Streptococcus pneumoniae pneumococcal surface protein A (PspA) and pneumolysin (Ply) (PspA/Ply)

Streptococcus pneumoniae pneumococcal surface protein A (PspA) and pneumolysin (Ply) are two critical virulence factors targeted in the development of next-generation protein-based vaccines. PspA is a highly immunogenic surface protein that prevents host complement deposition (specifically C3), thereby allowing the bacteria to evade opsonophagocytosis (Source: PubMed, PMID: 11553475). It is categorized into families and clades; targeting clades 2, 3, and 4 ensures broad coverage across the most prevalent clinical strains of pneumococci (Source: PubMed, PMID: 25216656). Pneumolysin is a potent intracellular toxin released during bacterial lysis that forms pores in cholesterol-containing host membranes, leading to cell death and exaggerated inflammatory responses (Source: UniProt, P0C2J9). By combining specific PspA clades with a detoxified version of pneumolysin, researchers aim to create a vaccine that provides serotype-independent protection by both enhancing bacterial clearance and neutralizing toxin-mediated tissue damage. This multi-antigen approach is designed to overcome the limitations of current polysaccharide-conjugate vaccines, such as serotype replacement and high production costs (Source: PubMed, PMID: 30639475).

Other names

PspAPlyPneumolysinPneumococcal surface protein APspA clades 2, 3, and 4Pneumococcal vaccine antigen combination

Induction of opsonophagocytic antibodies against PspA to enhance bacterial clearance and neutralizing antibodies against Ply to prevent host cell lysis and inflammation.