Structure-Based Stabilization of SOSIP Env Enhances Recombinant Ectodomain Durability and Yield.

Area of Science:

• Structural biology
• Virology
• Immunology

Background:

• The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) is crucial for viral entry and a primary target for vaccine development.
• Recombinant expression of metastable Env proteins is challenging, hindering biochemical and immunological studies essential for vaccine design.
• Existing methods for stabilizing Env proteins have limitations in yield and applicability.

Purpose of the Study:

• To develop a novel stabilization strategy for producing prefusion Env trimers of HIV-1.
• To enhance the yield and stability of recombinant Env ectodomains for vaccine research.
• To assess the broad applicability of the new stabilization strategy across diverse Env variants.

Main Methods:

• Introduction of a novel proline-based stabilization strategy, termed '2P'.
• Synergistic application of the 2P strategy with existing SOSIP mutations.
• Assessment of Env ectodomain yield, conformational properties, and antigenic characteristics.

Main Results:

• The 2P strategy significantly increases the yield of recombinantly expressed Env ectodomains.
• The 2P mutations enhance the durability of the prefusion Env conformation.
• The stabilization strategy is effective across evolutionarily and antigenically diverse HIV-1 Env constructs without altering key antigenic properties.

Conclusions:

• The 2P proline stabilization strategy provides a robust platform for producing stable prefusion HIV-1 Env trimers.
• This approach overcomes previous limitations in Env protein expression, facilitating biochemical research.
• The 2P strategy broadens the scope of Env variants suitable for HIV-1 vaccine development.