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Biology subjects

Abdullah, Z.

Publications and source records attributed to Abdullah, Z..

2 recordsLinked to original sources

Suppression of systemic T cell immunity to viral infection during liver injury is prevented by inhibition of interferon and IL-10 signaling

Patients with liver injury such as cirrhosis are at increased risk of intractable viral infections and are hyporesponsive to vaccination. Here, we report that liver injury leads to inhibition of systemic T cell immunity (LIST), which abrogated anti-viral immunity and caused persistent infection in preclinical liver injury models. Enhanced gut microbial-translocation but not dysbiosis induced tonic type-I-interferon (IFN) signaling in hepatic myeloid cells, which was responsible for their excessive production of IL-10 after viral infection. Antibiotic treatment reducing intestinal microbial burden or inhibition of IFN- and IL-10-signaling all restored anti-viral immunity without immune pathology. Importantly, inhibition of IL-10 restored virus-specific immune responses to vaccination in cirrhotic patients. Thus, LIST results from sequential events involving intestinal microbial translocation, hepatic myeloid cell-derived IFN-/IL-10 expression, and finally inhibitory IL-10 receptor-signaling in T cells, of which IL-10R-signaling may serve as target to reconstitute anti-viral T cell immunity in cirrhotic patients.

immunology↗

Intercellular crosstalk regulating ARRB2/RARRES1 is involved in transition from fibrosis to cancer

Progressive fibrogenesis in chronic liver injury is often associated with cancer development. Beta-arrestin-2 (ARRB2) is a regulator of the profibrotic Angiotensin II type 1 receptor (AGTR1). The role of ARRB2 in liver fibrosis and in the transition from fibrosis to cancer is not fully understood and was investigated in this study. This study demonstrates that upregulation of the retinoic acid receptor responder 1 (RARRES1) in HSC mediated by ARRB2 leads to fibrosis. This process is driven by exosomal ARRB2 transfer to HSC, major fibrosis contributors, from injured hepatocytes, which highly express ARRB2. By contrast, downregulation of RARRES1 in hepatocytes induces malignant transformation and hepatocellular carcinoma (HCC) development. Consequently, Arrb2-deficient mice show higher number and size of liver tumors than wild-type mice in a hepatocellular carcinoma model with fibrosis. The identified relationship between ARRB2 and RARRES1 was observed in at least two species, including human cells and tissues in fibrosis and HCC and has a predictive value for survival in cancer patients. This study describes the discovery of a novel molecular pathway mediating the transition from fibrosis to cancer offering potential diagnostics and therapeutics.

molecular biology↗