Respiratory syncytial virus fusion glycoprotein expressed in insect cells form protein nanoparticles that induce protective immunity in cotton rats

• Published in: PloS one 2012-11, Vol.7 (11), p.e50852
• Main Authors: Smith, Gale, Raghunandan, Rama, Wu, Yingyun, Liu, Ye, Massare, Michael, Nathan, Margret, Zhou, Bin, Lu, Hanxin, Boddapati, Sarathi, Li, Jingning, Flyer, David, Glenn, Gregory
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino acids; Animals; Antibodies, Monoclonal, Humanized - immunology; Antibodies, Viral - immunology; Antigenic determinants; Antigens; Baculovirus; Biology; Biopolymers; Cell membranes; Children; Chromatography, High Pressure Liquid; Cloning; Cotton; Disease; Disease Models, Animal; Epitopes; Formaldehyde; Geriatrics; Glycoproteins; Glycoproteins - immunology; Humans; Immunity; Immunity - immunology; Immunization; Immunogenicity; Immunoglobulin G; Immunoglobulins; Infants; Infections; Insect cells; Insects; Laboratory animals; Light; Lung - pathology; Lung - virology; Lungs; Male; Medical laboratories; Medicine; Membranes; Monoclonal antibodies; Mutant Proteins - chemistry; Mutant Proteins - immunology; Mutation; Nanoparticles; Nanoparticles - chemistry; Nanoparticles - ultrastructure; Neutralizing; Older people; Oligomers; Palivizumab; Pediatric diseases; Polypeptides; Protein Structure, Tertiary; Proteins; Rats; Respiratory syncytial virus; Respiratory Syncytial Virus Infections - immunology; Respiratory Syncytial Virus Infections - prevention & control; Respiratory Syncytial Viruses - immunology; Respiratory tract; Respiratory tract diseases; Scattering, Radiation; Sf9 Cells; Sigmodon; Sigmodontinae - immunology; Sigmodontinae - virology; Surface Plasmon Resonance; Vaccines; Viral Fusion Proteins - chemistry; Viral Fusion Proteins - immunology; Viral Fusion Proteins - isolation & purification; Viruses
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0050852

Respiratory Syncytial Virus (RSV) is an important viral agent causing severe respiratory tract disease in infants and children as well as in the elderly and immunocompromised individuals. The lack of a safe and effective RSV vaccine represents a major unmet medical need. RSV fusion (F) surface glycoprotein was modified and cloned into a baculovirus vector for efficient expression in Sf9 insect cells. Recombinant RSV F was glycosylated and cleaved into covalently linked F2 and F1 polypeptides that formed homotrimers. RSV F extracted and purified from insect cell membranes assembled into 40 nm protein nanoparticles composed of multiple RSV F oligomers arranged in the form of rosettes. The immunogenicity and protective efficacy of purified RSV F nanoparticles was compared to live and formalin inactivated RSV in cotton rats. Immunized animals induced neutralizing serum antibodies, inhibited virus replication in the lungs, and had no signs of disease enhancement in the respiratory track of challenged animals. RSV F nanoparticles also induced IgG competitive for binding of palivizumab neutralizing monoclonal antibody to RSV F antigenic site II. Antibodies to this epitope are known to protect against RSV when passively administered in high risk infants. Together these data provide a rational for continued development a recombinant RSV F nanoparticle vaccine candidate.