Vaccination with a latch peptide provides serotypeindependent protection against group B streptococcus infection in mice

Abstract

Streptococcus agalactiae (group B streptococcus [GBS]) is a leading cause of invasive diseases in neonates and severe infections in elderly individuals. GBS serine-rich repeat glycoprotein 1 (Srr1) acts as a critical virulence factor by facilitating GBS invasion into the central nervous system through interaction with the fbrinogen Aa chain. This study revealed that srr1 is highly conserved, with 86.7% of GBS clinical isolates expressing the protein. Vaccination of mice with different Srr1 truncated peptides revealed that only Srr1 truncates containing the latch domain protected against GBS meningiThis. Furthermore, the latch peptide alone was immunogenic and elicited protective antibodies, which efciently enhanced antibody-mediated opsonophagocytic killing of GBS by HL60 cells and provided heterogeneous protection against 4 different GBS serogroups. Taken together, these fndings indicated that the latch domain of Srr1 may constitute an effective peptide vaccine candidate for GBS. © The Author(s) 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved.