In summary, we described the charac

In summary, we described the characteristic Tim-3 and PD-1 expression patterns on dCD8+ T cells in both normal pregnancy and miscarriage, and elucidated their important roles in regulating dCD8+ T-cell function and maternal–fetal tolerance. Our data also demonstrate that, apart from Th2 bias by CD4+ T cells, Tim-3+PD-1+CD8+ T cells could also have an active role in shaping Th2 bias and regulating maternal–fetal tolerance. Moreover, approaches to promote the Tim-3/PD-1 pathway, such as treatment with agonistic Tim-3/PD-1 antibodies or galectin-9/PD-L1, may represent novel therapeutic strategies to prevent pregnancy loss. Our future studies will investigate whether the population of Tim-3+PD-1+ CD8+ T cell is the key mediator of tolerance in normal pregnancy by using conditioned knockout mouse models.