Antonios Katsounas

Prof. Dr. Antonios Katsounas

orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2010 in Journal of Interferon & Cytokine Research
Verified
Journal Article
Closed access
AFAstrid C. Frank
Astrid C. Frank
XZXiaozhen Zhang
Xiaozhen Zhang
AKAntonios Katsounas
Antonios Katsounas
JBJennifer P. Bharucha
Jennifer P. Bharucha
SKShyamasundaran Kottilil
Shyamasundaran Kottilil
Tomozumi ImamichiTomozumi Imamichi
Tomozumi Imamichi
Interleukin (IL)-27 is a member of IL-12 family cytokine. We have previously reported that IL-27 inhibits human immunodeficiency virus type-1 (HIV-1) replication in CD4 + T cells and monocyte-derived macrophages, even though IL-12 enhances HIV-1 replication in primary CD4 + T cells. Further study demonstrates that IL-27 induces antiviral genes including RNA-dependent protein kinase, oligoadenylate synthetase, and myxovirus protein in the same manner as interferon (IFN)-α. Neutralization assay using anti-IFN antibodies, real-time RT-PCR, and enzyme-linked immunosorbent assay demonstrated that IL-27 induces the antiviral genes without the induction of IFNs. IFN-α has been administered to hepatitis C virus (HCV)-infected patients as well as HCV/HIV-1 co-infected patients. Despite the improved immunotherapy, some patients are still failed to respond to the treatment. Since IL-27 induces IFN-α-like responses including the induction of antiviral genes, it was speculated that IL-27 may impact the replication of HCV. In this study, we evaluated the role of IL-27 on HCV replication using Huh7.5, an HCV permissive cell line. IL-27 induces STAT-1 and −3 in the cell line, and dose-dependently inhibited HCV. These data suggest that IL-27 may play a role in the development of a novel immunotherapeutic strategy for HCV and HCV/HIV co-infection.

13 February 2012 in Hepatology
Verified
Journal Article
Open access
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SNSusanna Naggie
Susanna Naggie
AOAnu Osinusi
Anu Osinusi
AKAntonios Katsounas
Antonios Katsounas
RLRichard Lempicki
Richard Lempicki
EHEva Herrmann
Eva Herrmann
SKShyam Kottilil
Shyam Kottilil
Recent studies have shown that a single-nucleotide polymorphism upstream of the interleukin-28B ( IL28B ) gene plays a major role in predicting therapeutic response in hepatitis C virus (HCV)-infected patients treated with pegylated interferon (PEG-IFN)/ribavirin. We sought to investigate the mechanism of the IL28B polymorphism, specifically as it relates to early HCV viral kinetics, IFN pharmacokinetics, IFN pharmacodynamics, and gene expression profiles. Two prospective cohorts (human immunodeficiency virus [HIV]/HCV-coinfected and HCV-monoinfected) completing treatment with IFN/ribavirin were enrolled. Patients were genotyped at the polymorphic site rs12979860. In the HIV/HCV cohort, frequent serum sampling was completed for HCV RNA and IFN levels. DNA microarray of peripheral blood mononuclear cells and individual expression of IFN-stimulated genes (ISGs) were quantified on IFN therapy. The IL28B -favorable (CC) genotype was associated with improved therapeutic response compared with unfavorable (CT or TT) genotypes. Patients with a favorable genotype had greater first- and second-phase viral kinetics ( P = 0.004 and P = 0.036, respectively), IFN maximum antiviral efficiency ( P = 0.007) and infected cell death loss ( P = 0.009) compared with unfavorable genotypes. Functional annotation analysis of DNA microarray data was consistent with depressed innate immune function, particularly of natural killer cells, from patients with unfavorable genotypes ( P <0.004). Induction of innate immunity genes was also lower in unfavorable genotypes. ISG expression at baseline and induction with IFN was independent of IL28B genotype. Conclusion: Carriers of the IL28B -favorable genotype were more likely to have superior innate immune response to IFN therapy compared with unfavorable genotypes, suggesting that the unfavorable genotype has aberrant baseline induction of innate immune response pathways resulting in impaired virologic response. IL28B genotype is associated with more rapid viral kinetics and improved treatment response outcomes independent of ISG expression. (HEPATOLOGY 2012)

25 February 2019 in Mediators of Inflammation
Verified
Journal Article
Open access
PDF file
BWBenjamin Wilde
Benjamin Wilde
AKAntonios Katsounas
Antonios Katsounas
Liver cirrhosis yearly causes 1.2 million deaths worldwide, ranking as the 10th leading cause of death in the most developed countries. High susceptibility to infections along with a significant risk for infection-related mortality justifies the description of liver cirrhosis as the world’s most common immunodeficiency syndrome. Liver cirrhosis is an end-stage organic disease hallmarked by a multifaceted immune dysfunction due to deterioration of antimicrobial recognition and elimination mechanisms in macrophages along with an impaired antigen presentation ability in circulating monocytes. Bacterial translocation supports—and is supported by—uncontrolled activation of immune cell responses and/or loss of toll-like receptor (TLR) tolerance, which can turn exaggerated inflammatory responses to systemic inflammation. Lipopolysaccharide (LPS) or endotoxin boosts systemic inflammatory activity through activation of TLR-2- and TLR-4-dependent pathways and facilitate a massive production of cytokines. This, in turn, results into elevated secretion of reactive oxygen species (ROS), which further enhances intestinal hyperpermeability and thus sustains a vicious circle of events widely known as “leaky gut.” Albumin can be of particular benefit in cirrhotic patients with spontaneous bacterial peritonitis and/or hepatorenal syndrome type of acute kidney injury (HRS-AKI) due to anti-inflammatory and antioxidative stress as well as volume-expanding properties and endothelial-stabilizing attributes. However, presence of autoantibodies against albumin in patients with liver cirrhosis has been described. Although previous research suggested that these antibodies should be regarded as naturally occurring antibodies (NOA), the origin of the antialbumin immune response is obscure. High occurrence of NAO/albumin complexes in patients with liver disease might reflect a limited clearance capacity due to bypassing portal circulation. Moreover, high burden of oxidized albumin is associated with less favorable outcome in patients with liver cirrhosis. To date, there is no data available as to whether oxidized forms of albumin result in neoepitopes recognized by the immune system. Nevertheless, it is reasonable to hypothesize that these alterations may have the potential to induce antialbumin immune responses and thus favor systemic inflammation.

2 October 2016 in Liver International
Verified
Journal Article
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SBSotiria Bedreli
Sotiria Bedreli
JSJan-Peter Sowa
Jan-Peter Sowa
SMSaraa Malek
Saraa Malek
SBSandra Blomeyer
Sandra Blomeyer
AKAntonios Katsounas
Antonios Katsounas
ACAli Canbay
Ali Canbay

7 November 2011 in International Reviews of Immunology
Verified
Journal Article
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AKAntonios Katsounas
Antonios Katsounas
JSJoerg F. Schlaak
Joerg F. Schlaak
RLRichard A. Lempicki
Richard A. Lempicki
C-C motif ligand 5 (CCL5) facilitates induction of chemotaxis in immune cells and activation of hepatic stellate cells (HSC) at sites of liver inflammation during chronic hepatitis C virus (HCV) infection. Importantly, CCL5 participates in the establishment of T-helper 1 responses crucial in controlling liver disease and HCV infection outcome and demonstrates distinct gene expression patterns between the blood and the liver, stressing the importance of immunoregulatory networks differentially functioning between these compartments. This review illustrates the significance of CCL5-dependent pathways in HCV-related immunopathogenesis by elaborating on biological mechanisms interconnecting peripheral and tissue immunology, liver pathology, HSC activation, and interferon-α immunotherapy.

7 December 2009 in Cancer Investigation
Verified
Journal Article
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CFChristian Dominik Fingas
Christian Dominik Fingas
AKAntonios Katsounas
Antonios Katsounas
AKAlisan Kahraman
Alisan Kahraman
WSWinfried Siffert
Winfried Siffert
CJChristoph Jochum
Christoph Jochum
ACAli Canbay
Ali Canbay
Background/Aims: Cholangiocellular carcinoma (CCA) has a devastating prognosis and markers enabling a precise prediction of the clinical outcome have long remained scarce. Recently, it has been demonstrated that genotype distribution of several single-nucleotide polymorphisms (SNPs) in genes that modulate G protein-signal transduction and apoptosis can serve as helpful predictive parameters in various carcinomas. We here aimed at extending the panel of SNPs suitable for predicting the outcome of CCA. Methodology: Forty Caucasian patients with extrahepatic CCA and 40 age- and sex-matched healthy white Caucasians were genotyped to elucidate putative associations between clinical outcome and genotypes of the three following SNPs: G protein β 3 (GNB3) 825C>T, B-cell-lymphoma-2 (Bcl-2) -938C>A, and myeloid cell leukemia-1 (Mcl-1) -386C>G. Results: Patients homozygous for the C allele of the GNB3 825C>T polymorphism exhibited a significant prolonged overall survival compared with patients displaying the CT or TT genotype (median survival [months]: 31 vs. 13 vs. 7; p < .05) and also showed lower bilirubin serum levels. Additionally, the CC genotype of the BCL2-938C>A polymorphism was associated with higher GLDH serum activities (U/l; 29.8 ± 7.1 vs. 11.4 ± 4.3 vs. 5.6 ± 1.7 comparing CC vs. CA vs. AA; p < .05). Genotype distributions for all SNPs were not significantly different in patients vs. controls. Conclusions: GNB3 825C>T SNP may be a novel independent prognostic marker for patients suffering from extrahepatic CCA with the CC genotype to be associated with a favorable clinical outcome. Further prospective studies are needed to confirm these results and reveal additional functional SNP effects.