Single-cell analysis of human thymus and peripheral blood unveils the dynamics of T-cell development and aging.

Age-related thymic involution is the hallmark of immune aging, leading to susceptibility to cancers and emerging pathogens such as SARS-Cov2 in the elderly. However, the precise mechanisms underlying the thymic involution and the effect on compromised peripheral T-cell function is unknown. Here by scRNA-seq and TCR-seq, we captured and analyzed cells in the thymus and peripheral blood from the young and elderly. Collectively, our data constitute the first detailed single-cell analysis of ageing-related human thymic involution and T-cell homeostasis in peripheral, providing the insights into human immune aging and potential strategies to rejuvenate the involuted thymus and compromised T-cell immunity. Human thymus and peripheral blood samples in different age groups were obtained from patients undergoing cardiac surgery following protocol approved by the Ethics Committee of the West China Hospital, Sichuan University. Fresh peripheral blood from supercentenarians was also obtained following the protocol approved by the Ethics Committee of the West China Hospital Sichuan University. Informed consent was obtained from all donors.