BackgroundImmunotherapies still fail to benefit colorectal cancer (CRC) patients. Relevant functional assays aimed at studying these failures and the efficacy of cancer immunotherapy in human are scarce. 3D tumor cultures, called tumor organoids or spheroids, represent interesting models to study cancer treatments and could help to challenge these issues.MethodsWe analyzed heterotypic cocultures of human colon tumor-derived spheroids with immune cells to assess the infiltration, activation and function of T and NK cells toward human colorectal tumors in vitro.ResultsWe showed that allogeneic T and NK cells rapidly infiltrated cell line-derived spheroids, inducing immune-mediated tumor cell apoptosis and spheroid destruction. NKG2D, a key activator of cytotoxic responses, was engaged on infiltrating cells. We thus assessed the therapeutic potential of an antibody targeting the specific ligands of NKG2D, MICA and MICB, in this system. Anti-MICA/B enhanced immune-dependent destruction of tumor spheroid by driving an increased NK cells infiltration and activation. Interestingly, tumor cells reacted to immune infiltration by upregulating HLA-E, ligand of the inhibitory receptor NKG2A expressed by CD8 and NK cells. NKG2A was increased after anti-MICA/B treatment and, accordingly, combination of anti-MICA/B and anti-NKG2A was synergistic. These observations were ultimately confirmed in a clinical relevant model of coculture between CRC patients-derived spheroids and autologous tumor-infiltrating lymphocytes.ConclusionsAltogether, we show that tumor spheroids represent a relevant tool to study tumor-lymphocyte interactions on human tissues and revealed the antitumor potential of immunomodulatory antibodies targeting MICA/B and NKG2A.Electronic supplementary materialThe online version of this article (10.1186/s40425-019-0553-9) contains supplementary material, which is available to authorized users.
Intestinal tissue-resident memory CD8 T cells (Trm) are non-recirculating effector cells ideally positioned to detect and react to microbial infections in the gut mucosa. There is an emerging understanding of Trm cell differentiation and functions, but their implication in inflammatory bowel diseases, such as Crohn's disease (CD), is still unknown. Here, we describe CD8 cells in the human intestine expressing KLRG1 or CD103, two receptors of E-cadherin. While CD103 CD8 T cells are present in high numbers in the mucosa of CD patients and controls, KLRG1 CD8 T cells are increased in inflammatory conditions. Mucosal CD103 CD8 T cells are more responsive to TCR restimulation, but KLRG1 CD8 T cells show increased cytotoxic and proliferative potential. CD103 CD8 T cells originate mostly from KLRG1 negative cells after TCR triggering and TGFβ stimulation. Interestingly, mucosal CD103 CD8 T cells from CD patients display major changes in their transcriptomic landscape compared to controls. They express Th17 related genes including CCL20, IL22, and IL26, which could contribute to the pathogenesis of CD. Overall, these findings suggest that CD103 CD8 T cells in CD induce a tissue-wide alert increasing innate immune responses and recruitment of effector cells such as KLRG1 CD8 T cells.
This article has an accompanying continuing medical education activity, also eligible for MOC credit, on page e9. Learning Objective-Upon completion of this activity, successful learners will be able to list risk factors for postoperative recurrence in Crohn's disease; list appropriate strategies to evaluate for early disease recurrence following surgery for Crohn's disease; and outline treatment options to reduce risk of postoperative recurrence in Crohn's disease, and strategies if early recurrence is identified. BACKGROUND AND AIMS: Different types of histologic lesions at the ileal margin, detected by histology, have been associated with increased rates of recurrence after ileocaecal surgery in patients with Crohn's disease (CD). We aimed to characterize histologic features of the ileal margin and to evaluate their association with disease recurrence. METHODS: We collected histologic data from 211 patients with ileal or ileocolonic CD who underwent ileocolonic resections at hospitals in France from September 2010 through December 2016. Ileal margins were analyzed. Early endoscopic recurrence was defined by a Rutgeerts score of i2 or more, 6 months after surgery. We also collected data from 10 adults with healthy ileum who underwent ileocecal resection for colonic tumors (controls). Clinical relapse was defined by CD-related symptoms confirmed by imaging, endoscopy, therapy intensification, CD-related complication, or subsequent surgery. RESULTS: Six months after surgery, 49% of patients had endoscopic recurrence; 5 years after surgery, 57% of patients had clinical relapse. Ileal margins were macroscopically affected in 20.9% of patients. CD transmural lesions at the margin (defined by mucosal ulceration or cryptitis, submucosal fibrosis and lymphoplasmacytic infiltrate of the subserosa) were observed in 13.6% of patients. Endoscopic recurrence was observed in 75% of patients with CD transmural lesions vs 46% of patients without (P [.005). In multivariate analysis, CD transmural lesions at the margin were independently associated with early endoscopic recurrence (OR, 3.83; 95% CI, 1.47-11.05; P [.008) and clinical recurrence (OR 2.04; 95% CI, 1.09-3.99; P [.026). CONCLUSION: In patients with CD, transmural lesions at the ileal margin were associated with an increased risk of post-operative recurrence. Histologic features of the ileal margin should be included in making decisions about post-operative therapy.
T cell clonal expansions are present in the inflamed mucosa of patients with Crohn’s disease (CD) and may be implicated in postoperative recurrence after ileocolonic resection.MethodsT cell receptor (TCR) analysis was performed in 57 patients included in a prospective multicentre cohort. Endoscopic recurrence was defined by a Rutgeerts score >i0. DNA and mRNA were extracted from biopsies collected from the surgical specimen and endoscopy, and analysed by high throughput sequencing and microarray, respectively.ResultsTCR repertoire in the mucosa of patients with CD displayed diverse clonal expansions. Active smokers at time of surgery had a significantly increased proportion of clonal expansions as compared with non-smokers (25.9%vs17.9%, p=0.02). The percentage of high frequency clones in the surgical specimen was significantly higher in patients with recurrence and correlated with postoperative endoscopic recurrence (area under the curve (AUC) 0.69, 95% CI 0.54 to 0.83). All patients with clonality above 26.8% (18/57) had an endoscopic recurrence. These patients with a high clonality were more frequently smokers than patients with a low clonality (61% vs 23%, p=0.005). The persistence of a similar TCR repertoire at postoperative endoscopy was associated with smoking and disease recurrence. Patients with high clonality showed increased expression of genes associated with CD8 T cells and reduced expression of inflammation-related genes. Expanded clones were found predominantly in the CD8 T cell compartment.ConclusionClonal T cell expansions are implicated in postoperative endoscopic recurrence. CD patients with increased proportion of clonal T cell expansions in the ileal mucosa represent a subgroup associated with smoking and where pathogenesis appears as T cell driven.Trial registration numberNCT03458195.
Background and aims Ileocolonic resection is frequently needed in the course of Crohn’s disease (CD) and post-operative recurrence is extremely common. Our main objective was to analyze gene expression in the mucosa of CD patients at time of surgery and post-operative endoscopy, in order to identify predictors and mechanisms of early endoscopic recurrence. Methods We conducted transcriptome analyses on ileal mucosa samples collected from inflamed sections of the surgical specimens (n=200), from ileal resection margins (n=149) and in the neo-terminal ileum 6 months after surgery (n=122); with non-IBD controls (n=25). The primary endpoint was post-operative endoscopic recurrence at month 6. We applied regression models to identify gene signatures predicting endoscopic recurrence. Results Chronic inflammation was associated with strong expression of inflammatory genes (IL-6, IL-8, IL-1B) and decreased expression of genes involved in metabolic processes, but with a high inter-individual heterogeneity. Gene signatures associated with early endoscopic recurrence was mainly characterized by upregulation of TNFα, IFNγ, IL23A, and IL17A. Pathway analyses showed that upregulation of mitochondrial dysfunction within the inflammation and the JAK/STAT at the ileal margin were predictive of post-operative recurrence. A combined model integrating these top pathway signatures improved the prediction of endoscopic recurrence (AUC of 0.79). STAT3 phosphorylation at the surgical ileal margin was associated with severe recurrence at six months. Conclusion We identify several biological pathways in the surgical specimen associated with an increased risk of disease recurrence. Integration of JAK/STAT and mitochondrial dysfunction pathways in the clinical model improved the prediction of post-operative recurrence.
Lympho-epithelial interactions between intestinal T resident memory cells (Trm) and the epithelium have been associated with inflammatory bowel disease (IBD) activity. We developed ex vivo autologous organoid-mucosal T cell cocultures to functionally assess lymphoepithelial interactions in Crohn’s Disease (CD) patients compared to controls. We demonstrate the direct epithelial cell death induced by autologous mucosal T cells in CD patients but not in controls. These findings were positively correlated with T cell infiltration of the organoids. This potential was inhibited by limiting lympho-epithelial interactions through CD103 and NKG2D blocking antibodies. These data directly demonstrate for the first time the direct deleterious effect of mucosal T cells on the epithelium of CD patients. Such ex-vivo models are promising techniques to unravel the pathophysiology of these diseases and the potential mode of action of current and future therapies.
Background T resident memory (Trm) cells in the intestinal mucosa and in particular subpopulations expressing phenotypic markers such as alphaE-beta7 or NKG2D have been associated with chronic inflammatory bowel disease (IBD) activity. We hypothesize that these populations may have a direct deleterious impact on the intestinal epithelium in IBD. Methods The phenotypic study of mucosal lymphocytes was performed in two prospective cohorts: ELYP including patients with active IBD before initiation of biotherapy and REMIND including patients with ileal Crohn’s disease (CD) requiring ileocaecal resection. These analyses were performed before initiation of treatment and one year after continuous therapy in the ELYP cohort and on the resection specimen in the REMIND cohort. An innovative ex vivo autologous organoid-mucosal T cell coculture model was developed using the REMIND cohort specimens for patients and healthy ileum from individuals without IBD for controls (Figure 1). T cell infiltration within the organoid and epithelial cell death were assessed by confocal microscopy. A panel of 30 cytokines was quantified in the supernatants of cocultures. Figure 1 Results In the ELYP cohort, before the start of treatment, IBD patients had lower expression of alphaE-beta7 and NKG2D on mucosal CD8 T cells. While alphaE-beta7 and NKG2D expression on mucosal CD8 T cells had returned to normal in endoscopic responders, it remained decreased in non-responders. Similarly, the inflammatory mucosa of the REMIND surgical specimens had lower levels of CD4 and CD8 T cells expressing alphaE-beta7 and NKG2D compared with controls and non-inflamed regions. We developed a coculture model between mucosal lymphocytes and organoids generated under autologous conditions. We showed an increase in apoptotic cell death in epithelial cells from CD patients which was not found in control cocultures. There was a significant correlation between the degree of epithelial cell death and T cell infiltration (Figure 2). Various proinflammatory cytokines such as IFNgamma, TNFalpha, IL-6 and IL- 17a were also increased in the supernatants. The use of antibodies blocking the alphaE-beta7 and NKG2D pathways of interest inhibited this effect by different mechanisms (Figure 3) While anti-beta7 and anti-NKG2D had comparable effects in terms of cell death inhibition, only anti-beta7 reduced T cell infiltration. Anti-NKG2D had no effect on cell infiltration but a reduction of perforin was observed in the supernatants. Figure 2 Figure 3 CC= Coculture Conclusion These data demonstrate for the first time the direct cytotoxic deleterious effect of mucosal T cells on the epithelium of CD patients using a novel coculture model. AlphaE-beta7 and NKG2D pathways appear to be relevant in this process.
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