BaCKgRoUND aND aIMS: Stratified therapy has entered clinical practice in primary biliary cholangitis (PBC), with routine use of second-line therapy in nonresponders to first-line therapy with ursodeoxycholic acid (UDCA). The mechanism for nonresponse to UDCA remains, however, unclear and we lack mechanistic serum markers. The UK-PBC study was established to explore the biological basis of UDCA nonresponse in PBC and identify markers to enhance treatment.appRoaCH aND ReSUltS: Discovery serum proteomics (Olink) with targeted multiplex validation were carried out in 526 subjects from the UK-PBC cohort and 97 healthy controls. In the discovery phase, untreated PBC patients (n = 68) exhibited an inflammatory proteome that is typically reduced in scale, but not resolved, with UDCA therapy (n = 416 treated patients). Nineteen proteins remained at a significant expression level (defined using stringent criteria) in UDCA-treated patients, six of them representing a tightly linked profile of chemokines (including CCL20, known to be released by biliary epithelial cells (BECs) undergoing senescence in PBC). All showed significant differential expression between UDCA responders and nonresponders in both the discovery and validation cohorts. A linear discriminant analysis, using serum levels of C-X-C motif chemokine ligand 11 and C-C motif chemokine ligand 20 as markers of responder status, indicated a high level of discrimination with an AUC of 0.91 (CI, 0.83-0.91).CoNClUSIoNS: UDCA under-response in PBC is characterized by elevation of serum chemokines potentially related to cellular senescence and was previously shown to be released by BECs in PBC, suggesting a potential role in the pathogenesis of high-risk disease. These also have potential for development as biomarkers for identification of high-risk disease, and their clinical utility as biomarkers should be evaluated further in prospective studies. (Hepatology 2021;74:3269-3283). P rimary biliary cholangitis (PBC) is a chronic cholestatic liver disease with a significant inflammatory/immune component. (1) The condition is characterized by damage to, and eventual destruction of, the small intrahepatic bile ducts. Duct

Objective As well as being an established oncoprotein and therapeutic target in cancer, proviral integration site for Moloney murine leukemia virus 1 (Pim‐1) is implicated in human autoimmunity. This study was undertaken to investigate Pim‐1 and its family members as potential therapeutic targets in early rheumatoid arthritis (RA). Methods A flow cytometry assay for PIM1 transcript measurement in peripheral blood mononuclear cells from patients with early arthritis was validated and applied as a biomarker of Pim‐1 activity at the cellular level. Synovial protein expression was similarly determined by multiplex immunofluorescence in tissue samples from untreated RA patients and non‐RA disease controls. Functional consequences of Pim kinase family manipulation in freshly isolated CD4+ T cells from these individuals were ascertained, along with the impact of Pim inhibition on mice with collagen‐induced arthritis (CIA). Results The percentage of circulating CD4+ T cells positive for PIM1 transcript by flow cytometry proved a faithful surrogate for gene expression and was significantly higher in patients with early RA than in those with other diseases. Pim‐1 protein levels were similarly up‐regulated in synovial CD4+ T cells from patients with early RA. Ex vivo, exposure of T cell receptor–stimulated early RA CD4+ T cells to Pim kinase inhibitors restrained their activation and proliferative capacity. Diminished production of proinflammatory cytokines (interferon‐γ and interleukin‐17) and an expanded CD25highFoxP3+ Treg cell fraction were also observed in exposed versus unexposed cells. Finally, administration of Pim inhibitors robustly limited arthritis progression and cartilage destruction in CIA. Conclusion Our findings indicate that Pim kinases are plausible therapeutic targets in a readily identifiable subgroup of patients with early RA. Repurposing of Pim inhibitors for this disease should be considered.

Chemokine receptor CCR7 is implicated in the metastasis of breast cancer to the lymph nodes. Chemokine function is dependent upon their binding to both cell-surface heparan sulphate (HS) and to their specific receptors; thus, the role of HS in CCR7-mediated lymph node metastasis was investigated by creating a non-HS binding chemokine CCL21 (mut-CCL21). Mut-CCL21 (Δ103–134) induced leukocyte chemotaxis in diffusion gradients but did not stimulate trans-endothelial migration of PBMCs (p < 0.001) and 4T1-Luc cells (p < 0.01). Furthermore, the effect of heparin and HS on the chemotactic properties of wild-type (WT) and mut-CCL21 was examined. Interestingly, heparin and HS completely inhibit the chemotaxis mediated by WT-CCL21 at 250 and 500 µg/mL, whereas minimal effect was seen with mut-CCL21. This difference could potentially be attributed to reduced HS binding, as surface plasmon resonance spectroscopy showed that mut-CCL21 did not significantly bind HS compared to WT-CCL21. A murine model was used to assess the potential of mut-CCL21 to prevent lymph node metastasis in vivo. Mice were injected with 4T1-Luc cells in the mammary fat pad and treated daily for a week with 20 µg mut-CCL21. Mice were imaged weekly with IVIS and sacrificed on day 18. Luciferase expression was significantly reduced in lymph nodes from mice that had been treated with mut-CCL21 compared to the control (p = 0.0148), suggesting the potential to target chemokine binding to HS as a therapeutic option.

No abstract

No abstract