Streptococcus pneumoniae serotype-specific pneumococcal protein SPP2 (SPP2)

SPP2 is a novel pneumococcal fusion protein developed by Affinivax (now part of GSK) as a key component of next-generation vaccines using the Multiple Antigen Presenting System (MAPS) technology. It is a recombinant protein comprising a biotin-binding domain (rhizavidin) fused to two conserved Streptococcus pneumoniae antigens: the translation elongation factor P (SP0435) and a genetically detoxified mutant of pneumolysin (Ply), also known as a pneumolysin toxoid. The primary biological function of SPP2 is to elicit potent neutralizing antibodies against the pneumolysin toxin, a major virulence factor that causes host cell lysis and inflammation. Additionally, SPP2 provides T-cell epitopes to enhance the overall immunogenicity of the vaccine. A critical therapeutic role of SPP2 is its ability to provide synergistic protection against invasive pneumococcal disease caused by serotype 3 (ST-3), a serotype that is notoriously resistant to traditional conjugate vaccines. By combining SPP2 with pneumococcal capsular polysaccharides, MAPS-based vaccines aim to provide broader and more robust protection against a wide range of pneumococcal infections, including pneumonia, meningitis, and sepsis.

Other names

Pneumococcal fusion protein SPP2SPP2PdF-rhizavidin fusion proteinRhizavidin-SP0435-PdT fusion proteinSerotype-specific pneumococcal protein 2

Induction of neutralizing antibodies against pneumolysin toxin; Synergistic enhancement of opsonophagocytic activity against serotype 3; Activation of T-cell mediated immunity