BACKGROUND AND AIMS: Acute pancreatitis (AP) is an inflammatory disease with mild to severe course that is associated with local and systemic complications and significant mortality. Uncovering inflammatory pathways that lead to progression and recovery will inform ways to monitor and/or develop effective therapies.METHODS: We performed single-cell mass cytometry (CyTOF) analysis to identify pancreatic and systemic inflammatory signals during mild (referred as AP), severe AP (SAP) and recovery using two independent experimental models and blood from AP and recurrent AP (RAP) patients. Flowcytometric validation of monocytes subsets identified by CyTOF analysis was performed independently.RESULTS: Ly6C+ inflammatory monocytes were most altered cells in the pancreas during experimental AP, recovery, and SAP. Deep profiling uncovered heterogeneity among pancreatic and blood monocytes and identified seven novel subsets during AP and recovery, and six monocyte subsets during SAP. Notably, a dynamic shift in pancreatic CD206+ macrophage population was observed during AP and recovery. Deeper profiling of the CD206+ macrophage identified seven novel subsets during AP, recovery and SAP. DE analysis of these novel monocyte and CD206+ macrophage subsets revealed significantly altered surface (CD44, CD54, CD115, CD140a, CD196, PDPN) and functional markers (IFN-gamma, IL-4, IL-22, LAP-TGF-beta, TNF-alpha, T-bet, RoRgammat) that were associated with recovery and SAP. Moreover, a targeted functional analysis further revealed distinct expression of pro- and anti-inflammatory cytokines by pancreatic CD206+ macrophage subsets as the disease either progressed or resolved. Similarly, we identified heterogeneity among circulating classical inflammatory monocytes (CD14+CD16-) and novel subsets in patients with AP and RAP.CONCLUSION: We identified several novel monocyte/macrophage subsets with unique phenotype and functional characteristics that are associated with AP, recovery, and SAP. Our findings highlight differential innate immune responses during AP progression and recovery that can be leveraged for future disease monitoring and targeting.
View details for DOI 10.1053/j.gastro.2021.08.033
View details for PubMedID 34450180