Full antagonist of the IL-7 receptor suppresses chronic inflammation in non-human primate models by controlling antigen-specific memory T cells

Targeting the expansion of pathogenic memory immune cells is a promising therapeutic strategy to prevent chronic autoimmune attacks. Interleukin 7 (IL-7) is a limiting and potent cytokine produced by epithelial and stromal cells sustaining T-lymphocytes development, homeostasis and cell metabolism. Almost all conventional mature T lymphocytes express the IL-7 receptor (IL-7R), with the exception for naturally-occurring regulatory T-cells (Treg), constituting a rare opportunity to selectively strangle pathogenic effectors while preserving crucial natural regulators. In our recent study, we reported that therapeutic efficacy of antagonist anti- IL-7Rα mAbs in a non-human primate model of memory T cell-induced chronic inflammation depends on recognition of an epitope overlapping the IL-7 binding domain (site 1) and the receptor heterodimerization region (site-2b) (Nat Commun, 9(1):4483). We found that “site-1-only” mAbs prevented IL-7-induced JAK/STAT signaling but induced PI3K and Erk signaling and lacked efficacy in vivo, whereas “site-1 + 2b” mAbs were fully antagonist and demonstrated potent activity to control skin inflammation on the long term. The mechanism of action comprised the neutralization of IFN-γ producing antigen-specific memory T cells, without inducing lymphopenia or polyclonal T-cell functional or metabolic defects as generally observed previously in rodents

Caracterisation of the role of the IL-7/IL-7Rα pathway in inflammatory bowel disease and in type IL-7/IL-7Rα dans

Les maladies inflammatoires chroniques de l’intestin (MICI) sont considérées comme des pathologies multifactorielles. Chez la souris, l’implication de la voie de signalisation de l’IL-7 est établie mais les interprétations restent souvent compliquées à cause de la lymphopénie associée. Chez l’homme, les recherches sont limitées et l’impact du blocage de la voie de l’IL-7 reste peu connu. Dans un premier temps, nous avons déterminé via des méta-analyses l’augmentation de la voie de signalisation de l’IL- 7 chez les patients non répondeurs aux traitements actuels (anti- TNF). De plus, nous avons mis en évidence que cette voie de signalisation était accumulée avant traitement aux anti-TNF chez les patients non répondeurs. En outre, nous avons validé par RT-qPCR, l’augmentation de cette voie ainsi que la corrélation avec l’inflammation, les intégrines α4β7 et la voie du TNF. In vitro, nous avons démontré que l’IL-7 humaine surrégule de façon spécifique chez l’homme et non chez la souris les intégrines α4β7 sur les cellules T effectrices par l’intermédiaire du facteur de transcription CREB. In vivo, dans un modèle de colite chez la NSG humanisée, nous avons déterminé que l’utilisation d’un anti- IL-7Rα était autant efficace que l’utilisation d’un anti-α4β7 afin de prévenir le développement de la colite. Alors que, dans un modèle d’inflammation générale de GVHD chez la NGS humanisée, seul l’anti-IL-7Rα prévient l’infiltration des cellules T dans le colon. Ex-vivo, après 24h de culture des biopsies de patients MICI avec un anti-IL-7Rα, nous avons pu mettre en évidence de façon spécifique, l’action locale et rapide de la diminution de la sécrétion de l’INF-γ. Dans un deuxième temps, nous avons mis en évidence l’implication de la voie de l’IL-7 dans le maintien des cellules mémoires dans un modèle de DTH chez le PNH. L’utilisation d’un anticorps-anti-IL-7Rα a une efficacité in vivo sur le blocage des cellules mémoires passant par le blocage de pSTAT5. Ce blocage induit une délétion clonale antigène-spécifique des clones T mémoires ayant répondu sous traitement, expliquant l’effet protecteur à très long terme (> 1 an) malgré des restimulations antigéniques chroniques mensuelles. Dans l'ensemble, nos résultats justifient une thérapie anti-IL-7Rα qui pourrait offrir une nouvelle opportunité thérapeutique pour prévenir la rechute et fournir une approche thérapeutique pour le rétablissement de la tolérance dans les MICIChronic inflammatory bowel disease is considered as amultifactorial disease. In mice, the involvement of the IL-7 signaling pathway is established but interpretations often remain complicated due to the presence of lymphopenia. In humans, research is limited and the impact of a blockade on the IL-7 pathway is unknown. First of all, we determined with meta-analyzes that the accumulation of the IL-7 signaling pathway in patients not responding to current treatments (anti-TNF). In addition, we showed that this signaling pathway was accumulated before treatment with anti-TNF in non-responding patients. In addition, RT-qPCR validated the accumulation of this pathway as well as the correlation with inflammation, α4β7 integrins and the TNF pathway. In vitro, we demonstrated that human IL-7 specifically up-regulates α4β7 integrins in effector T-cells through the transcription factor CREB in humans and not in mice. In vivo, in a humanized NSG colitis model, we determined that the use of an anti-IL-7Rα was as effective as the use of an anti-α4β7 to prevent development of colitis. While, in a generalized GVHD inflammation model in humanized NGS mice, only anti-IL-7Rα prevents T-cell infiltration into the colon. Ex-vivo, after 24h of biopsy culture from MICI patients with an anti-IL-7Rα, we were able to demonstrate in a specific way, the local and rapid action of the INF-γ secretion decrease. Secondly, we highlighted the involvement of the IL- 7 pathway in the maintenance of memory cells in a DTH model in PNH. Anti-IL-7Rα antibody utilization has an efficacy in vivo on blocking memory cells by pSTAT5 blockade. This blocking induces an antigen-specific clonal deletion of the T-clones which responded under treatment, explaining the very long-term protective effect (> 1 year) in spite of monthly chronic antigenic re-stimulations. Overall, our findings warrant anti-IL-7Rα therapy that could provide a new therapeutic opportunity to prevent relapse and provide a therapeutic approach for restoring tolerance in IBD

IL-7 pathway controls human T cell homing to the gut and culminates in inflammatory bowel disease mucosa

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IL-7 pathway controls human T cell homing to the gut and culminates in inflammatory bowel disease mucosa

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Selective CD28 antagonist prevents Aldara-induced skin inflammation in non-human primates

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Triggering the resolution of inflammation with agonistic anti-ChemR23 antibody dampens inflammation-driven carcinogenesis and metastasis

International audienceTriggering the resolution of inflammation with agonistic anti-ChemR23 antibody dampens inflammation-driven carcinogenesis and metastasis Chronic inflammation is associated with abnormal non-phlogistic clearance (efferocytosis) of apoptotic cells by macrophages and a defect of the resolution of inflammation pathways. The resolution of inflammation is an active immunological process mediated by specialized pro-resolving mediator (SPM) which target specific resolutive G-protein coupled receptors expressed by different immune cells and participate at the return to tissue homeostasis after an injury. Defects in the clearance of (chemotherapy-induced) apoptotic tumor cell debris strengthens inflammation and has been associated with exacerbated tumor growth in several preclinical models. Proresolutive therapeutic approaches, such as using exogenous resolvin E1 (RvE1), the natural lipidic proresolutive ligand of GPCR ChemR23, have been shown to dampen tumor-associated inflammation and to reduce tumor growth. We found that ChemR23 is inducible on myeloid cells by inflammatory stimuli and mainly expressed by tumor associated macrophages in melanoma and lung cancers. We identified an agonist anti-ChemR23 mAb that accelerates the resolution of inflammation in acute inflammatory model in mice. Finally, we report that agonist anti-ChemR23 mAb limits chronic inflammation in the tumor microenvironment and inhibits metastasis development

SIRPγ-CD47 Interaction Positively Regulates the Activation of Human T Cells in Situation of Chronic Stimulation

International audienceA numerous number of positive and negative signals via various molecules modulate T-cell activation. Within the various transmembrane proteins, SIRPg is of interest since it is not expressed in rodents. SIRPg interaction with CD47 is reevaluated in this study. Indeed, wshow that the anti-SIRPg mAb clone LSB2.20 previously used by others has not beenappropriately characterized. We reveal that the anti-SIRPa clone KWAR23 is a Pan antiSIRP mAb which efficiently blocks SIRPa and SIRPg interactions with CD47. We show that SIRPg expression on T cells varies with their differentiation and while being expressed on Tregs, is not implicated in their suppressive functions. SIRPg spatial reorganization atthe immune synapse is independent of its interaction with CD47. In vitro SIRPa-g/CD47 blockade with KWAR23 impairs IFN-g secretion by chronically activated T cells. In vivo in a xeno-GvHD model in NSG mice, the SIRPg/CD47 blockade with the KWAR23 significantlydelays the onset of the xeno-GvHD and deeply impairs human chimerism. In conclusion, we have shown that T-cell interaction with CD47 is of importance notably inchronic stimulation

Selective CD28 antagonist blunts memory immune responses and promotes long-term control of skin inflammation in nonhuman primates

International audienceNovel therapies that specifically target activation and expansion of pathogenic immune cell subsets responsible for autoimmune attacks are needed to confer long-term remission. Pathogenic cells in autoimmunity include memory T lymphocytes that are longlived and present rapid recall effector functions with reduced activation requirements. Whereas the CD28 costimulation pathway predominantly controls priming of naive T cells and hence generation of adaptive memory cells, the roles of CD28 costimulation on established memory T lymphocytes and the recall of memory responses remain controversial. In contrast to CD80/86 antagonists (CTLA4-Ig), selective CD28 antagonists blunt T cell costimulation while sparing CTLA-4 and PD-L1–dependent coinhibitory signals. Using a new selective CD28 antagonist, we showed that Ag-specific reactivation of human memory T lymphocytes was prevented. Selective CD28 blockade controlled both cellular and humoral memory recall in nonhuman primates and induced long-term Ag-specific unresponsiveness in a memory T cell–mediated inflammatory skin model. No modification of memory T lymphocytes subsets or numbers was observed in the periphery, and importantly no significant reactivation of quiescent viruses was noticed. These findings indicate that pathogenic memory T cell responses are controlled by both CD28 and CTLA-4/PD-L1 cosignals in vivo and that selectively targeting CD28 would help to promote remission of autoimmune diseases and control chronic inflammation

Interleukin‐7 receptor blockade by an anti‐ CD 127 monoclonal antibody in nonhuman primate kidney transplantation

International audienceIL‐7 is an important cytokine for T cell lymphopoiesis. Blockade of the IL‐7 signal‐ing pathway has been shown to induce long‐term graft survival or graft tolerance in murine transplant models through inhibiting T cell homeostasis and favoring im ‐munoregulation. In this study, we assessed for the first time the effects of a blocking anti‐human cluster of differentiation 127 (CD127) mAb administered in combination with low‐dose tacrolimus or thymoglobulin in a life‐sustaining kidney allograft model in baboons. Contrary to our expectation, the addition of an anti‐CD127 mAb to the treatment protocols did not prolong graft survival compared to low‐dose tacrolimus alone or thymoglobulin alone. Anti‐CD127 mAb administration led to full CD127 re ‐ceptor occupancy during the follow‐up period. However, all treated animals lost their kidney graft between 1 week and 2 weeks after transplantation. Unlike in rodents, in nonhuman primates, anti‐CD127 mAb treatment does not decrease the absolute numbers of lymphocyte and lymphocyte subsets and does not effectively inhibit postdepletional T cell proliferation and homeostasis, suggesting that IL‐7 is not a lim ‐iting factor for T cell homeostasis in primates