Fig 3.

UMAP analysis of APC populations. (A) Representative plots were selected from 10 FC, 5 MIS-C, 5 RCV, 5 HC, and 3 MIS-C–like subjects. MIS-C patients demonstrate small but evident population of DC1 cells concentrated at the intermediate monocyte/nonclassic monocyte location (blue arrow). This characteristic finding in our DC patients suggests that DC1 cells have altered their phenotype to take on characteristics of these monocytes, but that they are playing a unique role via the function of CLEC9A, which is typically for antigen cross-presentation. (B, C) Two selected patients, 1 with MIS-C (B) and 1 FC (C), demonstrating expression of HLA-DR, CD86, CD115, CX3CR1, CD64, and CLEC9A. Cells in the same region demonstrate upregulation of these markers, with the exception of CLEC9A, which is only seen robustly expressed in the MIS-C patient.