Biology subjects

Josien, R.

Publications and source records attributed to Josien, R..

7 recordsLinked to original sources

bioRxiv2023

Myeloid cell influx into the colonic epithelium is associated with disease severity and non-response to anti-Tumor Necrosis Factor Therapy in patients with Ulcerative Colitis.

Ulcerative colitis (UC) is an idiopathic chronic inflammatory disease of the colon with sharply rising global prevalence. Dysfunctional epithelial compartment (EC) dynamics are implicated in UC pathogenesis although EC-specific studies are sparse. Applying orthogonal high-dimensional EC profiling to a Primary Cohort (PC; n=222), we detail major epithelial and immune cell perturbations in active UC. Prominently, reduced frequencies of mature BEST4+OTOP2+ absorptive and BEST2+WFDC2+ secretory epithelial enterocytes were associated with the replacement of homeostatic, resident TRDC+KLRD1+HOPX+ {gamma}{delta}+ T cells with RORA+CCL20+S100A4+ TH17 cells and the influx of inflammatory myeloid cells. The EC transcriptome (exemplified by S100A8, HIF1A, TREM1, CXCR1) correlated with clinical, endoscopic, and histological severity of UC in an independent validation cohort (n=649). Furthermore, therapeutic relevance of the observed cellular and transcriptomic changes was investigated in 3 additional published UC cohorts (n=23, 48 and 204 respectively) to reveal that non-response to anti-Tumor Necrosis Factor (anti-TNF) therapy was associated with EC related myeloid cell perturbations. Altogether, these data provide high resolution mapping of the EC to facilitate therapeutic decision-making and personalization of therapy in patients with UC.

immunology↗

bioRxiv2023

A gene-expression module in circulating immune cells is associated with cell migration during immune diseases.

Circulating immune cells are critical mediators of inflammation upon recruitment to tissues, yet how their gene expression state influences this recruitment is not well understood. Here, we report longitudinal single-cell transcriptome profiling of peripheral blood mononuclear cells in patients undergoing kidney transplantation rejection. We identify a novel gene expression module, termed ALARM (early activation transcription factor module), associated with transcriptional regulation, homing, and immune activation across multiple immune cell types. Circulating cells expressing this module are significantly reduced in patients experiencing graft rejection, a finding confirmed in a pig model of acute kidney transplantation rejection. Correspondingly, module expression is markedly increased in kidney grafts undergoing rejection, indicating preferential recruitment of ALARM-expressing cells to the inflamed tissue. Within this module, we identify the receptor CXCR4 and its ligand CXCL12, expressed in the graft, as a likely mechanism for recruitment. In vitro transwell assays combined with scRNA-seq reveal that this CXCR4-CXCL12 interaction is critical for T cell migration and upregulation of CD69, an early activation marker, and is accompanied by a metabolic switch towards glycolysis. Further exploration of publicly available transcriptomic data demonstrates that this module is generally expressed in healthy individuals and is strongly associated with responses to infection, including SARS-CoV-2 infection. This finding is further supported by experiments in a pneumonia mouse model, which confirm the recruitment of CXCR4-expressing T cells during lung infection. Moreover, we find that module expression is predictive of immune-mediated diseases. In summary, we have identified a key gene expression module in circulating immune cells that orchestrates their preferential recruitment to inflamed tissues, metabolic reprogramming, promoting tissue residency and effector functions. These insights advance our understanding of immune cell recruitment and activation mechanisms in transplant rejection and infectious diseases, with potential implications for therapeutic interventions.

immunology↗

bioRxiv2021

Characterization of IL-22BP expression during Crohn's disease shows lack of evidence for IL-22BP production by T cells

Crohns disease (CD), a form of inflammatory bowel disease (IBD), is characterized by impaired epithelial barrier functions and dysregulated mucosal immune responses. IL-22 binding protein (IL-22BP) is a soluble inhibitor regulating IL-22 bioactivity, a cytokine proposed to play protective roles during CD. We and others have shown that IL-22BP is produced in IBD inflamed tissues, hence suggesting a role in CD. In this work, we extended the characterization of IL-22BP production and distribution in CD tissues by applying enzyme-linked immunosorbent assays to supernatants obtained from the culture of endoscopic biopsies of patients, and reverse transcription-quantitative polymerase chain reaction on sorted immune cell subsets. We reveal that IL-22BP levels are higher in inflamed ileums than colons. We observe that in a cell-intrinsic fashion, populations of mononuclear phagocytes and eosinophils express IL-22BP at the highest levels in comparison to other sources of T cells. We suggest the enrichment of intestinal eosinophils could explain higher IL-22BP levels in the ileum. In inflamed colon, we reveal the presence of increased IL-22/IL22BP ratios compared to controls, and a strong correlation between IL-22BP and CCL24. We identify monocyte-derived dendritic cells (moDC) as a cellular subtype co-expressing both cytokines and validate our finding using in vitro culture systems. We also show that retinoic acid induces the secretion of both IL-22BP and CCL24 by moDC. Finally, we report on higher IL-22BP levels in active smokers. In conclusion, our work provides new information relevant to therapeutic strategies modulating IL-22 bioactivity in CD, especially in the context of disease location.

immunology↗

bioRxiv2020

Non-permissive human conventional CD1c+ dendritic cells enable trans-infection of human primary renal tubular epithelial cells and protect BK polyomavirus from neutralization

The BK polyomavirus (BKPyV) is a ubiquitous human virus that persists in the renourinary epithelium. Immunosuppression can lead to BKPyV reactivation in the first year post-transplantation in kidney (KTR) and hematopoietic stem cell transplant recipients. In KTR, persistent DNAemia has been correlated to the occurrence of polyomavirus-associated nephropathy (PVAN) that can lead to graft loss if not properly controlled. Based on recent observations that conventional dendritic cells (cDC) specifically infiltrate PVAN lesions, we hypothesized that those cells could play a role in BKPyV infection. We first demonstrated that monocyte-derived DC (MDDC), an in vitro model for mDC, captured BKPyV particles through an unconventional GRAF-1 endocytic pathway. Neither BKPyV particles nor BKPyV-infected cells were shown to activate MDDC. Endocytosed virions were efficiently transmitted to permissive cells and shown to be protected from the antibody-mediated neutralization. Finally, we demonstrated that freshly isolated CD1c+ mDC from the blood and kidney parenchyma behaved similarly to MDDC thus extending our results to cells of clinical relevance. This study sheds light on a potential unprecedented CD1c+ mDC involvement in the BKPyV infection as a promoter of viral spreading.

microbiology↗

bioRxiv2020

An easy and reliable whole blood freezing method for flow cytometry immuno- phenotyping and functional analyses

BackgroundImmune profiling by flow cytometry is not always possible on fresh blood samples due to time and/or transport constraints. Besides, the cryopreservation of peripheral blood mononuclear cells (PBMC) requires on-site specialized lab facilities, thus severely restricting the extent by which blood immune monitoring can be applied to multicenter clinical studies. These major limitations can be addressed through the development of simplified whole blood freezing methods. MethodsIn this report, we describe an optimized easy protocol for rapid whole blood freezing with the CryoStor(R) CS10 solution. Using flow cytometry, we compared cellular viability and composition on cryopreserved whole blood samples to matched fresh blood, as well as fresh and frozen PBMC. ResultsThough partial loss of neutrophils was observed, leucocyte viability was routinely >75% and we verified the preservation of viable T cells, NK cells, monocytes, dendritic cells and eosinophils in frequencies similar to those observed in fresh samples. A moderate decrease in B cell frequencies was observed. Importantly, we validated the possibility to analyze major intracellular markers, such as FOXP3 and Helios in regulatory T cells. Finally, we demonstrated good functional preservation of CS10-cryopreserved cells through the analysis of intracellular cytokine production in ex vivo stimulated T cells (IFNg, IL-4, IL-17A,) and monocytes (IL-1b, IL-6, TNFa). ConclusionsIn conclusion, our protocol provides a robust method to apply reliable immune monitoring studies to cryopreserved whole blood samples, hence offering new important opportunities for the design of future multicenter clinical trials.

immunology↗

bioRxiv2019

Dendritic cells require TMEM176A/B ion channels for optimal MHC II antigen presentation to naive CD4+ T cells

Intracellular ion fluxes emerge as critical actors of immunoregulation but still remain poorly explored. Here we investigated the role of the redundant cation channels TMEM176A and TMEM176B (TMEM176A/B) in ROR{gamma}t+ cells and conventional dendritic cells (cDCs) using germline and conditional double knock-out (DKO) mice. While Tmem176a/b appeared surprisingly dispensable for the protective function of Th17 and group 3 innate lymphoid cells (ILC3s) in the intestinal mucosa, we found that they were required in cDCs for optimal antigen processing and presentation to CD4+ T cells. Using a real-time imaging method, we show that TMEM176A/B accumulate in dynamic post-Golgi vesicles preferentially linked to the late endolysosomal system and strongly colocalize with HLA-DM. Together, our results suggest that TMEM176A/B ion channels play a direct role in the MHC II compartment (MIIC) of DCs for the fine regulation of antigen presentation and naive CD4+ T cell priming.

immunology↗

bioRxiv2018

Immunological characterization of a rat model of Duchenne’s disease and demonstration of improved muscle strength after anti-CD45RC antibody treatment

Duchenne muscular dystrophy (DMD) has as standard pharmacological therapy with corticoisteroids (CS) that decrease inflammation and immune responses present in patients and animal models. CS have however limited efficacy and important and numerous side effects. Therefore, there is a need for new anti-inflammatory and pro-tolerogenic treatments that could replace or decrease doses of CS. We first assessed the status of immune system of dystrophin-deficient rats (Dmdmdx) that closely reproduce the phenotype of DMD patients. Dmdmdx rats showed increased leukocyte infiltration in skeletal and cardiac muscles, containing mostly macrophages but also T cells, and increased expression of several cytokines. Anti-CD45RC Monoclonal antibody (Mab) treatment induced immune tolerance in models of organ transplantation and GVHD (Graft Versus Host Disease). We observed that muscles and blood of DMD patients contained T CD4+ and CD8+ expressing high levels of CD45RChigh cells. Treatment of young Dmdmdx rats with anti-CD45RC MAb corrected skeletal muscle strength associated to a depletion of effectors CD45RChigh T cells with no obvious side-effects. Prednisolone treatment of Dmdmdx rats similarly increased skeletal muscle strength and was also associated to a depletion of effectors CD45RChigh cells but resulted in severe weight loss.\n\nOverall, Dmdmdx rats display important immune inflammatory response and thus represent a useful model to analyze new anti-inflammatory and tolerogenic treatments for DMD. As an example, a new treatment with anti-CD45RC antibodies improved muscle strength in Dmdmdx rats as prednisolone did but without side effects. Anti-CD45RC therapy could complement other therapies in DMD patients.

immunology↗