ORCID Profile
0000-0001-9325-8227
Current Organisation
University Medical Center Hamburg-Eppendorf
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Publisher: Springer Science and Business Media LLC
Date: 22-02-2023
DOI: 10.1038/S41586-023-05728-Y
Abstract: Pancreatic ductal adenocarcinoma (PDAC) is expected to be the second most deadly cancer by 2040, owing to the high incidence of metastatic disease and limited responses to treatment 1,2 . Less than half of all patients respond to the primary treatment for PDAC, chemotherapy 3,4 , and genetic alterations alone cannot explain this 5 . Diet is an environmental factor that can influence the response to therapies, but its role in PDAC is unclear. Here, using shotgun metagenomic sequencing and metabolomic screening, we show that the microbiota-derived tryptophan metabolite indole-3-acetic acid (3-IAA) is enriched in patients who respond to treatment. Faecal microbiota transplantation, short-term dietary manipulation of tryptophan and oral 3-IAA administration increase the efficacy of chemotherapy in humanized gnotobiotic mouse models of PDAC. Using a combination of loss- and gain-of-function experiments, we show that the efficacy of 3-IAA and chemotherapy is licensed by neutrophil-derived myeloperoxidase. Myeloperoxidase oxidizes 3-IAA, which in combination with chemotherapy induces a downregulation of the reactive oxygen species (ROS)-degrading enzymes glutathione peroxidase 3 and glutathione peroxidase 7. All of this results in the accumulation of ROS and the downregulation of autophagy in cancer cells, which compromises their metabolic fitness and, ultimately, their proliferation. In humans, we observed a significant correlation between the levels of 3-IAA and the efficacy of therapy in two independent PDAC cohorts. In summary, we identify a microbiota-derived metabolite that has clinical implications in the treatment of PDAC, and provide a motivation for considering nutritional interventions during the treatment of patients with cancer.
Publisher: Wiley
Date: 20-07-2021
DOI: 10.1111/TID.13685
Publisher: American Society for Clinical Investigation
Date: 20-09-2018
Publisher: Elsevier BV
Date: 02-2022
Publisher: American Society for Clinical Investigation
Date: 10-01-2023
Publisher: American Association for the Advancement of Science (AAAS)
Date: 12-02-2021
DOI: 10.1126/SCIIMMUNOL.ABF6692
Abstract: Tissue-resident memory-like T H 17 cells are clonally expanded in bronchoalveolar lavage fluid of patients with severe COVID-19.
Publisher: Elsevier BV
Date: 08-2021
Publisher: American Chemical Society (ACS)
Date: 02-03-2021
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.JHEP.2019.05.023
Abstract: Primary sclerosing cholangitis (PSC) is an idiopathic, chronic cholestatic liver disorder characterized by biliary inflammation and fibrosis. Increased numbers of intrahepatic interferon-γ- (IFNγ) producing lymphocytes have been documented in patients with PSC, yet their functional role remains to be determined. Liver tissue s les were collected from patients with PSC. The contribution of lymphocytes to liver pathology was assessed in Mdr2 Patients with PSC showed increased IFNγ serum levels and elevated numbers of hepatic CD56 IFNγ changed the phenotype of hepatic CD8 Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by biliary inflammation and fibrosis, whose current medical treatment is hardly effective. We observed an increased interferon (IFN)-γ response in patients with PSC and in a mouse model of sclerosing cholangitis. IFNγ changed the phenotype of hepatic CD8
Publisher: Springer Science and Business Media LLC
Date: 28-03-2022
DOI: 10.1038/S42255-022-00552-6
Abstract: Extrapulmonary manifestations of COVID-19 have gained attention due to their links to clinical outcomes and their potential long-term sequelae 1 . Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) displays tropism towards several organs, including the heart and kidney. Whether it also directly affects the liver has been debated 2,3 . Here we provide clinical, histopathological, molecular and bioinformatic evidence for the hepatic tropism of SARS-CoV-2. We find that liver injury, indicated by a high frequency of abnormal liver function tests, is a common clinical feature of COVID-19 in two independent cohorts of patients with COVID-19 requiring hospitalization. Using autopsy s les obtained from a third patient cohort, we provide multiple levels of evidence for SARS-CoV-2 liver tropism, including viral RNA detection in 69% of autopsy liver specimens, and successful isolation of infectious SARS-CoV-2 from liver tissue postmortem. Furthermore, we identify transcription-, proteomic- and transcription factor-based activity profiles in hepatic autopsy s les, revealing similarities to the signatures associated with multiple other viral infections of the human liver. Together, we provide a comprehensive multimodal analysis of SARS-CoV-2 liver tropism, which increases our understanding of the molecular consequences of severe COVID-19 and could be useful for the identification of organ-specific pharmacological targets.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 14-08-2020
DOI: 10.1126/SCIIMMUNOL.ABA4163
Abstract: CD4 + T RM 17 cells become activated by inflammatory cytokines to produce IL-17A and thereby promote autoimmunity.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2020
DOI: 10.1002/HEP.31140
Abstract: T cells from patients with primary sclerosing cholangitis (PSC) show a prominent interleukin (IL)‐17 response upon stimulation with bacteria or fungi, yet the reasons for this dominant T‐helper 17 (Th17) response in PSC are not clear. Here, we analyzed the potential role of monocytes in microbial recognition and in skewing the T‐cell response toward Th17. Monocytes and T cells from blood and livers of PSC patients and controls were analyzed ex vivo and in vitro using transwell experiments with cholangiocytes. Cytokine production was measured using flow cytometry, enzyme‐linked immunosorbent assay, RNA in situ hybridization, and quantitative real‐time PCR. Genetic polymorphisms were obtained from ImmunoChip analysis. Following e x vivo stimulation with phorbol myristate acetate/ionomycin, PSC patients showed significantly increased numbers of IL‐17A–producing peripheral blood CD4 + T cells compared to PBC patients and healthy controls, indicating increased Th17 differentiation in vivo . Upon stimulation with microbes, monocytes from PSC patients produced significantly more IL‐1β and IL‐6, cytokines known to drive Th17 cell differentiation. Moreover, microbe‐activated monocytes induced the secretion of Th17 and monocyte‐recruiting chemokines chemokine (C‐C motif) ligand (CCL)‐20 and CCL‐2 in human primary cholangiocytes. In livers of patients with PSC cirrhosis, CD14 hi CD16 int and CD14 lo CD16 hi monocytes/macrophages were increased compared to alcoholic cirrhosis, and monocytes were found to be located around bile ducts. PSC patients show increased Th17 differentiation already in vivo . Microbe‐stimulated monocytes drive Th17 differentiation in vitro and induce cholangiocytes to produce chemokines mediating recruitment of Th17 cells and more monocytes into portal tracts. Taken together, these results point to a pathogenic role of monocytes in patients with PSC.
Publisher: Wiley
Date: 12-2021
Abstract: The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical s les with ex les of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer‐reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state‐of‐the‐art handbook for basic and clinical researchers.
Publisher: Wiley
Date: 2022
DOI: 10.1002/CTI2.1410
Abstract: Potential differences in the breadth, distribution and magnitude of CD4 + T‐cell responses directed against the SARS‐CoV‐2 spike glycoprotein between vaccinees, COVID‐19 patients and subjects who experienced both ways of immunisation have not been comprehensively compared on a peptide level. Following virus‐specific in vitro cultivation, we determined the T‐cell responses directed against 253 in idual overlapping 15‐mer peptides covering the entire SARS‐CoV‐2 spike glycoprotein using IFN‐γ ELISpot and intracellular cytokine staining. In vitro HLA binding was determined for selected peptides. We mapped 955 single peptide‐specific CD4 + T‐cell responses in a cohort of COVID‐19 patients ( n = 8), uninfected vaccinees ( n = 16) and in iduals who experienced both infection and vaccination ( n = 11). Patients and vaccinees (two‐time and three‐time vaccinees alike) had a comparable number of CD4 + T‐cell responses (median 26 vs. 29, P = 0.7289). Most of these specificities were conserved in B.1.1.529 and the BA.4 and BA.5 sublineages. The highest magnitude of these in vitro IFN‐γ CD4 + T‐cell responses was observed in COVID‐19 patients (median 0.35%), and three‐time vaccinees showed a higher magnitude than two‐time vaccinees (median 0.091% vs. 0.175%, P 0.0001). Twelve peptide specificities were each detected in at least 40% of subjects. In vitro HLA binding showed promiscuous presentation by DRB1 molecules for several peptides. Both SARS‐CoV‐2 infection and vaccination prime broadly directed T‐cell responses directed against the SARS‐CoV‐2 spike glycoprotein. This comprehensive high‐resolution analysis of spike peptide specificities will be a useful resource for further investigation of spike‐specific T‐cell responses.
No related grants have been discovered for Samuel Huber.