Leukocyte - endothelial cell interaction in infections: the role of IL1, TNF and IFN pathways

Here we comprehensively characterized the transcriptomic responses of human leukocytes (PBMC) and EC to Gram negative-bacteria, Gram positive-bacteria, and fungi by RNAseq. We showed that the common response of leukocytes to various pathogens converges on EC activation. By exposing EC to leukocyte-released mediators, with or without the presence of IL1RA and TNFa antibody, we identified specific roles for IL1 and TNFa in driving the majority of, but not exclusively, endothelial activation. Furthermore, interferon pathways are strongly induced in EC by leukocyte-released mediators, but independently from IL1 and TNFa. Our study, therefore reveals a role for IFN, together with IL1 and TNFa signaling, in mediating leukocyte-endothelial interaction in infections Overall design: We first constructed RNAseq from PBMCs from 8 individuals with 5 types of pathogens at 2 timepoints (4h and 24h). Following the transcriptome analysis in which the pathogenic impacts on PBMCs coverge on Endothelial cells, we construcuted RNAseq data on HUVECs. We investigated direct stimulation effect on HUVECs by stimulating HUVECs with IL1alpha, TNF alpha, LPS and RPMI (As a control) for 6 hours. Besides, we also obtained RNAseq from HUVECS stimulated with supernatants collected from 24h-stimulated PBMCs (with LPS, S.pneumoniae and C.albicans). Furthermore, we also add IL-1 receptor antagonist and TNF-a Ab to neutralize IL1 and TNF effect in the supernatant before exposure to HUVECs.