A Nonfusogenic Antigen Mimic of Influenza Hemagglutinin Glycoproteins Constituted with Soluble Full-Length HA1 and Truncated HA2 Proteins Expressed in E. coli

• Published in: Molecular biotechnology Vol. 57; no. 2; pp. 128 - 137
• Main Authors: Kim, Chang Sup, Park, Youn-Je
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.02.2015; Springer Nature B.V
• Subjects: Animals; Antibodies, Neutralizing - genetics; Antibodies, Neutralizing - immunology; Antibodies, Viral; Antigens; Biochemistry; Biological Techniques; Biotechnology; Body weight; Cell Biology; Chemistry; Chemistry and Materials Science; E coli; Escherichia coli; Glycoproteins; Hemagglutinin Glycoproteins, Influenza Virus - genetics; Hemagglutinin Glycoproteins, Influenza Virus - immunology; Hemagglutinin Glycoproteins, Influenza Virus - therapeutic use; Human Genetics; Humans; Immunization; Influenza A virus; Influenza A Virus, H3N2 Subtype - immunology; Influenza, Human - genetics; Influenza, Human - immunology; Influenza, Human - prevention & control; Influenza, Human - virology; Mice; Peptides; Protein expression; Protein Science; Vaccines; Vaccines, Synthetic - immunology; Antigen mimic; Nonfusogenic; Fusion peptide; Influenza hemagglutinin; Recombinant vaccine
• ISSN: 1073-6085; 1559-0305
• DOI: 10.1007/s12033-014-9808-3

A novel method is proposed to produce a soluble recombinant antigen mimic, constituted with full-length HA1 and truncated HA2 individually expressed in E. coli , instead of a precursor form of hemagglutinin protein, that is similar to the naturally processed and disulfide-linked HA1/HA2 on the envelope of the influenza A virus strain X-31 (H3N2). A truncated ectodomain of HA2 subunit, HA2(23–185)/C137S, lacked two membrane-interacting sequences, i.e., the N-terminal fusion peptide as well as the transmembrane domain and short cytoplasmic segment at the C terminus. A recombinant HA1 (rHA1) subunit protein, HA1(1–328)/C14S/L157S, lacked the signal peptide. Mutations C137S and C14S in the HA2 and HA1 subunits, respectively, were introduced to prevent any possible disulfide linkage between the two subunit proteins. The rHA antigen mimic would be nonfusogenic mainly due to the absence of the N-terminal fusion peptide as well as the C-terminal transmembrane domain in the truncated HA2, and eventually less cytotoxic as well. Antibody responses induced by two soluble rHA antigens were evaluated by ELISA assays to detect rHA antigens injected and to validate both anti-HA1 and anti-HA2 antibodies produced in the mice sera. Antigenic rHA proteins also elicited neutralizing antibodies against homologous H3N2 influenza virus in the immunized mice, without severe body weight loss or any other adverse symptoms.