Potent HIV-1 miniprotein inhibitors targeting highly conserved gp41 epitopes

Area of Science:

• Virology
• Structural Biology
• Immunology

Background:

• HIV entry relies on the viral envelope glycoprotein (Env), specifically gp41 subunit assembly into a six-helix bundle (6HB).
• Formation of the 6HB is crucial for bringing viral and cell membranes together, facilitating HIV infection.
• Inhibiting 6HB formation is a key strategy to block HIV-1 replication.

Purpose of the Study:

• To design and develop novel chimeric miniproteins (covNHR-N) that inhibit HIV-1 entry.
• To enhance the stability and inhibitory activity of previously developed miniproteins.
• To explore the synergistic potential of these miniproteins with broadly neutralizing antibodies (bNAbs).

Main Methods:

• Design of new covNHR-N miniproteins with enhanced stabilization via polar-to-hydrophobic mutations.
• Incorporation of structural motifs targeting the membrane proximal external region (MPER) of gp41.
• Assessment of binding affinity to gp41 peptides and HIV-1 inhibitory activity against primary viruses in peripheral blood mononuclear cells (PBMC).

Main Results:

• Novel miniproteins demonstrated increased binding affinity for gp41-derived peptides.
• Enhanced HIV-1 inhibitory activity was observed, particularly against infectious primary viruses.
• Significant synergy was found between the miniproteins and bNAbs, reducing viral replication in ex vivo experiments.

Conclusions:

• The newly designed, stabilized miniproteins represent a potent strategy for inhibiting HIV-1 entry.
• These miniproteins show promise for combination therapy, particularly with bNAbs.
• Further development of these miniproteins could lead to novel anti-HIV-1 drug compositions.