5UTY

Crystal Structure of a Stabilized DS-SOSIP.mut4 BG505 gp140 HIV-1 Env Trimer, Containing Mutations I201C-P433C (DS), L154M, N300M, N302M, T320L in Complex with Human Antibodies PGT122 and 35O22 at 4.1 Angstrom

Summary for 5UTY

• Entry DOI: 10.2210/pdb5uty/pdb
• Descriptor: HIV-1 BG505 strain Env gp41, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (13 entities in total)
• Functional Keywords: hiv-1 env, stabilized env, near-native mimic of the viral spike, viral protein-immune system complex, viral protein/immune system
• Biological source: Human immunodeficiency virus 1; More
• Total number of polymer chains: 6
• Total formula weight: 182202.18

Authors

Xu, K.,Chuang, G.-Y.,Pancera, M.,Kwong, P.D. (deposition date: 2017-02-15, release date: 2017-03-29, Last modification date: 2024-10-16)

Primary citation

Chuang, G.Y.,Geng, H.,Pancera, M.,Xu, K.,Cheng, C.,Acharya, P.,Chambers, M.,Druz, A.,Tsybovsky, Y.,Wanninger, T.G.,Yang, Y.,Doria-Rose, N.A.,Georgiev, I.S.,Gorman, J.,Joyce, M.G.,O'Dell, S.,Zhou, T.,McDermott, A.B.,Mascola, J.R.,Kwong, P.D.
Structure-Based Design of a Soluble Prefusion-Closed HIV-1 Env Trimer with Reduced CD4 Affinity and Improved Immunogenicity.
J. Virol., 91:-, 2017

PubMed Abstract: 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. 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.

PubMed: 28275193
DOI: 10.1128/JVI.02268-16

Experimental method

X-RAY DIFFRACTION (3.412 Å)