De Novo Assembly of H3L and A17L Epitopes for the Rapid Development of Clade 1b MPOX Countermeasures for Africa

Abstract

Background: An outbreak of Mpox disease caused by a mutant clade 1b virus (MPXV) in Kamituga area, South Kivu Province, DRC has rapidly grown to involve neighboring countries in this region. This now has the authorities worried, due to the limited supply of Mpox vaccines with emergence use licensure (EUL) available. As an emergency local response to this challenge, we set out to identify epitopes of clade 1b MPXV surface proteins as targets for the rapid research and development (R & D) of Mpox medical countermeasures. Methods: The H3L (OPG108–heparin binding protein) and A17L (OPG143–myristylated protein) were selected by virtue of their surface localization, stability and known role in MPXV host cell fusion entry. Within the immune epitope database analysis resource (IEDB-AR), surface accessibility, antigenicity and 3-D localisation (DiscoTope) we examined to identify > 9-nomer epitopes Results: Three (3) and six(6) candidate >9-nomer epitopes were derived for H3L and A17L surface fusion protein. Across all parameters, the two best identified epitopes were as follows:—H3L (28-HINDQKFDDVKDNEVMQEKR-47 and 236-YVEHDPRLVAEH-247) and A17L (104-QNEVTPEYIKDLKYATDYIA-123;) 270-KKDYLLGDSDSVAKCCSKTNTKHCPKIFNNNYKTEHC-290). Conclusions: These epitopes— alone, multiplexed (say as a nano-spiked virus-like particles, VLPs) or fused as a chimeric recombinants form immunogens for the rapid production of protein sub-unit vaccines. Inversely, derivative monoclonal antibodies (mAbs) from the same are precursors for therapeutic cocktails and or antigen, rapid diagnostic tests (RDT).