus 1