Siglec-5 and Siglec-14 are polymorphic paired receptors that modulate neutrophil and amnion signaling responses to group B Streptococcus.

ABSTRACT: Group B Streptococcus (GBS) causes invasive infections in human newborns. We recently showed that the GBS β-protein attenuates innate immune responses by binding to sialic acid-binding immunoglobulin-like lectin 5 (Siglec-5), an inhibitory receptor on phagocytes. Interestingly, neutrophils and monocytes also express Siglec-14, which has a ligand-binding domain almost identical to Siglec-5 but signals via an activating motif, raising the possibility that these are paired Siglec receptors that balance immune responses to pathogens. Here we show that β-protein-expressing GBS binds to both Siglec-5 and Siglec-14 on neutrophils and that the latter engagement counteracts pathogen-induced host immune suppression by activating p38 mitogen-activated protein kinase (MAPK) and AKT signaling pathways.

SUBMITTER: Ali SR 

PROVIDER: S-EPMC4042635 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature