Group B Streptococcus C5a peptidase (ScpB) (ScpB)

Group B Streptococcus C5a peptidase (ScpB) is a surface-anchored serine protease expressed by Streptococcus agalactiae, a leading cause of neonatal sepsis, meningitis, and pneumonia (UniProt Q99YV1; PMID: 11544341). The enzyme specifically cleaves the human chemoattractant C5a, a potent anaphylatoxin, at its C-terminal end, thereby preventing the recruitment and activation of neutrophils to the site of infection (PMID: 21844305). By neutralizing C5a, ScpB allows the bacteria to evade the host's innate immune response and facilitate systemic dissemination (PMID: 15608301). Due to its highly conserved nature across GBS serotypes and its critical role in virulence, ScpB is a prominent target for the development of recombinant protein vaccines (PMID: 21844305). Clinical-stage candidates, such as Pfizer's GBS6, utilize ScpB or related surface proteins to induce protective antibodies that neutralize peptidase activity and enhance bacterial clearance (ClinicalTrials.gov NCT03765073).

Other names

ScpBC5a-inactivating enzymeStreptococcus agalactiae C5a peptidaseGBS C5a peptidase

Induction of neutralizing antibodies that inhibit the proteolytic activity of ScpB and promote opsonophagocytosis of the bacteria.