Individual liver plasmacytoid dendritic cells are capable of producing IFN? and multiple additional cytokines during chronic HCV infection.
Ontology highlight
ABSTRACT: Plasmacytoid dendritic cells (pDCs) are "natural" interferon ? (IFN?)-producing cells. Despite their importance to antiviral defense, autoimmunity, and ischemic liver graft injury, because DC subsets are rare and heterogeneous, basic questions about liver pDC function and capacity to make cytokines remain unanswered. Previous investigations failed to consistently detect IFN? mRNA in HCV-infected livers, suggesting that pDCs may be incapable of producing IFN?. We used a combination of molecular, biochemical, cytometric, and high-dimensional techniques to analyze DC frequencies/functions in liver and peripheral blood mononuclear cells (PBMCs) of hepatitis C virus (HCV)-infected patients, to examine correlations between DC function and gene expression of matched whole liver tissue and liver mononuclear cells (LMCs), and to determine if pDCs can produce multiple cytokines. T cells often produce multiple cytokines/chemokines but until recently technical limitations have precluded tests of polyfunctionality in individual pDCs. Mass cytometry (CyTOF) revealed that liver pDCs are the only LMC that produces detectable amounts of IFN? in response TLR-7/8 stimulation. Liver pDCs secreted large quantities of IFN? (~2 million molecules of IFN?/cell/hour) and produced more IFN? than PBMCs after stimulation, p = 0.0001. LMCs secreted >14-fold more IFN? than IFN? in 4 hours. Liver pDC frequency positively correlated with whole liver expression of "IFN?-response" pathway (R2 = 0.58, p = 0.007) and "monocyte surface" signature (R2 = 0.54, p = 0.01). Mass cytometry revealed that IFN?-producing pDCs were highly polyfunctional; >90% also made 2-4 additional cytokines/chemokines of our test set of 10. Liver BDCA1 DCs, but not BDCA3 DCs, were similarly polyfunctional. pDCs from a healthy liver were also polyfunctional. Our data show that liver pDCs retain the ability to make abundant IFN? during chronic HCV infection and produce many other immune modulators. Polyfunctional liver pDCs are likely to be key drivers of inflammation and immune activation during chronic HCV infection.
SUBMITTER: Doyle EH
PROVIDER: S-EPMC6687199 | biostudies-literature | 2019 Jul
REPOSITORIES: biostudies-literature
ACCESS DATA