Epithelial IL-1R2 acts as a homeostatic regulator during remission of ulcerative colitis

[eng] Ulcerative colitis (UC) is an idiopathic chronic inflammatory disease of the large intestine. In most patients UC runs a remitting and relapsing course, with periods of active disease followed by phases of inactivity. Although current therapeutic options can induce remission in about 30-70% of patients, continuous pharmacological treatment is often required to avoid disease relapse. In order to promote sustained remission, endogenous mechanisms that support intestinal homeostasis and contain arising local inflammation must be identified. We aimed to identify endogenous regulatory mechanisms that may promote disease remission. Transcriptional and protein analysis of the intestinal mucosa revealed that the IL-1 decoy receptor, interleukin-1 receptor type 2 (IL1R2), was up-regulated in remission compared to active UC and controls. IL-1R2 serves as a potent inhibitor of IL- 1 signaling by competing with IL-1R1 for IL-1, and by subsequently forming a complex with IL-1RAcP, thereby sequestering both the ligand and the accessory protein required for signal transduction. We identified both IgA (but not IgG ) plasma cells and mucosal epithelial cells as the main producers of IL-1R2 in human colon. In order to determine IL-1R2 expression by epithelial cells, we used flow cytometry to quantify IL-1R2 production by the epithelial compartment in colonic biopsies. Samples from the involved mucosa of + UC in remission showed a significantly higher percentage of intracellular, IL-1R2 cells - + among CD45 Ep-CAM epithelial cells compared to control, uninvolved UC, and active UC samples. Immunostaining analysis of colonic mucosa revealed a gradient expression of IL-1R2 along the crypt. In vitro expanded colonic stem cells (CoSCs) can be induced to differentiate by removing Wnt/beta-catenin activating signals from the culture media. Using this system, we demonstrated that both IL1R2 gene transcription and IL-1R2 protein secretion is significantly increased upon CoSCs in vitro differentiation. Using an ex vivo culture of intestinal epithelial crypts, we provide here novel evidence for the role of beta-catenin signaling in repressing IL-1R2 transcription and translation. Canonical Wnt signals activate beta-catenin and are critically involved in stem-cell proliferation and survival at the base of the intestinal crypts. Moreover, blocking IL-1R2 in isolated colonic crypt cultures of UC patients in remission and T cell cultures stimulated with biopsy supernatant from UC patients in remission boosted IL-1β-dependent production of inflammation-related cytokines. Our final objective was to address whether IL-1R2 overexpression could be related to disease outcome. In order to test this possibility, we looked at IL1R2 transcription in a cohort of UC patients in endoscopic and histologic remission that were followed up for one year after taking biopsies from the distal colon. IL1R2 transcription was significantly lower in the group of patients that relapsed during the follow-up period of 12 months compared with those patients that remained in endoscopic remission for the same amount of time. Interestingly, in patients who relapsed, IL1R2 expression negatively correlated with IFNG transcription. These data suggest that IL-1R2 may play a role in preventing disease relapse. Collectively our results reveal that the IL-1/IL-1R2 axis is differentially regulated in the remitting intestinal mucosa of UC patients. We hypothesize that IL-1R2 in the presence of low concentrations of IL-1 may act locally as a regulator of intestinal homeostasis

CD49a Regulates Cutaneous Resident Memory CD8(+) T Cell Persistence and Response

Luster, Andrew/0000-0001-9679-7912; Chasse, Alexandra/0000-0001-7970-2053WOS: 000565154100003PubMed: 32877667CD8(+) tissue-resident memory T cells (T-RM) persist at sites of previous infection, where they provide rapid local protection against pathogen challenge. CD8(+) T-RM expressing the alpha 1 chain (CD49a) of integrin VLA-1 have been identified within sites of resolved skin infection and in vitiligo lesions. We demonstrate that CD49a is expressed early following T cell activation in vivo, and TGF-beta and IL-12 induce CD49a expression by CD8(+ )T cells in vitro. Despite this rapid expression, CD49a is not required for the generation of a primary CD8(+) T cell response to cutaneous herpes simplex virus (HSV) infection, migration of CD8(+) T cells across the epidermal basement membrane, or positioning of T-RM within basal epidermis. Rather, CD49a supports CD8(+) T-RM persistence within skin, regulates epidermal CD8(+) T-RM dendritic extensions, and increases the frequency of IFN-gamma(+) CD8(+) T-RM following local antigen challenge. Our results suggest that CD49a promotes optimal cutaneous CD8(+) T-RM-mediated immunity.NIHUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [R01 AI121546]; [HSV-1 gB 498-505 SSIEFARL]We would like to thank Dr. David Topham for providing Itga1-/- mice, Dr. David Knipe for providing HSV-KOS and advice on working with HSV, and Dr. Thomas Gebhardt for providing HSV-OVA. the following reagent was obtained through the NIH TetramerCore Facility: H-2K(b) HSV-1 gB 498-505 SSIEFARL. the graphical abstract was produced using BioRender. This work was supported by NIH grant R01 AI121546 (to S.K.B.)

Migratory DCs activate TGF-β to precondition naïve CD8+ T cells for tissue-resident memory fate

Epithelial resident memory T (eTRM) cells serve as sentinels in barrier tissues to guard against previously encountered pathogens. How eTRM cells are generated has important implications for efforts to elicit their formation through vaccination or prevent it in autoimmune disease. Here, we show that during immune homeostasis, the cytokine transforming growth factor β (TGF-β) epigenetically conditions resting naïve CD8+ T cells and prepares them for the formation of eTRM cells in a mouse model of skin vaccination. Naïve T cell conditioning occurs in lymph nodes (LNs), but not in the spleen, through major histocompatibility complex class I-dependent interactions with peripheral tissue-derived migratory dendritic cells (DCs) and depends on DC expression of TGF-β-activating αV integrins. Thus, the preimmune T cell repertoire is actively conditioned for a specialized memory differentiation fate through signals restricted to LNs

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

non present