Protection of mice against a lethal influenza challenge by immunization with yeast‐derived recombinant influenza neuraminidase

摘要: The head domain of recombinant neuraminidase of A/Victoria/3/75 influenza virus was produced in a secreted form in the methylotrophic yeast Pichia pastoris using the P. pastoris alcohol oxidase 1 promoter and the Saccharomyces cerevisiaeα‐mating‐factor signal sequence. Cultures in shake flasks provided expression levels of approximately 2.5–3 mg/1. Recombinant neuraminidase was purified from the culture medium to over 99% homogeneity. Although P. pastoris‐secreted products are believed to carry shorter N‐linked carbohydrate side chains than glycoproteins of S. cerevisiae, secreted neuraminidase was hyperglycosylated, with N‐glycans of the high‐mannose type containing up to 30–40 mannose residues. N‐glycans were phosphorylated and only partially sensitive to α‐mannosidase treatment. Balb/c mice immunized three times with 2 μg purified recombinant neuraminidase were 50% protected …