Stary, Georg

ABSTRACT Background and Aims Autoimmune hepatitis is an immune‐mediated liver disease characterized by chronic inflammation and progressive fibrosis. Tissue‐resident memory T cells mediate organ‐specific immunity, but their role in autoimmune hepatitis remains poorly understood. We characterized tissue‐residency‐associated T‐cell populations and their cytokine profiles, assessed associations with disease severity and determined whether these signatures were reflected in peripheral blood. Methods Paired blood and liver samples were obtained from 19 patients with autoimmune hepatitis. Comparator cohorts included 20 patients with metabolic dysfunction‐associated steatotic liver disease and 20 surgical patients providing non‐inflamed adjacent non‐tumorous liver tissue. Multiparameter flow cytometry assessed tissue‐residency markers, T‐cell differentiation and cytokine production after polyclonal stimulation. Immune phenotypes were correlated with histological and clinical parameters. Results Autoimmune hepatitis was associated with compartment‐specific remodelling of T‐cell differentiation states and intrahepatic enrichment of CD8 + T cells expressing CD69, CD103 and CXCR6 relative to paired blood and comparator liver tissues. Intrahepatic CD8 + T cells exhibited an interferon‐γ‐dominant cytokine profile, whereas CD4 + T cells showed broader interferon‐γ‐, interleukin‐17A‐ and interleukin‐4‐associated responses. Despite the enrichment of tissue‐residency‐associated CD8 + T cells, cytokine‐producing CD8 + T‐cell populations with and without a tissue‐resident memory phenotype contributed comparably to the hepatic T‐cell compartment. Tissue‐residency‐associated phenotypes correlated positively with Ishak fibrosis stage, whereas the frequency of interferon‐γ‐positive intrahepatic CD8 + T cells correlated inversely with fibrosis. Conclusions Autoimmune hepatitis was characterized by intrahepatic accumulation of phenotypically distinct and functionally active CD8 + tissue‐resident memory T cells associated with fibrosis. This immune profile was not reflected in paired blood, indicating compartmentalized hepatic immune remodelling.

Chemokine receptors and their ligands have been identified as playing an important role in the development of diffuse large B-cell lymphoma (DLBCL), follicular lymphoma, and Richter syndrome (RS). Our aim was to investigate the different expression profiles in de novo DLBCL, transformed follicular lymphoma (tFL), and RS. Here, we profiled the mRNA expression levels of 18 chemokine receptors (CCR1–CCR9, CXCR1–CXCR7, CX3CR1 and XCR1) using RQ-PCR, as well as immunohistochemistry of seven chemokine receptors (CCR1, CCR4–CCR8 and CXCR2) in RS, de novo DLBCL, and tFL biopsy-derived tissues. Tonsil-derived germinal center B-cells (GC-B) served as non-neoplastic controls. The chemokine receptor expression profiles of de novo DLBCL and tFL substantially differed from those of GC-B, with at least 5-fold higher expression of 15 out of the 18 investigated chemokine receptors (CCR1–CCR9, CXCR1, CXCR2, CXCR6, CXCR7, CX3CR1 and XCR1) in these lymphoma subtypes. Interestingly, the de novo DLBCL and tFL exhibited at least 22-fold higher expression of CCR1, CCR5, CCR8, and CXCR6 compared with RS, whereas no significant difference in chemokine receptor expression profile was detected when comparing de novo DLBCL with tFL. Furthermore, in de novo DLBCL and tFLs, a high expression of CCR7 was associated with a poor overall survival in our study cohort, as well as in an independent patient cohort. Our data indicate that the chemokine receptor expression profile of RS differs substantially from that of de novo DLBCL and tFL. Thus, these multiple dysregulated chemokine receptors could represent novel clinical markers as diagnostic and prognostic tools. Moreover, this study highlights the relevance of chemokine signaling crosstalk in the tumor microenvironment of aggressive lymphomas.

CD49a + CD16 − NK cells from the liver and contact dermatitis lesions specifically recognize antigens and contribute to adaptive immunity.