SIRPa agonist antibody treatment ameliorates experimental arthritis and colitis [sequencing]
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ABSTRACT: The innate immune system is finely tuned to enable rapid response to pathogenic stimuli but keep quiescent during tissue homeostasis.Balance of activating and inhibitory signaling sets a threshold for immune activation. Signal regulatory protein (SIRPa) is an immune inhibitory receptor expressed by myeloid cells and interacts with CD47 to inhibit immune cell phagocytosis, migration, and activation. Despite the progress of SIRPa and CD47 antagonist antibodies to promote anti-cancer immunity, it is not yet known whether therapeutic SIRPa receptor agonism could restrain excessive autoimmune inflammation in the context of autoimmunity. Here, we reported that increased neutrophil- and monocyte-associated genes including SIRPA in inflamed tissues biopsies of rheumatoid arthritis and inflammatory bowel diseases, and elevated SIRPA in colonic biopsies is associated with treatment refractory ulcerative colitis patients. We next identified a novel agonistic anti-SIRPa antibody that exhibited potent anti-inflammatory effects in reducing neutrophil and monocytes chemotaxis and tissue infiltration. In preclinical models of arthritis and colitis, anti-SIRPa agonistic antibody ameliorates autoimmune joint inflammation and inflammatory colitis through reducing neutrophils and monocytes in tissues. Our work provides a proof-of-concept for SIRPa receptor agonism for suppressing excessive innate immune activation and autoimmune inflammatory therapeutic treatment
Project description:The innate immune system is finely tuned to enable. rapid response to pathogenic stimuli but keep quiescent during tissue homeostasis. Balance of activating and inhibitory signaling sets a threshold for immune activation. Signal regulatory protein (SIRPa) is an immune inhibitory receptor expressed by myeloid cells and interacts with CD47 to inhibit immune cell phagocytosis, migration, and activation. Despite the progress of SIRPa and CD47 antagonist antibodies to promote anti-cancer immunity, it is not yet known whether therapeutic SIRPa receptor agonism could restrain excessive autoimmune inflammation in the context of autoimmunity. Here, we reported that increased neutrophil- and monocyte-associated genes including SIRPA in inflamed tissues biopsies of rheumatoid arthritis and inflammatory bowel diseases, and elevated SIRPA in colonic biopsies is associated with treatment refractory ulcerative colitis patients. We next identified a novel agonistic anti-SIRPa antibody that exhibited potent anti-inflammatory effects in reducing neutrophil and monocytes chemotaxis and tissue infiltration. In preclinical models of arthritis and colitis, anti-SIRPa agonistic antibody ameliorates autoimmune joint inflammation and inflammatory colitis through reducing neutrophils and monocytes in tissues. Our work provides a proof-of-concept for SIRPa receptor agonism for suppressing excessive innate immune activation and autoimmune inflammatory therapeutic treatment
Project description:SIRPa-CD47 “don’t eat me” checkpoint axis plays a critical role in defining anti-tumor activities of macrophages within the tumor microenvironment. However, targeting this axis with anti-CD47 antibodies to improve anti-tumor responses in clinical trials has proven challenging. Here, we demonstrated that iPSC-derived macrophages (iMacs) with ablated SIRPa yield a superior antitumor effect in conjunction with cancer-targeted antibodies (Ab) or chimeric antigen receptor (CAR) against a variety of CD47-expressing tumors in vitro. Moreover, SIRPA-KO protected macrophages from Ab- or CAR-driven exhaustion, allowing for efficient phagocytosis of tumors after multiple rounds of cancer re-challenges. Ablation of SIRPa in iMacs improved survival of mice grafted ovarian carcinoma and treated with anti-HER2 Abs, while anti-GD2 CAR iMacs with KO SIRPA demonstrated reduction of initial tumor burden in mice with metastatic neuroblastoma xenograft. Overall, our studies support the feasibility of using the iPSC platform to generate SIRPα-ablated iMacs that are resistant to CD47-mediated inhibition for therapeutic applications.
Project description:CD200R is an immune checkpoint receptor of the IgG family that is primarily expressed on cells of the myeloid lineage. In vivo studies with knockout mice of either the receptor or its ligand, CD200, have demonstrated that it is an inhibitory receptor capable of negatively regulating immune responses. Previous work using agonistic antibodies to mouse CD200R showed inhibition of mast cell activation in multiple preclinical models of autoimmune diseases. We developed an agonistic antibody to the human CD200 receptor to downregulate the immune system human inflammatory conditions. Ucenprubart, is a humanized IgG4 monoclonal antibody that binds and agonizes human CD200R to suppress cellular activity in CD200R-expressing cells.The antibody was engineered to have desired properties for agonism and cross-reactivity to cyno CD200R. In vivo the antibody demonstrated efficacy in a humanized mouse model of contact hypersensitivity as well as passive cutaneous anaphylaxis in cynomolgus monkeys.
Project description:Epigenetic regulation plays a crucial role in the pathogenesis of autoimmune diseases such as inflammatory arthritis. DNA hypomethylating agents, such as decitabine (DAC), have been shown to dampen inflammation and restore immune homeostasis. In the present study, we demonstrate that DAC elicits potent anti-inflammatory effects and attenuates disease symptoms in several animal models of arthritis.
Project description:A computational platform, the Boolean network explorer (BoNE), has recently been developed to infuse AI-enhanced precision into drug discovery; it enables querying and navigating invariant Boolean Implication Networks of disease maps for prioritizing high-value targets. Here we used BoNE to query an Inflammatory Bowel Disease (IBD)-map and prioritize two nuclear receptors, PPARa/g. Balanced agonism of PPARa/g was predicted to impact macrophage processes, ameliorate colitis in network-prioritized animal models, ‘reset’ the gene expression network from disease to health, and achieve a favorable therapeutic index that tracked other FDA-approved targets. Predictions were validated using a balanced and potent PPARa/g-dual agonist (PAR5359) in two pre-clinical murine models, i.e., Citrobacter rodentium-induced infectious colitis and DSS-induced colitis. Mechanistically, we show that such balanced dual agonism promotes bacterial clearance more efficiently than individual agonists both in vivo and in vitro; PPARa is required and its agonism is sufficient to induce the pro-inflammatory cytokines and cellular ROS, which are essential for bacterial clearance and immunity, whereas PPARg-agonism blunts these responses, delays microbial clearance and induces the anti-inflammatory cytokine, IL10. Balanced agonism achieved controlled inflammation while protecting the gut barrier and ‘reversal’ of the transcriptomic network. Furthermore, dual agonism effectively reversed the defective bacterial clearance observed in PBMCs derived from IBD patients. These findings not only deliver a macrophage modulator for use as barrier-protective therapy in IBD, but also highlight the potential of BoNE to accelerate and enhance the precision of drug discovery.
Project description:Immune checkpoint inhibitors (ICIs) are associated with immune-related adverse events (irAEs) which are more severe when ICIs are used in combination. A mouse model was developed to elucidate the molecular mechanisms of immune-related hepatitis, one of the common irAEs associated with ICIs. Molecular profiling by single cell RNA sequencing was performed on Pdcd1-/- mice treated with anti-CTLA4 and/or the IDO1 inhibitor epacadostat or a 4-1BB agonistic antibody. ICI combination-induced hepatitis and 4-1BB agonist-mediated hepatitis share similar features yet maintain distinct immune signatures. Both were characterized by an expansion of activated T cells. Single-cell transcriptomics revealed that the hepatitis induced by combination ICIs is associated with a robust immune activation signature in all subtypes of T cells and T helper 1 skewing. Expression profiling revealed a central role for IFNγ and liver monocyte-derived macrophages in promoting a pro-inflammatory T-cell response to ICI combination and 4-1BB agonism.
Project description:Immune checkpoint inhibitors (ICIs) are associated with immune-related adverse events (irAEs) which are more severe when ICIs are used in combination. A mouse model was developed to elucidate the molecular mechanisms of immune-related hepatitis, one of the common irAEs associated with ICIs. Molecular profiling by single cell RNA sequencing was performed on Pdcd1-/- mice treated with anti-CTLA4 and/or the IDO1 inhibitor epacadostat or a 4-1BB agonistic antibody. ICI combination-induced hepatitis and 4-1BB agonist-mediated hepatitis share similar features yet maintain distinct immune signatures. Both were characterized by an expansion of activated T cells. Single-cell transcriptomics revealed that the hepatitis induced by combination ICIs is associated with a robust immune activation signature in all subtypes of T cells and T helper 1 skewing. Expression profiling revealed a central role for IFNγ and liver monocyte-derived macrophages in promoting a pro-inflammatory T-cell response to ICI combination and 4-1BB agonism.