Alpha-like protein AlphaC (AlpC) (AlpC)

Alpha-like protein AlphaC (AlpC), also known as the C-alpha protein, is a major surface-anchored protein of Streptococcus agalactiae (Group B Streptococcus, GBS) (UniProt P13515). It belongs to the Alpha-like protein family, which is characterized by a conserved N-terminal domain and a variable number of tandem repeats (PMID: 15659488). The N-terminal domain is the functional unit responsible for mediating adherence to and invasion of human epithelial cells, such as those in the vaginal and cervical tracts, by interacting with host cell receptors (PMID: 25155480). This interaction is crucial for GBS colonization of the maternal genital tract and subsequent transmission to the neonate during birth. AlpC is a significant virulence factor, contributing to the development of neonatal sepsis and meningitis (PMID: 30305354). Due to its high prevalence and role in pathogenesis, the N-terminal domain of AlpC is a primary target for protein-based vaccines, such as the GBS-NN and GBS-NN2 candidates currently in clinical development (MinervaX, 2023). These vaccines aim to elicit protective antibodies that neutralize the protein's function and promote bacterial clearance via opsonophagocytosis.

Other names

C-alpha proteinAlpha antigenSurface protein AlphaAlpCAlpha-like protein AlphaC N-terminal domain

Induction of opsonophagocytic antibodies and inhibition of bacterial adherence to host tissues.