Monocyte Heterogeneity and Distinct Monocyte Subsets in Kawasaki Disease Revealed by scRNA-seq
Kawasaki disease (KD) is characterized by a disorder of immune response, and its etiology remains unknown. Monocyte is an important member of body's innate immune system, however its role in KD is still elusive due to its ambiguous heterogeneity and complex functions. Here, scRNA-seq was performed to reveal monocytes heterogeneity in healthy and KD infants. Circulating monocytes were separated from peripheral blood and scRNA-seq was used to transcriptionally profile the monocytes in both healthy and KD infants. Four monocyte subsets are identified in infants, in which three clusters are mainly CD14+CD16- monocytes and one cluster is mainly CD14-CD16+ monocytes. The four monocyte subsets possess different biological functions and represent a relatively linear differentiation. CD14+ monocyte subsets in KD are distinct from that of healthy infants, including one subset expressing FOLR3, S100A12 and IL1R2 and the other expressing MT-TN specifically. Moreover, the CD14+ monocyte subsets in KD are poorly differentiated, and their functions mainly involve neutrophil activation. In conclusion, a relatively comprehensive map of circulating monocyte subsets was plotted for the first time in healthy infants. CD14+ monocyte subsets that are distinct from healthy infants were revealed in KD, which may serve as a target for KD treatment in the future. Overall design: scRNA-Seq of enriched monocytes in 2 healthy infants and 2 KD infants