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bioRxiv · 10.1101/2024.03.29.587228

Targeting the expansion of myeloid-derived suppressor cells in liver cirrhosis

Abstract

Background and aimsPreviously, we identified immune-suppressive circulating monocytic myeloid-derived suppressor cells (M-MDSC) in patients with cirrhosis and liver failure, which increased with disease severity and were associated with infections and mortality. Impaired immune responses and M-MDSC expansion were reversed by ex vivo polyinosinic:polycytidylic acid (poly(I:C)) treatment. Here, we aimed to investigate hepatic MDSC subsets in liver biopsies of cirrhotic patients and identify MDSC subsets in murine models to assess the safety and efficacy of poly(I:C) in vivo. Methods22 cirrhotic patients and 4 controls were clinically characterised. MDSC were identified in liver biopsies (immunofluorescence) and in the circulation (flow cytometry). M- MDSC phenotype and function following poly(I:C) stimulation were assessed ex vivo. Carbon tetrachloride-based murine models of liver fibrosis were used. Poly(I:C) was administered therapeutically. MDSC biology was investigated with flow cytometry, immunofluorescence and T-cell proliferation assay. Hepatic histopathology, transcriptomics (BulkRNAseq) and serum markers were assessed. ResultsBesides circulating M-MDSC, hepatic CD14+CD84+M-MDSC and CD15+CD84+ polymorphonuclear-MDSC expanded in cirrhotic patients and indicated disease severity, infections and poor survival. Poly(I:C) treatment reversed phenotype and function of circulating M-MDSC ex vivo. Circulating and hepatic MDSC expanded in our murine models of liver fibrosis and suppressed T-cell proliferation. Lipopolysaccharide and E.coli challenge exacerbated hepatic MDSC and fibrosis compared to CCl4 controls. Poly(I:C) therapy reduced MDSC expansion in fibrotic mice with bacterial infection and CCl4-induced fibrosis. ConclusionHepatic MDSC expanded in cirrhotic patients and were linked with disease severity and poor prognosis. Poly(I:C) reversed frequency and function of M-MDSC ex vivo. Poly(I:C) therapy reversed MDSC expansion and fibrosis in a murine model of liver fibrosis with infection. Thus, we highlighted poly(I:C) as a potential immunotherapy for the treatment of immuneparesis in cirrhosis.

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Flint, E. E., Ercan, C., Mitchell, E., Pop, O. T., Geng, A., Jorzik, P., Possamai, L. A., Brenig, R. G., Morel, S., Sieber, P., Singanayagam, A., Matter, M. S., Semela, D., Heim, M. H. E., Demougin, P., Roux, J., Terracciano, L. M., Triantafyllou, E., Bernsmeier, C.. 2024-04-01. Targeting the expansion of myeloid-derived suppressor cells in liver cirrhosis. https://doi.org/10.1101/2024.03.29.587228

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