A native-like SOSIP.664 trimer based on an HIV-1 subtype B env gene

Area of Science:

• Immunology
• Virology
• Structural Biology

Background:

• The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) is a key target for neutralizing antibodies.
• Recombinant, soluble, native-like Env trimers are crucial for developing effective HIV-1 vaccines.
• Current vaccine strategies often utilize BG505 subtype A SOSIP.664 trimers, but a broader range of subtype-specific trimers is needed.

Purpose of the Study:

• To produce and characterize a novel subtype B HIV-1 SOSIP.664 gp140 trimer derived from the B41 env gene.
• To develop a method for producing intact, non-proteolytically cleaved trimers in low-serum media.
• To establish a purification strategy for native-like trimers using a broadly neutralizing antibody (bNAb).

Main Methods:

• Production of a subtype B (B41) SOSIP.664 gp140 trimer in low-serum media.
• Purification of non-clipped trimers using affinity chromatography with the bNAb PGT145.
• Negative-stain electron microscopy to analyze trimer conformation.

Main Results:

• Successful production of a stable, cleaved subtype B (B41) SOSIP.664 gp140 trimer.
• Development of a method to prevent V3 loop proteolytic damage during production.
• Demonstration of efficient purification of intact trimers using PGT145 affinity chromatography.
• Identification of two conformational states (closed and intermediate) in purified trimers via electron microscopy.

Conclusions:

• The B41 SOSIP.664 trimer represents a valuable addition to the available native-like Env proteins for HIV-1 vaccine research.
• The developed purification method using PGT145 is effective for obtaining structurally intact trimers.
• These findings facilitate further structural and immunogenicity studies crucial for designing an effective HIV-1 vaccine.