Background: Kawasaki disease (KD) is characterized by a disorder of immune response, and its etiology remains unknown . Monocyte is an important member of the body's innate immune system; however its role in KD is still elusive due to its ambiguous heterogeneity and complex functions . We aim to comprehensively delineate monocyte heterogeneity in healthy and KD infants and to reveal the underlying mechanism for KD .
Methods: Peripheral monocytes were enriched from peripheral blood samples of two healthy infants and two KD infants . scRNA-seq was performed to acquire the transcriptomic atlas of monocytes . Bio-information analysis was utilized to identify monocyte subsets and explore their functions and differentiation states . SELL+CD14+CD16- monocytes were validated using flow cytometry .
Results: Three monocyte subsets were identified in healthy infants, including CD14+CD16- monocytes, CD14+CD16+ monocytes, and CD14 Low CD16+ monocytes . Cell trajectory analysis revealed that the three monocyte subsets represent a linear differentiation, and possess different biological functions . Furthermore, SELL+CD14+CD16- monocytes, which were poorly differentiated and relating to neutrophil activation, were found to be expanded in KD . Conclusion: Our findings provide a valuable resource for deciphering the monocyte heterogeneity in healthy infants and uncover the altered monocyte subsets in KD patients, suggesting potential biomarkers for KD diagnosis and treatment.
Index: Kawasaki disease, monocyte subsets, scRNA-seq