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Structure-Based Design of a Soluble Prefusion-Closed HIV-1 Env Trimer with Reduced CD4 Affinity and Improved Immunogenicity.

Publication ,  Journal Article
Chuang, G-Y; Geng, H; Pancera, M; Xu, K; Cheng, C; Acharya, P; Chambers, M; Druz, A; Tsybovsky, Y; Wanninger, TG; Yang, Y; Doria-Rose, NA ...
Published in: J Virol
May 15, 2017

The HIV-1 envelope (Env) trimer is a target for vaccine design as well as a conformational machine that facilitates virus entry by transitioning between prefusion-closed, CD4-bound, and coreceptor-bound conformations by transitioning into a postfusion state. Vaccine designers have sought to restrict the conformation of the HIV-1 Env trimer to its prefusion-closed state as this state is recognized by most broadly neutralizing, but not nonneutralizing, antibodies. We previously identified a disulfide bond, I201C-A433C (DS), which stabilizes Env in the vaccine-desired prefusion-closed state. When placed into the context of BG505 SOSIP.664, a soluble Env trimer mimic developed by Sanders, Moore, and colleagues, the engineered DS-SOSIP trimer showed reduced conformational triggering by CD4. Here, we further stabilize DS-SOSIP through a combination of structure-based design and 96-well-based expression and antigenic assessment. From 103 designs, we identified one, named DS-SOSIP.4mut, with four additional mutations at the interface of potentially mobile domains of the prefusion-closed structure. We also determined the crystal structures of DS-SOSIP.4mut at 4.1-Å resolution and of an additional DS-SOSIP.6mut variant at 4.3-Å resolution, and these confirmed the formation of engineered disulfide bonds. Notably, DS-SOSIP.4mut elicited a higher ratio of tier 2 autologous titers versus tier 1 V3-sensitive titers than BG505 SOSIP.664. DS-SOSIP.4mut also showed reduced recognition of CD4 and increased thermostability. The improved antigenicity, thermostability, and immunogenicity of DS-SOSIP.4mut suggest utility as an immunogen or a serologic probe; moreover, the specific four alterations identified here, M154, M300, M302, and L320 (4mut), can also be transferred to other HIV-1 Env trimers of interest to improve their properties.IMPORTANCE One approach to elicit broadly neutralizing antibodies against HIV-1 is to stabilize the structurally flexible HIV-1 envelope (Env) trimer in a conformation that displays predominantly broadly neutralizing epitopes and few to no nonneutralizing epitopes. The prefusion-closed conformation of HIV-1 Env has been identified as one such preferred conformation, and a current leading vaccine candidate is the BG505 DS-SOSIP variant, comprising two disulfides and an Ile-to-Pro mutation of Env from strain BG505. Here, we introduced additional mutations to further stabilize BG505 DS-SOSIP in the vaccine-preferred prefusion-closed conformation. In guinea pigs, our best mutant, DS-SOSIP.4mut, elicited a significantly higher ratio of autologous versus V3-directed neutralizing antibody responses than the SOSIP-stabilized form. We also observed an improvement in thermostability and a reduction in CD4 affinity. With improved antigenicity, stability, and immunogenicity, DS-SOSIP.4mut-stabilized trimers may have utility as HIV-1 immunogens or in other antigen-specific contexts, such as with B-cell probes.

Duke Scholars

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Published In

J Virol

DOI

EISSN

1098-5514

Publication Date

May 15, 2017

Volume

91

Issue

10

Location

United States

Related Subject Headings

  • env Gene Products, Human Immunodeficiency Virus
  • Virology
  • Protein Stability
  • Protein Multimerization
  • Humans
  • HIV-1
  • HIV Antigens
  • HIV Antibodies
  • Guinea Pigs
  • CD4 Antigens
 

Citation

APA
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ICMJE
MLA
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Chuang, G.-Y., Geng, H., Pancera, M., Xu, K., Cheng, C., Acharya, P., … Kwong, P. D. (2017). Structure-Based Design of a Soluble Prefusion-Closed HIV-1 Env Trimer with Reduced CD4 Affinity and Improved Immunogenicity. J Virol, 91(10). https://doi.org/10.1128/JVI.02268-16
Chuang, Gwo-Yu, Hui Geng, Marie Pancera, Kai Xu, Cheng Cheng, Priyamvada Acharya, Michael Chambers, et al. “Structure-Based Design of a Soluble Prefusion-Closed HIV-1 Env Trimer with Reduced CD4 Affinity and Improved Immunogenicity.J Virol 91, no. 10 (May 15, 2017). https://doi.org/10.1128/JVI.02268-16.
Chuang G-Y, Geng H, Pancera M, Xu K, Cheng C, Acharya P, et al. Structure-Based Design of a Soluble Prefusion-Closed HIV-1 Env Trimer with Reduced CD4 Affinity and Improved Immunogenicity. J Virol. 2017 May 15;91(10).
Chuang, Gwo-Yu, et al. “Structure-Based Design of a Soluble Prefusion-Closed HIV-1 Env Trimer with Reduced CD4 Affinity and Improved Immunogenicity.J Virol, vol. 91, no. 10, May 2017. Pubmed, doi:10.1128/JVI.02268-16.
Chuang G-Y, Geng H, Pancera M, Xu K, Cheng C, Acharya P, Chambers M, Druz A, Tsybovsky Y, Wanninger TG, Yang Y, Doria-Rose NA, Georgiev IS, Gorman J, Joyce MG, O’Dell S, Zhou T, McDermott AB, Mascola JR, Kwong PD. Structure-Based Design of a Soluble Prefusion-Closed HIV-1 Env Trimer with Reduced CD4 Affinity and Improved Immunogenicity. J Virol. 2017 May 15;91(10).

Published In

J Virol

DOI

EISSN

1098-5514

Publication Date

May 15, 2017

Volume

91

Issue

10

Location

United States

Related Subject Headings

  • env Gene Products, Human Immunodeficiency Virus
  • Virology
  • Protein Stability
  • Protein Multimerization
  • Humans
  • HIV-1
  • HIV Antigens
  • HIV Antibodies
  • Guinea Pigs
  • CD4 Antigens