CRIg-expressing peritoneal macrophages are associated with disease severity in patients with cirrhosis and ascites
Katharine M. Irvine, … , Matthew J. Sweet, Elizabeth E. Powell
Katharine M. Irvine, … , Matthew J. Sweet, Elizabeth E. Powell
Published June 2, 2016
Citation Information: JCI Insight. 2016;1(8):e86914. https://doi.org/10.1172/jci.insight.86914.
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Categories: Research Article Hepatology Inflammation

CRIg-expressing peritoneal macrophages are associated with disease severity in patients with cirrhosis and ascites

Abstract

Infections are an important cause of morbidity and mortality in patients with decompensated cirrhosis and ascites. Hypothesizing that innate immune dysfunction contributes to susceptibility to infection, we assessed ascitic fluid macrophage phenotype and function. The expression of complement receptor of the immunoglobulin superfamily (CRIg) and CCR2 defined two phenotypically and functionally distinct peritoneal macrophage subpopulations. The proportion of CRIghi macrophages differed between patients and in the same patient over time, and a high proportion of CRIghi macrophages was associated with reduced disease severity (model for end-stage liver disease) score. As compared with CRIglo macrophages, CRIghi macrophages were highly phagocytic and displayed enhanced antimicrobial effector activity. Transcriptional profiling by RNA sequencing and comparison with human macrophage and murine peritoneal macrophage expression signatures highlighted similarities among CRIghi cells, human macrophages, and mouse F4/80hi resident peritoneal macrophages and among CRIglo macrophages, human monocytes, and mouse F4/80lo monocyte-derived peritoneal macrophages. These data suggest that CRIghi and CRIglo macrophages may represent a tissue-resident population and a monocyte-derived population, respectively. In conclusion, ascites fluid macrophage subset distribution and phagocytic capacity is highly variable among patients with chronic liver disease. Regulating the numbers and/or functions of these macrophage populations could provide therapeutic opportunities in cirrhotic patients.

Authors

Katharine M. Irvine, Xuan Banh, Victoria L. Gadd, Kyle K. Wojcik, Juliana K. Ariffin, Sara Jose, Samuel Lukowski, Gregory J. Baillie, Matthew J. Sweet, Elizabeth E. Powell

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Figure 3

Increased microbial phagocytic capacity in CRIg+ macrophages.

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Increased microbial phagocytic capacity in CRIg+ macrophages. (A) Repres...
(A) Representative histograms showing CRIghi and CRIglo fluorescence in the absence and presence of pHRodo E. coli bioparticles. (B) Proportion of CRIghi and CRIglo macrophages phagocytosing E. coli bioparticles and (C) change in median fluorescence intensity (MFI) with uptake (n = 22, Mann-Whitney test). (D) E. coli phagocytosis (CFU/ml 1 hour after infection, relative to CRIghi macrophages) (n = 3, 1-sample t test) and (E) killing capacity (proportion of phagocytosed E. coli [1 hour] surviving at 4 hours) in CRIghi CRIglo and human monocyte-derived macrophages (HMDM) (n = 3, Mann-Whitney Test). Dot plot data in B–E represent mean ± SEM. (F) Correlation between ascites fluid macrophage phagocytic capacity and MELD score (n = 15, spearman r = 0.65, P = 0.009). (G) Correlation between increased CRIg expression and phagocytic capacity in the presence of autologous ascites fluid (fold change compared with incubation in culture medium) (n = 12, spearman r = 0.87, P = 0.0002).