Structural basis of Zika virus NS1 multimerization and human antibody recognition

Area of Science:

• Virology
• Structural Biology
• Immunology

Background:

• Zika virus (ZIKV) outbreaks cause neurological issues and birth defects, unmet needs for vaccines and antivirals exist.
• ZIKV non-structural protein 1 (NS1) is linked to disease severity and diagnosis but its structure and function are unclear.
• Distinguishing recombinant secreted NS1 (rsNS1) from infection-derived secreted NS1 (isNS1) is crucial.

Purpose of the Study:

• Determine the high-resolution structure of ZIKV NS1.
• Investigate ZIKV NS1 interactions with human monoclonal antibodies.
• Elucidate the role of ZIKV NS1 in pathogenesis and antibody-mediated protection.

Main Methods:

• High-resolution cryo-electron microscopy (cryoEM) for ZIKV rsNS1 structure determination.
• CryoEM analysis of ZIKV rsNS1 complexes with human monoclonal antibodies (AA12, EB9, GB5).
• Investigation of ZIKV isNS1 binding to High Density Lipoprotein (HDL).

Main Results:

• ZIKV rsNS1 forms tetramers and filamentous repeats of tetramers.
• Antibody binding to ZIKV NS1 did not disrupt the tetrameric structure.
• Antibodies targeted the wing and connector subdomain of the NS1 β-ladder.
• Evidence of ZIKV isNS1 binding to HDL was observed.

Conclusions:

• The study reveals insights into ZIKV NS1 multimerization and structure.
• Antibody binding mechanisms against ZIKV NS1 are elucidated.
• Understanding ZIKV NS1 polymorphism is highlighted for therapeutic development.
• The findings expand the mechanistic basis for antibody-based protection against ZIKV.