Metformin induces ZFP36 by mTORC1 inhibition in cervical cancer-derived cell lines.

BACKGROUND: Metformin, a widely prescribed antidiabetic drug, has shown several promising effects for cancer treatment. These effects have been shown to be mediated by dual modulation of the AMPK-mTORC1 axis, where AMPK acts upstream of mTORC1 to decrease its activity. Nevertheless, alternative pathways have been recently discovered suggesting that metformin can act through of different targets regulation. METHODS: We performed a transcriptome screening analysis using HeLa xenograft tumors generated in NOD-SCID mice treated with or without metformin to examine genes regulated by metformin. Western Blot analysis, Immunohistochemical staining, and RT-qPCR were used to confirm alterations in gene expression. The TNMplot and GEPIA2 platform were used for in silico analysis of genes found up-regulated by metformin, in cervical cancer patients. We performed an AMPK knock-down using AMPK-targeted siRNAs and mTOR inhibition with rapamycin to investigate the molecular mechanisms underlying the effect of metformin in cervical cancer cell lines. RESULTS: We shown that metformin decreases tumor growth and increased the expression of a group of antitumoral genes involved in DNA-binding transcription activator activity, hormonal response, and Dcp1-Dcp2 mRNA-decapping complex. We demonstrated that ZFP36 could act as a new molecular target increased by metformin. mTORC1 inhibition using rapamycin induces ZFP36 expression, which could suggest that metformin increases ZFP36 expression and requires mTORC1 inhibition for such effect. Surprisingly, in HeLa cells AMPK inhibition did not affect ZFP36 expression, suggesting that additional signal transducers related to suppressing mTORC1 activity, could be involved. CONCLUSIONS: These results highlight the importance of ZFP36 activation in response to metformin treatment involving mTORC1 inhibition.

Exploring dose-response variability and relative severity assessment in STZ-induced diabetes male NSG mice.

NSG mice are among the most immunodeficient mouse model being used in various scientific branches. In diabetelogical research diabetic NSG mice are an important asset as a xenotransplantation model for human pancreatic islets or pluripotent stem cell-derived islets. The treatment with the beta cell toxin streptozotocin is the standard procedure for triggering a chemically induced diabetes. Surprisingly, little data has been published about the reproducibility, stress and animal suffering in these NSG mice during diabetes induction. The 3R rules, however, are a constant reminder that existing methods can be further refined to minimize suffering. In this pilot study the dose-response relationship of STZ in male NSG mice was investigated and additionally animal suffering was charted by applying the novel 'Relative Severity Assessment' algorithm. By this we successfully explored an STZ dose that reliably induced diabetes while reduced stress and pain to the animals to a minimum using evidence-based and objective parameters rather than criteria that might be influenced by human bias.

The Parasite-Derived Peptide, FhHDM-1, Selectively Modulates miRNA Expression in ß-Cells to Prevent Apoptotic Pathways Induced by Proinflammatory Cytokines.

We have previously identified a parasite-derived peptide, FhHDM-1, that prevented the progression of diabetes in nonobese diabetic (NOD) mice. Disease prevention was mediated by the activation of the PI3K/Akt pathway to promote ß-cell survival and metabolism without inducing proliferation. To determine the molecular mechanisms driving the antidiabetogenic effects of FhHDM-1, miRNA:mRNA interactions and in silico predictions of the gene networks were characterised in ß-cells, which were exposed to the proinflammatory cytokines that mediate ß-cell destruction in Type 1 diabetes (T1D), in the presence and absence of FhHDM-1. The predicted gene targets of miRNAs differentially regulated by FhHDM-1 mapped to the biological pathways that regulate ß-cell biology. Six miRNAs were identified as important nodes in the regulation of PI3K/Akt signaling. Additionally, IGF-2 was identified as a miRNA gene target that mediated the beneficial effects of FhHDM-1 on ß-cells. The findings provide a putative mechanism by which FhHDM-1 positively impacts ß-cells to permanently prevent diabetes. As ß-cell death/dysfunction underlies diabetes development, FhHDM-1 opens new therapeutic avenues.

rhIL-7-hyFc, a long-acting interleukin-7, improves efficacy of CAR-T cell therapy in solid tumors.

BACKGROUND: Chimeric antigen receptor T-cell (CAR-T) therapy has achieved remarkable remission in patients with B-cell malignancies. However, its efficacy in treating solid tumors remains limited. Here, we investigated a combination therapy approach using an engineered long-acting interleukin (IL)-7 (rhIL-7-hyFc or NT-I7) and CAR-T cells targeting three antigens, glypican-2 (GPC2), glypican-3 (GPC3), and mesothelin (MSLN), against multiple solid tumor types including liver cancer, neuroblastoma, ovarian cancer, and pancreatic cancer in mice. METHODS: CAR-T cells targeting GPC2, GPC3, and MSLN were used in combination with NT-I7 to assess the anticancer activity. Xenograft tumor models, including the liver cancer orthotopic model, were established using NOD scid gamma mice engrafted with cell lines derived from hepatocellular carcinoma, neuroblastoma, ovarian cancer, and pancreatic cancer. The mice were monitored by bioluminescence in vivo tumor imaging and tumor volume measurement using a caliper. Immunophenotyping of CAR-T cells on NT-I7 stimulation was evaluated for memory markers, exhaust markers, and T-cell signaling molecules by flow cytometry and western blotting. RESULTS: Compared with the IL-2 combination, preclinical evaluation of NT-I7 exhibited regression of solid tumors via enhanced occupancy of CD4+ CAR-T, improved T-cell expansion, reduced exhaustion markers (programmed cell death protein 1 or PD-1 and lymphocyte-activation gene 3 or LAG-3) expression, and increased generation of stem cell-like memory CAR-T cells. The STAT5 pathway was demonstrated to be downstream of NT-I7 signaling, mediated by increased expression of the IL-7 receptor expression in CAR-T cells. Furthermore, CAR-T cells improved efficacy against tumors with low antigen density when combined with NT-I7 in mice, presenting an avenue for patients with heterogeneous antigenic profiles. CONCLUSION: This study provides a rationale for NT-I7 plus CAR-T cell combination therapy for solid tumors in humans.

CAR T-cells targeting FGFR4 and CD276 simultaneously show potent antitumor effect against childhood rhabdomyosarcoma.

Chimeric antigen receptor (CAR) T-cells targeting Fibroblast Growth Factor Receptor 4 (FGFR4), a highly expressed surface tyrosine receptor in rhabdomyosarcoma (RMS), are already in the clinical phase of development, but tumour heterogeneity and suboptimal activation might hamper their potency. Here we report an optimization strategy of the co-stimulatory and targeting properties of a FGFR4 CAR. We replace the CD8 hinge and transmembrane domain and the 4-1BB co-stimulatory domain with those of CD28. The resulting CARs display enhanced anti-tumor activity in several RMS xenograft models except for an aggressive tumour cell line, RMS559. By searching for a direct target of the RMS core-regulatory transcription factor MYOD1, we identify another surface protein, CD276, as a potential target. Bicistronic CARs (BiCisCAR) targeting both FGFR4 and CD276, containing two distinct co-stimulatory domains, have superior prolonged persistent and invigorated anti-tumor activities compared to the optimized FGFR4-specific CAR and the other BiCisCAR with the same 4-1BB co-stimulatory domain. Our study thus lays down the proof-of-principle for a CAR T-cell therapy targeting both FGFR4 and CD276 in RMS.

Orchestrating NK and T cells via tri-specific nano-antibodies for synergistic antitumor immunity.

The functions of natural killer (NK) and T cells in innate and adaptive immunity, as well as their functions in tumor eradication, are complementary and intertwined. Here we show that utilization of multi-specific antibodies or nano-antibodies capable of simultaneously targeting both NK and T cells could be a valuable approach in cancer immunotherapy. Here, we introduce a tri-specific Nano-Antibody (Tri-NAb), generated by immobilizing three types of monoclonal antibodies (mAbs), using an optimized albumin/polyester composite nanoparticle conjugated with anti-Fc antibody. This Tri-NAb, targeting PDL1, 4-1BB, and NKG2A (or TIGIT) simultaneously, effectively binds to NK and CD8+ T cells, triggering their activation and proliferation, while facilitating their interaction with tumor cells, thereby inducing efficient tumor killing. Importantly, the antitumor efficacy of Tri-NAb is validated in multiple models, including patient-derived tumor organoids and humanized mice, highlighting the translational potential of NK and T cell co-targeting.

Alkynyl nicotinamides show antileukemic activity in drug-resistant acute myeloid leukemia.

Activating mutations of FLT3 contribute to deregulated hematopoietic stem and progenitor cell (HSC/Ps) growth and survival in patients with acute myeloid leukemia (AML), leading to poor overall survival. AML patients treated with investigational drugs targeting mutant FLT3, including Quizartinib and Crenolanib, develop resistance to these drugs. Development of resistance is largely due to acquisition of cooccurring mutations and activation of additional survival pathways, as well as emergence of additional FLT3 mutations. Despite the high prevalence of FLT3 mutations and their clinical significance in AML, there are few targeted therapeutic options available. We have identified 2 novel nicotinamide-based FLT3 inhibitors (HSN608 and HSN748) that target FLT3 mutations at subnanomolar concentrations and are potently effective against drug-resistant secondary mutations of FLT3. These compounds show antileukemic activity against FLT3ITD in drug-resistant AML, relapsed/refractory AML, and in AML bearing a combination of epigenetic mutations of TET2 along with FLT3ITD. We demonstrate that HSN748 outperformed the FDA-approved FLT3 inhibitor Gilteritinib in terms of inhibitory activity against FLT3ITD in vivo.

CXCL5 impedes CD8+ T cell immunity by upregulating PD-L1 expression in lung cancer via PXN/AKT signaling phosphorylation and neutrophil chemotaxis.

BACKGROUND: Lung cancer remains one of the most prevalent cancer types worldwide, with a high mortality rate. Upregulation of programmed cell death protein 1 (PD-1) and its ligand (PD-L1) may represent a key mechanism for evading immune surveillance. Immune checkpoint blockade (ICB) antibodies against PD-1 or PD-L1 are therefore widely used to treat patients with lung cancer. However, the mechanisms by which lung cancer and neutrophils in the microenvironment sustain PD-L1 expression and impart stronger inhibition of CD8+ T cell function remain unclear. METHODS: We investigated the role and underlying mechanism by which PD-L1+ lung cancer and PD-L1+ neutrophils impede the function of CD8+ T cells through magnetic bead cell sorting, quantitative real-time polymerase chain reaction (RT-PCR), western blotting, enzyme-linked immunosorbent assays, confocal immunofluorescence, gene silencing, flow cytometry, etc. In vivo efficacy and safety studies were conducted using (Non-obeseDiabetes/severe combined immune deficiency) SCID/NOD mice. Additionally, we collected clinical and prognostic data from 208 patients who underwent curative lung cancer resection between 2017 and 2018. RESULTS: We demonstrated that C-X-C motif chemokine ligand 5 (CXCL5) is markedly overexpressed in lung cancer cells and is positively correlated with a poor prognosis in patients with lung cancer. Mechanistically, CXCL5 activates the phosphorylation of the Paxillin/AKT signaling cascade, leading to upregulation of PD-L1 expression and the formation of a positive feedback loop. Moreover, CXCL5 attracts neutrophils, compromising CD8+ T cell-dependent antitumor immunity. These PD-L1+ neutrophils aggravate CD8+ T cell exhaustion following lung cancer domestication. Combined treatment with anti-CXCL5 and anti-PD-L1 antibodies significantly inhibits tumor growth in vivo. CONCLUSIONS: Our findings collectively demonstrate that CXCL5 promotes immune escape through PD-L1 upregulation in lung cancer and neutrophils chemotaxis through autocrine and paracrine mechanisms. CXCL5 may serve as a potential therapeutic target in synergy with ICBs in lung cancer immunotherapy.

T-cell responses in colorectal peritoneal metastases are recapitulated in a humanized immune system mouse model.

Background: The occurrence of peritoneal metastasis (PM) in patients with colorectal cancer (CRC) has a dismal prognosis. There is often limited response to systemic- and immunotherapy, even in microsatellite unstable (MSI) CRC. To overcome therapy resistance, it is critical to understand local immune environment in the peritoneal cavity, and to develop models to study anti-tumor immune responses. Here, we defined the peritoneal immune system (PerIS) in PM-CRC patients and evaluate the pre-clinical potential of a humanized immune system (HIS) mouse model for PM-CRC. Methods: We studied the human PerIS in PM-CRC patients (n=20; MSS 19/20; 95%) and in healthy controls (n=3). HIS mice (NODscid gamma background; n=18) were generated, followed by intraperitoneal injection of either saline (HIS control; n=3) or human MSS/MSI CRC cell lines HUTU80, MDST8 and HCT116 (HIS-PM, n=15). Immune cells in peritoneal fluid and peritoneal tumors were analyzed using cytometry by time of flight (CyTOF). Results: The human and HIS mouse homeostatic PerIS was equally populated by NK cells and CD4+- and CD8+ T cells, however differences were observed in macrophage and B cell abundance. In HIS mice, successful peritoneal engraftment of both MSI and MSS tumors was observed (15/15; 100%). Both in human PM-CRC and in the HIS mouse PM-CRC model, we observed that MSS PM-CRC triggered a CD4+ Treg response in the PerIS, while MSI PM-CRC drives CD8+ TEMs responses. Conclusion: In conclusion, T cell responses in PM-CRC in HIS mice mirror those in human PM-CRC, making this model suitable to study antitumor T cell responses in PM-CRC.

Generation of antitumor chimeric antigen receptors incorporating T cell signaling motifs.

Chimeric antigen receptor (CAR) T cells have been used to successfully treat various blood cancers, but adverse effects have limited their potential. Here, we developed chimeric adaptor proteins (CAPs) and CAR tyrosine kinases (CAR-TKs) in which the intracellular ζ T cell receptor (TCRζ) chain was replaced with intracellular protein domains to stimulate signaling downstream of the TCRζ chain. CAPs contain adaptor domains and the kinase domain of ZAP70, whereas CAR-TKs contain only ZAP70 domains. We hypothesized that CAPs and CAR-TKs would be more potent than CARs because they would bypass both the steps that define the signaling threshold of TCRζ and the inhibitory regulation of upstream molecules. CAPs were too potent and exhibited high tonic signaling in vitro. In contrast, CAR-TKs exhibited high antitumor efficacy and significantly enhanced long-term tumor clearance in leukemia-bearing NSG mice as compared with the conventional CD19-28ζ-CAR-T cells. CAR-TKs were activated in a manner independent of the kinase Lck and displayed slower phosphorylation kinetics and prolonged signaling compared with the 28ζ-CAR. Lck inhibition attenuated CAR-TK cell exhaustion and improved long-term function. The distinct signaling properties of CAR-TKs may therefore be harnessed to improve the in vivo efficacy of T cells engineered to express an antitumor chimeric receptor.

Modeling HBV Infection and Therapy in Immunodeficient NOD-Rag1-/-IL2RgammaC-null (NRG) Fumarylacetoacetate Hydrolase (FAH) Knockout Mice with Human Chimeric Liver.

Chimeric mouse models with a humanized liver (Hu-HEP mice) provide a unique tool to study human hepatotropic virus diseases, including viral infection, viral pathogenesis, and anti-viral therapy. Here, we describe a detailed protocol for studying hepatitis B infection in NRG-derived fumarylacetoacetate hydrolase (FAH) knockout mice repopulated with human hepatocytes (FRG-Hu HEP mice). The procedures include (1) maintenance and genotyping of the FRG mice, (2) intrasplenic injection of primary human hepatocytes (PHH), (3) 2-(2-nitro-4-fluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC) drug reduction cycling to improve human hepatocyte repopulation, (4) human albumin detection, and (5) HBV infection and detection. The method is simple and allows for highly reproducible generation of FRG-Hu HEP mice for HBV infection and therapy investigations.

[Establishment of a humanized mouse model of HIV-1 infection and quantification of integrated HIV proviral DNA in vivo].

In recent years, virological, pathological, and immunological studies need to be carried out for the emerging anti-human immunodeficiency virus (HIV) therapies such as gene therapy, broadly neutralizing antibodies, and the derived chimeric antigen receptor (CAR)-T immunotherapy, which necessitates suitable, simple, and inexpensive small-animal models and methods for accurate quantification of the viral genome in the HIV-1 infected. In our research, the HIV-∆ENV-Jurkat-EGFP-mCherry cell line was engineered through the infection with a dual-labelled HIV pseudovirus. A nested quantitative PCR (nested-qPCR) method with the cellular genome as the integrated standard was established for the quantification of HIV proviral copies. We administered intravenous injections of healthy human peripheral blood mononuclear cell (PBMC) into NOD/Prkdcscid/IL2rgnull (NPG) mice. To verify engraftment kinetics, we analyzed the percentages of hCD45+, hCD3+, hCD4+, and hCD8+ cells in the peripheral blood of hu-PBMC-NPG mice. To evaluate HIV-1 infection in hu-PBMC-NPG mice, we inoculated these mice with HIV NL4-3-NanoLuc by intraperitoneal (IP) injection. We then monitored the luciferase expression by the small animal imaging system and measured the viral load in the spleen by qPCR. The infiltration of human PBMCs in mice was detected 3-5 weeks after intravenous injection, and the percentage of hCD45 in humanized mouse PBMCs were more than 25% five weeks after IP inoculation. The expression of the virus-associated luciferase protein was detected by luciferase imaging 27 days post infection. Moreover, the viral total DNA, RNA, and proviral DNA copies reached 18 000 copies/106 cells, 15 000 copies/µg RNA, and 15 000 copies/106 cells, respectively, in the mouse spleen. Taken together, we reported a convenient method for building a simple humanized mouse model of HuPBMC-NPG/severe combined immunodeficiency (SCID) by intravenous injection with hu-PBMCs without advanced surgical skills and irradiation. Furthermore, we established a convenient method for the efficient determination of proviral DNA to assess HIV replication in vivo, viral reservoir sizes, and efficacy of novel anti-HIV therapies including CAR-T immunotherapy and gene therapy.

Bromodomain Protein Inhibition Protects ß-Cells from Cytokine-Induced Death and Dysfunction via Antagonism of NF-κB Pathway.

Cytokine-induced ß-cell apoptosis is a major pathogenic mechanism in type 1 diabetes (T1D). Despite significant advances in understanding its underlying mechanisms, few drugs have been translated to protect ß-cells in T1D. Epigenetic modulators such as bromodomain-containing BET (bromo- and extra-terminal) proteins are important regulators of immune responses. Pre-clinical studies have demonstrated a protective effect of BET inhibitors in an NOD (non-obese diabetes) mouse model of T1D. However, the effect of BET protein inhibition on ß-cell function in response to cytokines is unknown. Here, we demonstrate that I-BET, a BET protein inhibitor, protected ß-cells from cytokine-induced dysfunction and death. In vivo administration of I-BET to mice exposed to low-dose STZ (streptozotocin), a model of T1D, significantly reduced ß-cell apoptosis, suggesting a cytoprotective function. Mechanistically, I-BET treatment inhibited cytokine-induced NF-kB signaling and enhanced FOXO1-mediated anti-oxidant response in ß-cells. RNA-Seq analysis revealed that I-BET treatment also suppressed pathways involved in apoptosis while maintaining the expression of genes critical for ß-cell function, such as Pdx1 and Ins1. Taken together, this study demonstrates that I-BET is effective in protecting ß-cells from cytokine-induced dysfunction and apoptosis, and targeting BET proteins could have potential therapeutic value in preserving ß-cell functional mass in T1D.

Beta cells deficient for Renalase counteract autoimmunity by shaping natural killer cell activity.

Type 1 diabetes (T1D) arises from autoimmune-mediated destruction of insulin-producing pancreatic beta cells. Recent advancements in the technology of generating pancreatic beta cells from human pluripotent stem cells (SC-beta cells) have facilitated the exploration of cell replacement therapies for treating T1D. However, the persistent threat of autoimmunity poses a significant challenge to the survival of transplanted SC-beta cells. Genetic engineering is a promising approach to enhance immune resistance of beta cells as we previously showed by inactivating the Renalase (Rnls) gene. Here, we demonstrate that Rnls loss of function in beta cells shapes autoimmunity by mediating a regulatory natural killer (NK) cell phenotype important for the induction of tolerogenic antigen-presenting cells. Rnls-deficient beta cells mediate cell-cell contact-independent induction of hallmark anti-inflammatory cytokine Tgfß1 in NK cells. In addition, surface expression of regulatory NK immune checkpoints CD47 and Ceacam1 is markedly elevated on beta cells deficient for Rnls. Altered glucose metabolism in Rnls mutant beta cells is involved in the upregulation of CD47 surface expression. These findings are crucial to better understand how genetically engineered beta cells shape autoimmunity, giving valuable insights for future therapeutic advancements to treat and cure T1D.

MiR-23b-3p alleviates Sjögren's syndrome by targeting SOX6 and inhibiting the NF-κB signaling.

OBJECTIVE: MicroRNA-23b-3p has been demonstrated to act as a safeguard against several autoimmune diseases. However, its role in Sjögren's syndrome (SS) remains unclear. METHODS: In order to investigate its role in SS, we administered agomiR-23b-3p or agomiR-NC to non-obese diabetic (NOD) mice via tail vein weekly for 6 weeks. The study examined the saliva flow rate, histological changes in submandibular glands, and levels of autoantibodies. Additionally, the levels of several cytokines, cell apoptosis, and NF-κB signaling were evaluated. The protective effect of miR-23b-3p was confirmed in a cell model. RESULTS: The results demonstrated that miR-23b-3p overexpression improved salivary flow rates, inhibited lymphocyte infiltration, reduced cytokine levels, and suppressed cell apoptosis in NOD mice. Moreover, NF-κB signaling was inactivated following miR-23b-3p overexpression. In a cellular model of SS, overexpression of miR-23b-3p protected submandibular gland epithelial cells exposed to IFN-γ against apoptosis and inflammation by targeting SOX6. CONCLUSIONS: The study concludes that miR-23b-3p alleviates SS by targeting SOX6 and inhibiting the NF-κB signaling pathway. The miR-23b-3p/SOX6 axis represents a promising avenue for the development of novel therapeutic strategies for SS.

Bone Marrow Mesenchymal Stem Cells Promote Ovarian Cancer Cell Proliferation via Cytokine Interactions.

Bone marrow mesenchymal stem cells (BMSCs) are key players in promoting ovarian cancer cell proliferation, orchestrated by the dynamic interplay between cytokines and their interactions with immune cells; however, the intricate crosstalk among BMSCs and cytokines has not yet been elucidated. Here, we aimed to investigate interactions between BMSCs and ovarian cancer cells. We established BMSCs with a characterized morphology, surface marker expression, and tri-lineage differentiation potential. Ovarian cancer cells (SKOV3) cultured with conditioned medium from BMSCs showed increased migration, invasion, and colony formation, indicating the role of the tumor microenvironment in influencing cancer cell behavior. BMSCs promoted SKOV3 tumorigenesis in nonobese diabetic/severe combined immunodeficiency mice, increasing tumor growth. The co-injection of BMSCs increased the phosphorylation of p38 MAPK and GSK-3ß in SKOV3 tumors. Co-culturing SKOV3 cells with BMSCs led to an increase in the expression of cytokines, especially MCP-1 and IL-6. These findings highlight the influence of BMSCs on ovarian cancer cell behavior and the potential involvement of specific cytokines in mediating these effects. Understanding these mechanisms will highlight potential therapeutic avenues that may halt ovarian cancer progression.

Human iPSC-derived CD4+ Treg-like cells engineered with chimeric antigen receptors control GvHD in a xenograft model.

CD4+ T cells induced from human iPSCs (iCD4+ T cells) offer a therapeutic opportunity for overcoming immune pathologies arising from hematopoietic stem cell transplantation. However, most iCD4+ T cells are conventional helper T cells, which secrete inflammatory cytokines. We induced high-level expression of FOXP3, a master transcription factor of regulatory T cells, in iCD4+ T cells. Human iPSC-derived, FOXP3-induced CD4+ T (iCD4+ Treg-like) cells did not secrete inflammatory cytokines upon activation. Moreover, they showed demethylation of the Treg-specific demethylation region, suggesting successful conversion to immunosuppressive iCD4+ Treg-like cells. We further assessed these iCD4+ Treg-like cells for CAR-mediated immunosuppressive ability. HLA-A2 CAR-transduced iCD4+ Treg-like cells inhibited CD8+ cytotoxic T cell (CTL) division in a mixed lymphocyte reaction assay with A2+ allogeneic CTLs and suppressed xenogeneic graft-versus-host disease (GVHD) in NSG mice treated with A2+ human PBMCs. In most cases, these cells suppressed the xenogeneic GvHD progression as much as natural CD25+CD127- Tregs did.

IFNγ causes mitochondrial dysfunction and oxidative stress in myositis.

Idiopathic inflammatory myopathies (IIMs) are severe autoimmune diseases with poorly understood pathogenesis and unmet medical needs. Here, we examine the role of interferon γ (IFNγ) using NOD female mice deficient in the inducible T cell co-stimulator (Icos), which have previously been shown to develop spontaneous IFNγ-driven myositis mimicking human disease. Using muscle proteomic and spatial transcriptomic analyses we reveal profound myofiber metabolic dysregulation in these mice. In addition, we report muscle mitochondrial abnormalities and oxidative stress in diseased mice. Supporting a pathogenic role for oxidative stress, treatment with a reactive oxygen species (ROS) buffer compound alleviated myositis, preserved muscle mitochondrial ultrastructure and respiration, and reduced inflammation. Mitochondrial anomalies and oxidative stress were diminished following anti-IFNγ treatment. Further transcriptomic analysis in IIMs patients and human myoblast in vitro studies supported the link between IFNγ and mitochondrial dysfunction observed in mice. These results suggest that mitochondrial dysfunction, ROS and inflammation are interconnected in a self-maintenance loop, opening perspectives for mitochondria therapy and/or ROS targeting drugs in myositis.

Pannexin-1 expression in tumor cells correlates with colon cancer progression and survival.

AIMS: Pannexin-1 (PANX1) is a hemichannel that releases ATP upon opening, initiating inflammation, cell proliferation, and migration. However, the role of PANX1 channels in colon cancer remains poorly understood, thus constituting the focus of this study. MAIN METHODS: PANX1 mRNA expression was analyzed using multiple cancer databases. PANX1 protein expression and distribution were evaluated by immunohistochemistry on primary tumor tissue and non-tumor colonic mucosa from colon cancer patients. PANX1 inhibitors (probenecid or 10Panx) were used to assess colon cancer cell lines viability. To study the role of PANX1 in vivo, a subcutaneous xenograft model using HCT116 cells was performed in BALB/c NOD/SCID immunodeficient mice to evaluate tumor growth under PANX1 inhibition using probenecid. KEY FINDINGS: PANX1 mRNA was upregulated in colon cancer tissue compared to non-tumor colonic mucosa. Elevated PANX1 mRNA expression in tumors correlated with worse disease-free survival. PANX1 protein abundance was increased on tumor cells compared to epithelial cells in paired samples, in a cancer stage-dependent manner. In vitro and in vivo experiments indicated that blocking PANX1 reduced cell viability and tumor growth. SIGNIFICANCE: PANX1 can be used as a biomarker of colon cancer progression and blocking PANX1 channel opening could be used as a potential therapeutic strategy against this disease.

Soluble antigen arrays provide increased efficacy and safety over free peptides for tolerogenic immunotherapy.

Autoantigen-specific immunotherapy using peptides offers a more targeted approach to treat autoimmune diseases, but clinical implementation has been challenging. We previously showed that multivalent delivery of peptides as soluble antigen arrays (SAgAs) efficiently protects against spontaneous autoimmune diabetes in the non-obese diabetic (NOD) mouse model. Here, we compared the efficacy, safety, and mechanisms of action of SAgAs versus free peptides. SAgAs, but not their corresponding free peptides at equivalent doses, efficiently prevented the development of diabetes. SAgAs increased the frequency of regulatory T cells among peptide-specific T cells or induce their anergy/exhaustion or deletion, depending on the type of SAgA used (hydrolysable (hSAgA) and non-hydrolysable 'click' SAgA (cSAgA)) and duration of treatment, whereas their corresponding free peptides induced a more effector phenotype following delayed clonal expansion. Over time, the peptides induced an IgE-independent anaphylactic reaction, the incidence of which was significantly delayed when peptides were in SAgA form rather than in free form. Moreover, the N-terminal modification of peptides with aminooxy or alkyne linkers, which was needed for grafting onto hyaluronic acid to make hSAgA or cSAgA variants, respectively, influenced their stimulatory potency and safety, with alkyne-functionalized peptides being more potent and less anaphylactogenic than aminooxy-functionalized peptides. Immunologic anaphylaxis occurred in NOD mice in a dose-dependent manner but not in C57BL/6 or BALB/c mice; however, its incidence did not correlate with the level of anti-peptide antibodies. We provide evidence that SAgAs significantly improve the efficacy of peptides to induce tolerance and prevent autoimmune diabetes while at the same time reducing their anaphylactogenic potential.