Solid-Phase Synthesis of a Branched Peptide to Form a Homo-Two-Stranded Coiled-Coil for the Development of a Universal Flu Vaccine

摘要

Millions of people worldwide are infected with influenza virus, resulting in 250,000-500,000 deaths annually [1]. Efforts to combat the virus through vaccination are repeatedly thwarted by mutations of the antigenic viral proteins hemagglutinin (HA) and/or neuraminidase (NA) [2]. Our goal is to develop a "Universal Flu Vaccine" that will provide long-lasting protection against heterotypic strains of influenza A virus. We have developed synthetic peptide immunogens based on helical regions of the HA protein that are conserved across a diverse range of influenza A virus strains. Our immunogens are 2-stranded α-helical coiled-coils, which form stabilized helical epitopes for the generation of protective antibodies in vivo. Helical segments of the HA protein in its pre-fusion state were inserted into our 2-stranded coiled-coil template. Our previously reported strategy of immunogen formation [3,4] required 18 distinct steps to assemble the peptide immunogen conjugated to a carner protein. Product yield was decreased due to the number of steps and low yields of specific steps required to form the carrier conjugated peptide immunogen. The branched peptide immunogen was designed to overcome synthetic and purification challenges and to increase the efficiency of product formation by significantly decreasing the number of steps required to form the final conjugated immunogen.