Suitable human models for the development and characterization of topical compounds for inflammatory skin diseases such as atopic dermatitis are not readily available to date. We describe here the development of a translational model involving healthy human skin mimicking major aspects of AD and its application for the characterization of topical Janus kinase inhibitors. Full thickness human abdominal skin obtained from plastic surgery stimulated in vitro with IL4 and IL13 shows molecular features of AD. This is evidenced by STAT6 phosphorylation assessed by immunohistochemistry and analysis of skin lysates. Broad transcriptome changes assessed by AmpliSeq followed by gene set variation analysis showed a consistent upregulation of gene signatures characterizing AD in this model. Topical application of experimental formulations of compounds targeting the JAK pathway to full thickness skin normalizes the molecular features of AD induced by IL4 and IL13 stimulation. The inhibitory effects of topical JAK inhibitors on molecular features of AD are supported by pharmacokinetic analysis. The model described here is suited for the characterization of topical compounds for AD and has the potential to be extended to other inflammatory skin diseases and pathophysiological pathways.
© 2024 John Wiley & Sons Ltd.

Developing new influenza vaccines with improved performance and easier administration routes hinges on defining correlates of protection. Vaccine-elicited cellular correlates of protection for influenza in humans have not yet been demonstrated. A phase-2 double-blind randomized placebo and active (inactivated influenza vaccine) controlled study provides evidence that a human-adenovirus-5-based oral influenza vaccine tablet (VXA-A1.1) can protect from H1N1 virus challenge in humans. Mass cytometry characterization of vaccine-elicited cellular immune responses identified shared and vaccine-type-specific responses across B and T cells. For VXA-A1.1, the abundance of hemagglutinin-specific plasmablasts and plasmablasts positive for integrin α4β7, phosphorylated STAT5, or lacking expression of CD62L at day 8 were significantly correlated with protection from developing viral shedding following virus challenge at day 90 and contributed to an effective machine learning model of protection. These findings reveal the characteristics of vaccine-elicited cellular correlates of protection for an oral influenza vaccine.
Copyright © 2021 Elsevier Inc. All rights reserved.

The STAT signaling pathway is important in dendritic cell (DC) development and function. Tumor cells can induce STAT signaling, thereby inhibiting DC maturation and immunostimulatory functions, leading to hampered efficacy of DC-based immunotherapies. Platinum-based chemotherapeutics can inhibit STAT signaling, thereby making them an interesting tool to improve DC development and function. In this study, we provide a comprehensive overview of STAT expression and phosphorylation during DC differentiation and maturation and investigate the effects of platinum drugs on STAT signaling during these processes. Monocytes were differentiated into monocyte-derived DCs (moDCs) with IL-4 and GM-CSF and matured with cytokines or TLR ligands. STAT expression and phosphorylation were analyzed by western blotting, and moDC viability and phenotype were analyzed by flow cytometry. Platinum drugs were added at day 3 of differentiation or at the start of maturation to investigate regulation of the STAT signaling pathway. All STAT proteins were expressed during moDC differentiation and STAT1, STAT5, and STAT6 were phosphorylated. No significant changes occurred in the expression and phosphorylation state of the STAT proteins during differentiation. After maturation with TLR ligands, the expression of STAT1 increased, but other STAT proteins were not affected. Phosphorylation of STAT1 and STAT3 increased during maturation, where TLR ligands induced significantly higher levels of phosphorylation than cytokines. Platinum drugs cisplatin and oxaliplatin significantly inhibited phosphorylation of STAT6 during differentiation and maturation. Treatment did not affect the phenotype or viability of the cells. As STAT6 is an important regulator of DC function, these findings suggest a role for platinum-based chemotherapeutics to enhance DC function via inhibition of STAT signaling, thereby potentially enhancing efficacy of DC-based immunotherapies.

Severe acute pancreatitis is associated with systemic inflammation, compensatory immune suppression, secondary infections, vital organ dysfunction, and death.Our study purpose was to delineate signaling profiles of circulating lymphocytes in acute pancreatitis complicated by organ dysfunction.
Sixteen patients with acute pancreatitis, dysfunction of vital organ(s), and immune suppression (proportion of HLA-DR Human Leukocyte Antigen - DR - positive monocytes < 80%) participated. Healthy volunteers served as reference subjects. Using phospho-specific whole blood flow cytometry we studied lymphocyte phosphorylation of nuclear factor-κB (NFκB), mitogen-activated protein kinases p38 and extracellular signal-regulated kinases (ERK)1/2, and signal transducers and activators of transcription (STATs) 1, 3, and 6. Statistical comparisons were performed with the Wilcoxon-Mann-Whitney test.
In blood samples supplemented with tumor necrosis factor, E. coli or S. aureus, phosphorylation levels of NFκB were lower and levels of p38 were higher in patients with acute pancreatitis than healthy subjects. Low NFκB activation involved CD3+CD4+ and CD3+CD8+ lymphocytes. ERK1/2 phosphorylation induced by co-stimulation with phorbol 12-myristate 13-acetate and calcium ionophore A23187 was depressed in patients. STAT3 was constitutively activated in patients' CD3+CD4+ and CD3+CD8+ lymphocytes. Also, IL-6-induced STAT1 phosphorylation was impaired while IL-4-induced STAT6 phosphorylation was enhanced.
Lymphocytes of patients with acute pancreatitis, organ dysfunction and immune suppression show impaired NFκB activation, which increases infection risk and enhanced p38 activation, which sustains inflammation. Secondly, they indicate constitutive STAT3 activation, which may favor Th17 lineage of CD4+ lymphocyte differentiation. Thirdly, they reveal impaired STAT1 activation and enhanced STAT6 activation, denoting a shift from Th1 towards Th2 differentiation.