The placental protein syncytin-1 impairs antiviral responses and exaggerates inflammatory responses to influenza.

ABSTRACT:

Background

Pregnancy increases susceptibility to influenza. The placenta releases an immunosuppressive endogenous retroviral protein syncytin-1. We hypothesised that exposure of peripheral monocytes (PBMCs) to syncytin-1 would impair responses to H1N1pdm09 influenza.

Methods and findings

Recombinant syncytin-1 was produced. PBMCs from non-pregnant women (n=10) were exposed to H1N1pdm09 in the presence and absence of syncytin-1 and compared to responses of PBMCs from pregnant women (n=12). PBMCs were characterised using flow cytometry, release of interferon (IFN)-?, IFN-?, IFN-?, IL-10, IL-2, IL-6 and IL-1? were measured by cytometric bead array or ELISA. Exposure of PBMCs to H1N1pdm09 resulted in the release of IFN-?, (14,787 pg/mL, 95% CI 7311-22,264 pg/mL) IFN-? (1486 pg/mL, 95% CI 756-2216 pg/mL) and IFN-? (852 pg/mL, 95% CI 193-1511 pg/mL) after 48 hours. This was significantly impaired in pregnant women (IFN-?; p<0.0001 and IFN-?; p<0.001). Furthermore, in the presence of syncytin-1, PBMCs demonstrated marked reductions in IFN-? and IFN-?, while enhanced release of IL-10 as well as IL-6 and IL-1?.

Conclusions

Our data indicates that a placental derived protein, syncytin-1 may be responsible for the heightened vulnerability of pregnant women to influenza.

SUBMITTER: Tolosa JM 

PROVIDER: S-EPMC4382184 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature