title: Preformulation characterization of an aluminum salt-adjuvanted trivalent recombinant protein-based vaccine candidate against Streptococcus pneumoniae.
abstract: The preformulation of a trivalent recombinant protein-based vaccine candidate for protection against Streptococcus pneumoniae is described both in the presence and in the absence of aluminum salt adjuvants. The biophysical properties of the three protein-based antigens, fragments of pneumococcal surface adhesion A (PsaA), serine-threonine protein kinase (StkP), and protein required for cell wall separation of group B streptococcus (PcsB), were studied using several spectroscopic and light scattering techniques. An empirical phase diagram was constructed to assess the overall conformational stability of the three antigens as a function of pH and temperatures. A variety of excipients were screened on the basis of their ability to stabilize each antigen using intrinsic fluorescence spectroscopy and circular dichroism spectroscopy. Sorbitol, sucrose, and trehalose stabilized the three proteins in solution. The addition of manganese also showed a drastic increase in the thermal stability of SP1650 in solution. The adsorption and desorption processes of each of the antigens to aluminum salt adjuvants were evaluated, and the stability of the adsorbed proteins was then assessed using intrinsic fluorescence spectroscopy and Fourier transform infrared spectroscopy. All the three proteins showed good adsorption to Alhydrogel. PsaA was destabilized when adsorbed onto Alhydrogel® and adding sodium phosphate showed a stabilizing effect. PcsB was found to be stabilized when adsorbed to Alhydrogel®, and no destabilizing or stabilizing effects were seen in the case of StkP.
authors.affiliation: Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas 66045, USA.
authors.forename: Vidyashankara
authors.initials: V
authors.lastname: Iyer
authors.forename: Lei
authors.initials: L
authors.lastname: Hu
authors.forename: Mangala Roshan
authors.initials: MR
authors.lastname: Liyanage
authors.forename: Reza
authors.initials: R
authors.lastname: Esfandiary
authors.forename: Christoph
authors.initials: C
authors.lastname: Reinisch
authors.forename: Andreas
authors.initials: A
authors.lastname: Meinke
authors.forename: Jeff
authors.initials: J
authors.lastname: Maisonneuve
authors.forename: David B
authors.initials: DB
authors.lastname: Volkin
authors.forename: Sangeeta B
authors.initials: SB
authors.lastname: Joshi
authors.forename: C Russell
authors.initials: CR
authors.lastname: Middaugh
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry; D000276:Adjuvants, Immunologic / Q000737:chemistry*; D000327:Adsorption; D017607:Aluminum Compounds / Q000737:chemistry* / Q000276:immunology; D000536:Aluminum Hydroxide / Q000737:chemistry* / Q000276:immunology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000276:immunology; D002626:Chemistry, Pharmaceutical; D002942:Circular Dichroism; D005079:Excipients / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008027:Light; D008074:Lipoproteins / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry* / Q000276:immunology; D022242:Pneumococcal Vaccines / Q000737:chemistry* / Q000276:immunology; D011487:Protein Conformation; D011489:Protein Denaturation; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry; D055550:Protein Stability; D012542:Scattering, Radiation; D013012:Sorbitol / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013296:Streptococcus pneumoniae / Q000276:immunology*; D013395:Sucrose / Q000737:chemistry; D013678:Technology, Pharmaceutical / Q000379:methods; D013696:Temperature; D014199:Trehalose / Q000737:chemistry; D014614:Vaccines, Synthetic / Q000737:chemistry
chemical_list: D018829:Adhesins, Bacterial; D000276:Adjuvants, Immunologic; D017607:Aluminum Compounds; D001426:Bacterial Proteins; D005079:Excipients; D008074:Lipoproteins; D010710:Phosphates; D022242:Pneumococcal Vaccines; C085000:PsaA protein, Streptococcus; D014614:Vaccines, Synthetic; D013012:Sorbitol; D013395:Sucrose; D000536:Aluminum Hydroxide; D014199:Trehalose; D017346:Protein Serine-Threonine Kinases; C012714:aluminum phosphate