Immunological observations and transcriptomic analysis of trimester-specific full-term placentas from three Zika virus-infected women.

Objectives: Effects of Zika virus (ZIKV) infection on placental development during pregnancy are unclear.

Methods: Full-term placentas from three women, each infected with ZIKV during specific pregnancy trimesters, were harvested for anatomic, immunologic and transcriptomic analysis.

Results: In this study, each woman exhibited a unique immune response with raised IL-1RA, IP-10, EGF and RANTES expression and neutrophil numbers during the acute infection phase. Although ZIKV NS3 antigens co-localised to placental Hofbauer cells, the placentas showed no anatomic defects. Transcriptomic analysis of samples from the placentas revealed that infection during trimester 1 caused a disparate cellular response centred on differential eIF2 signalling, mitochondrial dysfunction and oxidative phosphorylation. Despite these, the babies were delivered without any congenital anomalies.

Conclusion: These findings should translate to improve clinical prenatal screening procedures for virus-infected pregnant patients.