Cytotoxic potential of decidual NK cells and CD8+ T cells awakened by infectionsHighlights•Cytotoxicity of dNK and CD8+ dT cells is required to provide immunity to placental infections.•Regulation of cytotoxicity of dNK and CD8+ dT is essential for maternal-fetal immune tolerance.•HLA-C expression by EVT has a dual role in immune tolerance and anti-viral immunity.•Placental infections affect dNK and effector T cell activity, Treg function and EVT migration.