Single-cell RNA-sequencing highlights a curtailed NK cell function in post COVID-19 pregnant women

During gestation the immune system undergoes dramatic remodelling to accommodate the semi allogenic fetus but also to protect the mother from infections. We investigated how SARS-CoV-2 modifes the immune landscape during infection and in recovered pregnant women. Using two independent global cohorts, we identified that NK cells are diminished during active infection and in recovered pregnant women. Further, our single-cell RNA sequencing data revealed that infection with SARS-CoV-2 rewired the gene expression profile of monocytes, CD4⁺ effector cells and antibody producing B cells in convalescent pregnant women. Several gene pathways associated with cytotoxic function, interferon signalling type I & II, and pro- and anti-inflammatory functions in natural killer and CD8⁺ cytotoxic T cells were reduced in recovered pregnant patients compared with healthy pregnancies. Further, cytotoxic function proteins perforin and granzyme B secreting NK cells were diminished in convalescent patients. Overall, our study highlights that SARS-CoV-2 infection deranged the adaptive immune response in pregnant women.