Navigating the murky waters of maternal fetal tolerance: Put big data at the helm

The last 20 years have seen significant progress in our understanding of the maternal T cell response to the fetus. However, major questions still remain. In this review, we discuss the contribution of Big Data approaches to our evolving understanding of maternal fetal tolerance. This includes investigations which have employed systems immunology, high dimensional mass spectrometry, whole genome transcriptomics, as well as single-cell RNA-sequencing. These studies reveal "new" mechanisms of T cell dysfunction that are conserved across immune responses and highlight the breadth and magnitude of the systemic maternal response to the fetus during pregnancy.