187 Glucocorticoid regulation of the type I interferon-JAK/STAT signaling pathway

Abstract Background and Aims TOMOGRAM, multicenter study founded by DESCARTES ERA/EDTA WG, aims to identify transcriptomic and genomic signatures of operational tolerance (OT) in recently identified cohort of OT kidney transplant recipients. Method RNA sequencing of peripheral blood was evaluated in 15 OT patients recently identified by TOMOGRAM consortium in 8 European countries, 23 stable patients (≥ 15 years on immunosuppression, STA), 14 CABMR patients (≥ 1 year, CR), 14 non-transplant CNI-treated patients and 14 healthy controls (HC). Differential expression was performed using DESEq2 and gene annotation analysis using Enrichr. Besides immunosuppression unadjusted model, robust negative-binomial regression model was created to adjust for immunosuppression intake. The models was trained on homogeneous group of STA patients. Results Using model unadjusted for immunosuppression, no differences in transcriptomic profiles between OT, STA and HC groups were identified. Nine transcripts were upregulated and 2 downregulated in OT compared CR group. The number of deregulated transcripts substantially increased when the model was adjusted for immunosuppression. Gene annotation analysis of top ranked deregulated 1109 transcripts (FC>2, adjusted p value <0.0001) showed deregulation of biological processes related to interferon-γ-mediated signaling pathway (p=1.4*10-5), response to cytokine (p=1.5*10-5), type I interferon signaling pathway (p=0.00036), regulation of I-kappaB kinase/NF-kappaB signaling (p=0.0021), cytokine-mediated signaling pathway (p=0.019) and neutrophil mediated immunity (p=0.033). While interferon-γ-mediated and type I interferon signaling were related to transcripts increased in CR, neutrophils associated transcripts were increased in OT. Analysis of cell types transcripts showed enrichment of CD19 B cells (p=1.6*10-9) in CR, while CD56NK cells (p=2.5*10-11) and CD8 T cells (p=1.6*10-11) transcripts predominated in OT. To reveal probability of operational tolerance inside STA group, 13 transcripts able to discriminate OT and CR cohorts with high AUC (>0.89) were used in PCA analysis (ADGRG3, ATG2A, GDPD5, IL16, MX2, SLA2, PRKD2, SLIRP, GNLY, SRCAP, ARGHAP9, IGHM, CD5). The high probability of OT signature was found in a single STA patient. Conclusion Contrary to previous reports which pointed out towards naïve B cell signatures, unique OT patients exhibit other specific immunosuppression-independent transcriptomic profiles.

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Hemagglutinin of Influenza A Virus Antagonizes Type I Interferon (IFN) Responses by Inducing Degradation of Type I IFN Receptor 1

Journal of Virology ◽

10.1128/jvi.02749-15 ◽

2015 ◽

Vol 90 (5) ◽

pp. 2403-2417 ◽

Cited By ~ 41

Author(s):

Chuan Xia ◽

Madhuvanthi Vijayan ◽

Curtis J. Pritzl ◽

Serge Y. Fuchs ◽

Adrian B. McDermott ◽

...

Keyword(s):

Signaling Pathway ◽

Influenza A Virus ◽

Influenza A ◽

Type I Interferon ◽

Innate Immune ◽

Host Cells ◽

Type I ◽

Type I Ifn ◽

Type I Ifns ◽

Ha Protein

ABSTRACTInfluenza A virus (IAV) employs diverse strategies to circumvent type I interferon (IFN) responses, particularly by inhibiting the synthesis of type I IFNs. However, it is poorly understood if and how IAV regulates the type I IFN receptor (IFNAR)-mediated signaling mode. In this study, we demonstrate that IAV induces the degradation of IFNAR subunit 1 (IFNAR1) to attenuate the type I IFN-induced antiviral signaling pathway. Following infection, the level of IFNAR1 protein, but not mRNA, decreased. Indeed, IFNAR1 was phosphorylated and ubiquitinated by IAV infection, which resulted in IFNAR1 elimination. The transiently overexpressed IFNAR1 displayed antiviral activity by inhibiting virus replication. Importantly, the hemagglutinin (HA) protein of IAV was proved to trigger the ubiquitination of IFNAR1, diminishing the levels of IFNAR1. Further, influenza A viral HA1 subunit, but not HA2 subunit, downregulated IFNAR1. However, viral HA-mediated degradation of IFNAR1 was not caused by the endoplasmic reticulum (ER) stress response. IAV HA robustly reduced cellular sensitivity to type I IFNs, suppressing the activation of STAT1/STAT2 and induction of IFN-stimulated antiviral proteins. Taken together, our findings suggest that IAV HA causes IFNAR1 degradation, which in turn helps the virus escape the powerful innate immune system. Thus, the research elucidated an influenza viral mechanism for eluding the IFNAR signaling pathway, which could provide new insights into the interplay between influenza virus and host innate immunity.IMPORTANCEInfluenza A virus (IAV) infection causes significant morbidity and mortality worldwide and remains a major health concern. When triggered by influenza viral infection, host cells produce type I interferon (IFN) to block viral replication. Although IAV was shown to have diverse strategies to evade this powerful, IFN-mediated antiviral response, it is not well-defined if IAV manipulates the IFN receptor-mediated signaling pathway. Here, we uncovered that influenza viral hemagglutinin (HA) protein causes the degradation of type I IFN receptor subunit 1 (IFNAR1). HA promoted phosphorylation and polyubiquitination of IFNAR1, which facilitated the degradation of this receptor. The HA-mediated elimination of IFNAR1 notably decreased the cells' sensitivities to type I IFNs, as demonstrated by the diminished expression of IFN-induced antiviral genes. This discovery could help us understand how IAV regulates the host innate immune response to create an environment optimized for viral survival in host cells.

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