Humanized Mouse Model Research Articles

Preclinical pharmacology characterization of HX009, a novel PD1 x CD47 Bi-specific antibody.

Certain immune-checkpoint inhibitors have a narrow therapeutic window (TW) as cancer therapeutics, and engineered dual-/multi-targeting agents could potentially widen the TW to bring true clinical benefits. We report a new rationally-designed bispecific-antibody (BsAb), HX009, simultaneously targeting PD1 and CD47 to improve both the efficacy and safety over the respective single-targeting agents by grafting the extracellular domain of SIRPα onto the parental anti-PD1-monoclonal antibody, HX008. This resulted in an IgG4-based "2 × 2" symmetric structure but with an intentionally-reduced CD47-binding affinity, suggesting a novel candidate cancer immunotherapy. Specifically, HX009 has binding affinity constant of 8.951 × 10-9M for human PD1 and 2.557 × 10-8M for human CD47, respectively, where the CD47 binding is significantly weaker as compared to the binding affinity of HX008 to PD1 as well as the binding affinity of SIRPα-Fc to CD47, leading to little binding to RBCs and platelets and is contrasting to many CD47-agents in development. However, HX009 effectively and simultaneously binds to the PD1 and CD47 on PD1+CD47+ T-cells via cis-binding and elicits enhanced T cell activation compared to the parental HX008. HX009 caused little cytokine-release in human peripheral blood mononuclear cells. HX009 cross-species binds to cynomolgus monkey PD1/CD47 but not to rodents, making cynomolgus monkeys the choice of species to investigate the pharmacokinetics (PK) and toxicology of HX009. HX009's anti-tumor activities were confirmed in several humanized preclinical mouse models by determining either its anti-PD1 (humanized hu-CD47-MC38 models) or anti-CD47 (HuT-102 lymphoma CDX and three PDX-AML models) functions, although limited available humanized models have hindered broadly demonstration of enhanced anti-tumor activities contributed from the dual targeting of the BsAb. The expanded DLBCL-PDX trial data suggested that both EBV-status and OX40 expression could potentially be two positive predictors for response to HX009. An intravenous (IV) infusion PK study in cynomolgus monkey revealed its largely vasculature distribution, terminal half-life (T1/2) of ~ 50h, and dose-proportional exposure without accumulation. The anti-drug antibody (ADA) was observed in all monkeys as expected, affecting the PK parameters of repeated administration. The IV single-dose toxicology study with a 14-day observation revealed a maximum tolerated dose of 150mg/kg, while the repeated-dose (once weekly for 4weeks, 5 doses in total) study showed a highest non-severely toxic dose (HNSTD) of 15mg/kg. The desired preclinical PK and safety profiles, along with its antitumor activity, support HX009's candidacy for its clinical development.

Pathophysiology and preclinical relevance of experimental graft-versus-host disease in humanized mice.

Graft-versus-host disease (GVHD) is a life-threatening complication of allogeneic hematopoietic cell transplantations (allo-HCT) used for the treatment of hematological malignancies and other blood-related disorders. Until recently, the discovery of actionable molecular targets to treat GVHD and their preclinical testing was almost exclusively based on modeling allo-HCT in mice by transplanting bone marrow and splenocytes from donor mice into MHC-mismatched recipient animals. However, due to fundamental differences between human and mouse immunology, the translation of these molecular targets into the clinic can be limited. Therefore, humanized mouse models of GVHD were developed to circumvent this limitation. In these models, following the transplantation of human peripheral blood mononuclear cells (PBMCs) into immunodeficient mice, T cells recognize and attack mouse organs, inducing GVHD. Thereby, humanized mice provide a platform for the evaluation of the effects of candidate therapies on GVHD mediated by human immune cells in vivo. Understanding the pathophysiology of this xenogeneic GVHD is therefore crucial for the design and interpretation of experiments performed with this model. In this article, we comprehensively review the cellular and molecular mechanisms governing GVHD in the most commonly used model of xenogeneic GVHD: PBMC-engrafted NOD/LtSz-PrkdcscidIL2rγtm1Wjl (NSG) mice. By re-analyzing public sequencing data, we also show that the clonal expansion and the transcriptional program of T cells in humanized mice closely reflect those in humans. Finally, we highlight the strengths and limitations of this model, as well as arguments in favor of its biological relevance for studying T-cell reactions against healthy tissues or cancer cells.

Abstract 4122301: The Role of Hepatic CDS2 in Phosphatidylinositol Homeostasis and Lipid Metabolism

Background: Recent studies in both human genetics and mouse models have highlighted the significance of phosphatidylinositol (PI) in the progression of fatty liver disease (FLD). Despite this, the precise mechanisms underlying PI's role remain elusive. Aims: This study aimed to elucidate the involvement of PI in FLD by disrupting hepatic PI biosynthesis through modulation of CDP-diacylglycerol synthase 2 (CDS2) expression, the primary enzyme in PI biosynthesis (A). Methods: We generated liver-specific knockouts of CDS2 and SCAP (SREBP cleavage-activating protein) using adeno-associated virus (AAV) expressing sgRNA against each gene. Phospholipid species were analyzed and quantified by LC/MS. Results: CDS2 liver-specific knockout mice (B, C) exhibited a pronounced development of fatty liver, characterized by elevated triglyceride and cholesterol levels (C). Notably, liver PI levels were significantly reduced in CDS2 knockout mice (E), accompanied by dysregulated activation of sterol regulatory element-binding protein (SREBP) even during fasting conditions (F), leading to increased de novo lipogenesis. Intraperitoneal administration of exogenous PI effectively normalized SREBP cleavage (G), highlighting PI's critical role in SREBP regulation. Furthermore, simultaneous knockout of SCAP with CDS2 restored the normal liver phenotype, implicating SREBP activation as a central mechanism underlying fatty liver development in CDS2 knockout mice (H, I). Conclusion: Deletion of CDS2 in the liver reduced PI levels, subsequently inducing significant fatty liver due to dysregulated SREBP activation. This study underscores the importance of CDS2 in maintaining PI homeostasis, which in turn regulates SREBP activity and lipid metabolism. Our findings provide valuable insights into the pathogenesis of metabolic disorders and offer potential therapeutic strategies for targeting FLD.

Abstract 4140108: A CRISPR-Activation CROP-seq Screen Identifies HMGN1 as a Dosage-Sensitive Regulator of Heart Defects in Down Syndrome

Introduction/Background: Congenital heart defects (CHD) are the most common form of developmental abnormalities, occurring in ~1% of live births, and can arise due to altered dosage of genes essential for cardiogenesis. Aneuploidy accounts for nearly 15% of CHD and the most frequent form involves trisomy of chromosome 21 (Ch21), resulting in Down Syndrome (DS). CHD is present in ~50% of DS cases, with a 1000-fold enrichment of atrioventricular canal (AVC) defects that disrupt the junction of the atria and ventricles. Hypothesis: We hypothesize that the presence of a third copy of one or more genes on Ch21 underlies AVC and other cardiac defects; however, the dosage-sensitive CHD gene(s) on Ch21 causing this are not fully defined. Methods: We used human pluripotent stem cells derived from an individual mosaic for DS, allowing us to compare Ch21 trisomy cells with isogenic control cells disomic for Ch21. We performed single cell RNA-sequencing (scRNA-seq) to define the transcriptional dysregulation associated with DS in atrioventricular canal myocardial cells (AVCM). We then introduced a CRISPR-activation transgene to disomic cells and delivered small guide RNAs (sgRNAs) against 66 candidate Ch21 CHD genes. We developed a new machine learning algorithm to assign a trisomic score to CRISPR perturbed (CROP-seq) cells. Finally, we reduced the copy number of our top candidate gene in a mouse model of Down Syndrome and used microCT to assess incidence of cardiac septal defects. Results: Using human pluripotent stem cell and mouse models of DS, we identify HMGN1, a nucleosome-binding epigenetic factor on Ch21, as a dosage-sensitive regulator of cardiac defects in DS. Single cell transcriptomics revealed that human AVC cardiomyocytes shifted to a more ventricular myocardial state in trisomy 21 hiPS-derived cells. CRISPR-activation in isogenic disomic cells of 66 candidate Ch21 genes expressed in heart development, followed by single cell RNA-sequencing (CROP-seq) combined with machine learning predictions indicated that increased expression levels of HMGN1 altered the transcriptional state of atrioventricular cardiomyocytes similar to trisomy 21. Finally, reduction of Hmgn1 from three to two alleles in a mouse model of DS attenuated the incidence of cardiac septal defects. Conclusion: Our results identify HMGN1 as a dosage sensitive regulator of heart defects in DS and represent a generalizable approach for identifying candidate genes within areas of aneuploidy.

IMMU-39. CAR T CELLS TARGETING ICAM-1 SHOW A SURVIVAL BENEFIT IN BOTH SYNGENEIC AND XENOGRAFT GLIOMA MOUSE MODELS

Abstract BACKGROUND Chimeric antigen receptor (CAR) T-cell therapy, while effective against hematological malignancies, has faced significant hurdles in its application to solid tumors. Challenges in CAR T-cell therapy for glioblastoma include the immunosuppressive tumor microenvironment, the limited infiltration of CAR T-cells into the tumor, heterogeneous target expression and antigen escape. In this study, we focused on targeting Intracellular adhesion molecule-1 (ICAM-1), a protein expressed on both glioma cells and tumor-associated cells like macrophages and endothelial cells. METHODS Glioblastoma and normal brain tissue microarray sections (TMA) were immunohistochemically analyzed for ICAM-1 expression. Second-generation human and murine ICAM-1-targeting CAR T cells were generated by lentiviral or retroviral transduction of T cells from healthy human donors or murine splenocytes. Their efficacy was evaluated in co- culture assays with human and murine glioma and endothelial cell lines. Syngeneic and xenograft orthotopic glioma mouse models were used to assess the in vivo activity of CAR T cells. Ex vivo analysis of these tumors included examination of changes in the tumor microenvironment using high-dimensional flow cytometry. RESULTS Immunohistochemical staining of TMA revealed a significant upregulation of ICAM-1 in human glioblastoma tissue compared to normal brain tissue. Single-cell RNA sequencing data from glioblastoma specimens showed a high level of ICAM-1 expression in tumor- associated macrophages. Human and murine ICAM-1-targeting CAR T cells displayed strong lysis of ICAM-1-expressing glioma and endothelial cells in vitro. Intratumoral application of CAR T cells resulted in a survival benefit in both syngeneic and xenograft glioma mouse models. Ex vivo analysis of the tumor microenvironment revealed treatment-induced changes from our CAR T cell therapy and indicates potential for further enhancements. CONCLUSION Our study demonstrates that ICAM-1-targeting CAR T cells improve survival in human and murine glioma mouse models. Flow cytometry of the tumor microenvironment reveals therapy-induced changes, for future improvements of the CAR T cell therapy.

CNSC-43. NEUROTRANSMITTER DEPENDENCY UNDERLIES TUMOR GROWTH IN HUMANIZED PEDIATRIC LOW-GRADE GLIOMA MODELS

Abstract Brain tumors arise in close association with neurons, suggesting that these non-neoplastic cells may be critical stromal drivers of brain tumor initiation and growth. Previously, we have shown that murine low-grade optic glioma formation and progression in the setting of Neurofibromatosis type 1 (NF1) is dictated by neurons and neuronal activity. In these studies, these neuronal dependencies reflected neuronal activity-driven enzymatic cleavage of a growth factor (neuroligin-3) from oligodendrocyte precursors cells (tumor initiation) or neuronal production of a paracrine factor to stimulate T cell support of optic glioma growth (tumor progression). Since neurons typically communicate with other neurons through neurotransmitters, we sought to explore the possibility that neurotransmitters operate to modulate low-grade glioma growth using humanized mouse models of pilocytic astrocytoma (PA). Leveraging single cell RNA sequencing of three independent sets of pediatric PAs, we identified neurotransmitter pathway enrichment in the tumor cells. This neurotransmitter pathway enrichment reflected aberrant expression of specific neurotransmitter receptors, which we confirmed in three independently generated PA tissue microarrays and in five distinct primary PA cell lines grown in vitro. Moreover, this aberrant neurotransmitter receptor expression established differential neurotransmitter PA growth dependencies in vitro. Importantly, interruption of neurotransmitter signaling in human PA xenografts attenuated tumor growth and ERK activation in Rag1-/- mice in vivo. Finally, we discovered crosstalk between neurotransmitter receptor and receptor tyrosine kinase signaling that revealed another target for therapeutic inhibition. Taken together, these findings elucidate a previously unknown neurotransmitter PA growth dependency amenable to therapeutic targeting.

TMOD-31. SINGLE-CELL PROFILING AND CHARACTERIZATION OF PATIENT-DERIVED XENOGRAFT GLIOBLASTOMA MODEL IN HUMANIZED MICE

Abstract Glioblastoma (GBM) is the most common and aggressive malignant brain tumor in adults, and the current standard therapy has limited efficacy. To develop effective therapies, it is desirable to develop an animal model that can replicate the tumor heterogeneity and immune microenvironment of human GBM. Here, we describe a novel GBM mouse model established with a patient-derived xenograft (PDX) in humanized mice harboring a nearly complete human immune environment. Humanized mice were generated by engrafting human CD34+ hematopoietic stem cells from umbilical cord blood into immunocompromised mice (NSG, NSG-SGM3, and NOG-EXL) after myeloablation. NSG-SGM3 is a triple transgenic mouse encoding human IL3, GM-CSF, and SCF on the NSG strain background. NOG-EXL is a NOG strain with human IL3 and GM-CSF expression. These cytokines foster the development of the human myeloid lineage and its differentiation. NSG-SGM3 and NOG-EXL were superior in immune cell reproducibility, especially myeloid cells. Radioresistant PDX GBM cells established after repeated irradiation were injected into the forebrain of humanized mice and the same immunocompromised mice without humanization. Human PDX GBM cells formed aggressive tumors with similar growth speed in the humanized mice compared to non-humanized mice; however, their dissemination to the spinal cord was significantly suppressed in humanized mice, suggesting that human immune cells impact the spinal dissemination of GBM cells. Single-cell RNA sequencing analysis revealed infiltration of human CD4+ T, CD8+ T, NK cells, and macrophages, as well as infiltration of regulatory T and exhausted CD8+ cells into the brain tumor, reflecting the immunosuppressive landscape of recurrent human GBM. Furthermore, we found that tumor heterogeneity was increased in humanized mice compared to non-humanized mice. There was a notable rise in neural progenitor-like cell populations, indicating tumor adaptation to immune pressures. This novel GBM-PDX humanized mouse model might be highly beneficial for analyzing the interaction between human tumor cells and human immune cells, and evaluating the effect of immunotherapies.

Base-editing corrects metabolic abnormalities in a humanized mouse model for glycogen storage disease type-Ia

Glycogen storage disease type-Ia patients, deficient in the G6PC1 gene encoding glucose-6-phosphatase-α, lack blood glucose control, resulting in life-threatening hypoglycemia. Here we show our humanized mouse model, huR83C, carrying the pathogenic G6PC1-R83C variant displays the phenotype of glycogen storage disease type-Ia and dies prematurely. We evaluate the efficacy of BEAM-301, a formulation of lipid nanoparticles containing a newly-engineered adenine base editor, to correct the G6PC1-R83C variant in huR83C mice and monitor phenotypic correction through one year. BEAM-301 can correct up to ~60% of the G6PC1-R83C variant in liver cells, restores blood glucose control, improves metabolic abnormalities of the disease, and confers long-term survival to the mice. Interestingly, just ~10% base correction is therapeutic. The durable pharmacological efficacy of base editing in huR83C mice supports the development of BEAM-301 as a potential therapeutic for homozygous and compound heterozygous glycogen storage disease type-Ia patients carrying the G6PC1-R83C variant.

Increased exercise tolerance in humanized G6PD deficient mice

Glucose-6-phosphate dehydrogenase (G6PD) deficiency affects 500 million people globally, impacting red blood cell (RBC) antioxidant pathways and increasing susceptibility to hemolysis under oxidative stress. Despite the systemic generation of reactive oxygen species during exercise, the effects of exercise on individuals with G6PD deficiency remain poorly understood This study utilized humanized mouse models expressing the G6PD Mediterranean variant (S188F, with 10% enzymatic activity) to investigate exercise performance and molecular outcomes. Surprisingly, despite decreased enzyme activity, G6PD-deficient mice have faster critical speed (CS) compared to mice expressing human canonical G6PD. Post-exercise, deficient mice did not exhibit differences in RBC morphology or hemolysis, but had improved cardiac function, including cardiac output, stroke volume, sarcomere length and mitochondrial content. Proteomics analyses of cardiac and skeletal muscles (gastrocnemius, soleus) from G6PD deficient compared to sufficient mice revealed improvements in mitochondrial function and increased protein turnover via ubiquitination, especially for mitochondrial and structural myofibrillar proteins. Mass spectrometry-based metabolomics revealed alterations in energy metabolism and fatty acid oxidation. These findings challenge the traditional assumptions regarding hemolytic risk during exercise in G6PD deficiency, suggesting a potential metabolic advantage in exercise performance for individuals carrying non-canonical G6PD variants.

Self‐Assembled Antibody‐Oligonucleotide Conjugates for Targeted Delivery of Complementary Antisense Oligonucleotides

AbstractAntibody‐oligonucleotide conjugate (AOC) affords preferential cell targeting and enhanced cellular uptake of antisense oligonucleotide (ASO). Here, we have developed a modular AOC (MAOC) approach based on accurate self‐assembly of separately prepared antibody and ASO modules. Homogeneous multimeric AOC with defined ASO‐to‐antibody ratio were generated by L–DNA scaffold mediated precise self‐assembly of antibodies and ASOs. The MAOC approach has been implemented to deliver exon skipping ASOs via transferrin receptor (TfR1) mediated internalization. We discovered an anti‐TfR1 sdAb that can greatly enhance nuclear delivery of ASOs. Cryo‐EM structure of the sdAb‐TfR1 complex showed a new epitope that does not overlap with the binding sites of endogenous TfR1 ligands. In vivo functional analyses of MAOCs with one ASO for single exon skipping and two ASOs for double exon skipping showed that both ASO concentration and exon skipping efficacy of MAOC in cardiac and skeletal muscles are dramatically higher than conventional ASOs in the transgenic human TfR1 mouse model. MAOC treatment was well tolerated in vivo and not associated with any toxicity‐related morbidity or mortality. Collectively, our data suggest that the self‐assembled MAOC is a viable option for broadening the therapeutic application of ASO via multi‐specific targeting and delivery.

Preclinical characterization of MTX-101: a novel bispecific CD8 Treg modulator that restores CD8 Treg functions to suppress pathogenic T cells in autoimmune diseases

IntroductionRegulatory CD8 T cells (CD8 Treg) are responsible for the selective killing of self-reactive and pathogenic CD4 T cells. In autoimmune disease, CD8 Treg may accumulate in the peripheral blood but fail to control the expansion of pathogenic CD4 T cells that subsequently cause tissue destruction. This CD8 Treg dysfunction is due in part to the expression of inhibitory killer immunoglobulin-like receptors (KIR; KIR2DL isoforms [KIR2DL1, KIR2DL2, and KIR2DL3]); these molecules serve as autoimmune checkpoints and limit CD8 Treg activation.MethodsHere we describe the pre-clinical characterization of MTX-101, a bispecific antibody targeting inhibitory KIR and CD8. Using human peripheral blood mononuculear cells (PBMC) derived from healthy donors and autoimmune patients, humanized mouse models, and human derived tissue organoids, we evaluated the molecular mechanisms and functional effects of MTX-101.ResultsBy binding to KIR, MTX-101 inhibited KIR signaling that can restore CD8 Treg ability to eliminate pathogenic CD4 T cells. MTX-101 bound and activated CD8 Treg in human peripheral blood mononuclear cells (PBMC), resulting in increased CD8 Treg cytolytic capacity, activation, and prevalence. Enhancing CD8 Treg function with MTX-101 reduced pathogenic CD4 T cell expansion and inflammation, without increasing pro-inflammatory cytokines or activating immune cells that express either target alone. MTX-101 reduced antigen induced epithelial cell death in disease affected tissues, including in tissue biopsies from individuals with autoimmune disease (i.e., celiac disease, Crohn’s disease). The effects of MTX-101 were specific to autoreactive CD4 T cells and did not suppress responses to viral and bacterial antigens. In a human PBMC engrafted Graft versus Host Disease (GvHD) mouse model of acute inflammation, MTX-101 bound CD8 Treg and delayed onset of disease. MTX-101 induced dose dependent binding, increased prevalence and cytolytic capacity of CD8 Treg, as well as increased CD4 T cell death. MTX-101 selectively bound CD8 Treg without unwanted immune cell activation or increase of pro-inflammatory serum cytokines and exhibited an antibody-like half-life in pharmacokinetic and exploratory tolerability studies performed using IL-15 transgenic humanized mice with engrafted human lymphocytes, including CD8 Treg at physiologic ratios.ConclusionCollectively, these data support the development of MTX-101 for the treatment of autoimmune diseases.

A dual-purpose humanized mouse model for testing antiviral strategies against both SIV and HIV

Nonhuman primate (NHP) models employing simian/simian-human immunodeficiency viruses (SIV/SHIVs) played a major role in the study of HIV pathogenesis, latency, and cure studies in a preclinical setting. However, it took many years to arrive at the current effective triple drug ARV regimen against SIV due to the genetic differences with that of HIVs. Since new combinations of drugs will be used in the evolving HIV cure studies, a small animal model would be ideal to determine their efficacy against the commonly used SIVs such as SIVmac239 to triage ineffective drugs prior to their application in NHPs. We recently determined that humanized mice (hu-mice) with a transplanted human immune system are permissive to SIVmac strains in addition to HIVs. Based on this novel finding, here we evaluated the utility of this dual-purpose hu-mouse model to test different ART regimens against SIVmac239. Infected mice showing chronic viremia were treated with a combination anti-retroviral treatment (cART) regimen consisting of emtricitabine/elvitegravir/tenofovir disoproxil fumarate (FTC/EVG/TDF). Full viral suppression was seen for several weeks in SIVmac239-infected and treated mice similar to that seen with HIV-1 BaL virus used as a control. However, viral rebound was eventually observed in SIVmac239 infected mice during the treatment period, suggesting viral escape compared to HIV-1 BaL with which viral suppression was fully sustained. Next, a cART regimen consisting of emtricitabine/bictegravir/tenofovir alafenamide fumarate (FTC/BIC/TAF) was similarly evaluated. Our results showed that this ARV regimen was fully effective in rapidly suppressing both SIVmac239 and HIV-1 BaL. Complete viral suppression was maintained until treatment interruption after which viral loads rebounded. These findings highlight the utility of humanized mice for in vivo screening of new combinations of ARV compounds against various SIVs prior to employing them in NHPs. In addition to identifying new effective cART regimens against SIVs, this model would also be amenable to evaluating immunotherapeutic strategies using broadly neutralizing antibodies, LRAs and novel therapeutics in comparative cure studies of SIV and HIV.

WWOX tuning of oleic acid signaling orchestrates immunosuppressive macrophage polarization and sensitizes hepatocellular carcinoma to immunotherapy

BackgroundImmune checkpoint inhibitors (ICIs) are therapeutically effective for hepatocellular carcinoma (HCC) but are individually selective. This study examined the role of specific common fragile sites (CFSs) related gene in HCC...

Human Dendritic Cell Differentiation in Hematopoietic Stem Cell-Transplanted NOG hFLT3L Tg/mFlt3 KO Humanized Mice

Human immune system-reconstituted humanized mice are useful animal models to study human immunology in vivo. Human hematopoietic stem cell-transferred NOG mice are well recognized as humanized immune system models with reconstitution of mature lymphoid lineage cells such as T and B cells. However, human myeloid lineage cells including dendritic cells (DCs) do not fully differentiate in conventional NOG mice. DCs play a crucial role in adaptive immunity through antigen presentation to T cells to acquire antigen specificity. In this study, we established a novel humanized mouse with human DC differentiation. To induce DCs, we generated human Fms-like tyrosine kinase 3 ligand (hFLT3L) transgenic NOG (hFLT3L-Tg) mice and transferred human CD34+ hematopoietic stem cells (HSC) into them. Unexpectedly, low frequency of human cell engraftment was observed in the hFLT3L-Tg mice after HPC reconstitution. In the Tg mice, mouse CD11b+Gr1− myeloid cells were markedly expanded in the bone marrow due to the cross-reaction between hFLT3L and mouse Flt3 receptor, and these myeloid leukemia-like cells interfered with the engraftment of human hematopoietic cells in hFLT3L-Tg mice. To avoid this cross-reaction, we further generated NOG FLT3 receptor KO (mFlt3 KO) mice by CRISPR/Cas9 technique, and the KO mice combined with hFLT3L Tg mice to create hFLT3L Tg/mFlt3 KO (FL Tg/KO) mice. Mouse CD11b+Gr1− leukemia-like cells did not proliferate in FL Tg/KO mice due to blockade of the FLT3 signals in mouse leukocytes. After human HSC transplantation, human CD45+ cells were successfully engrafted in FL Tg/KO mice. Furthermore, major subsets of human DC populations, cDC1, cDC2, and pDC, and skin Langerhans cells were significantly differentiated in FL Tg/KO mice. Therefore, these humanized mouse models are potentially valuable in the investigation of DC-mediated human adaptive immune responses in vivo.

Current and future medical treatment for endometriosis

Endometriosis is a chronic, progressive inflammatory disease that occurs in approximately 10% of women of reproductive age, resulting in a decreased quality of life due to dysmenorrhea, chronic pain, and other problems. The primary treatment is pain control and fertility preservation, and while preserving ovarian function through drug therapy and surgery, assisted reproductive technology (ART), including in vitro fertilization (IVF), is also utilized. Hormonal therapies such as low-dose estrogen/progestin (LEP), progestins, and GnRH analogs are often the drug of choice. We presented that IAP (inhibitor of apoptotic protein) inhibitors can potentially be novel agents for treating endometriosis. Our studies using cultured cells derived from human endometriotic lesions and mouse models have revealed that inflammatory cytokines and antiapoptotic factors (IAPs) produced by peritoneal macrophages or endometriosis cells are crucial and that NF-κB (nuclear factor-kappa B) plays a central role in the pathogenesis of endometriosis. The high expression of IAPs in human endometriotic tissues, its facilitative role in ectopic survival, and the effect of IAPs on drug-resistant apoptosis of human endometriotic cells indicate its potential as a novel drug for IAP inhibitors. We found that the medicinal herb parthenolide and selective estrogen receptor modulators (SERM) can reduce lesions through NF-κB inhibition. Recently, new findings were obtained by non-invasive observation of early lesions using bioluminescence technology and by applying knockout mouse models. We will show the possibility of new therapeutic agents for endometriosis.

Structure–Activity Relationship Studies of Imidazo[1′,2′:1,6]pyrido[2,3-d]pyrimidine Derivatives to Develop Selective FGFR Inhibitors as Anticancer Agents for FGF19-overexpressed Hepatocellular Carcinoma

The aberrant activation of fibroblast growth factor (FGF) and FGF receptor (FGFR)-mediated signaling pathways are associated with cancer development, including hepatocellular carcinoma (HCC). A novel series of imidazo[1′,2′:1,6]pyrido[2,3-d]pyrimidine, containing an acrylamide covalent warhead, were synthesized as selective FGFR 1-4 inhibitors. Compound 7n was identified as the most potent inhibitor against FGFR1, 2, and 4, with IC50 values of 8/4 nM (FGFR1/2) and 3.8 nM (FGFR4), and the covalent docking analyses suggested that 7n form a covalent adduct with cysteine residue on the hinge or p-loop of FGFR. Compound 7n exhibited a favorable pharmacokinetic profile and significant in vivo antitumor efficacy in human liver cancer xenograft mouse models (xenograft, FGF/FGFR-dependent HCC cells).

Polyclonality overcomes fitness barriers in Apc-driven tumorigenesis.

Loss-of-function mutations in the tumour suppressor APC are an initial step in intestinal tumorigenesis1,2. APC-mutant intestinal stem cells outcompete their wild-type neighbours through the secretion of Wnt antagonists, which accelerates the fixation and subsequent rapid clonal expansion of mutants3-5. Reports of polyclonal intestinal tumours in human patients and mouse models appear at odds with this process6,7. Here we combine multicolour lineage tracing with chemical mutagenesis in mice to show that a large proportion of intestinal tumours have a multiancestral origin. Polyclonal tumours retain a structure comprising subclones with distinct Apc mutations and transcriptional states, driven predominantly by differences in KRAS and MYC signalling. These pathway-level changes are accompanied by profound differences in cancer stem cell phenotypes. Of note, these findings are confirmed by introducing an oncogenic Kras mutation that results in predominantly monoclonal tumour formation. Further, polyclonal tumours have accelerated growth dynamics, suggesting a link between polyclonality and tumour progression. Together, these findings demonstrate the role of interclonal interactions in promoting tumorigenesis through non-cell autonomous pathways that are dependent on the differential activation of oncogenic pathways between clones.

Synergistic Effects of Fructose and Food Preservatives on Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): From Gut Microbiome Alterations to Hepatic Gene Expression.

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing global health problem closely linked to dietary habits, particularly high fructose consumption. This study investigates the combined effects of fructose and common food preservatives (sodium benzoate, sodium nitrite, and potassium sorbate) on the development and progression of MASLD. Methods: We utilized a human microbiota-associated mouse model, administering 10% fructose with or without preservatives for 11 weeks. Liver histology, hepatic gene expression (microarray analysis), biochemical markers, cytokine profiles, intestinal permeability, and gut microbiome composition (16S rRNA and Internal Transcribed Spacer (ITS) sequencing) were evaluated. Results: Fructose and potassium sorbate synergistically induced liver pathology characterized by increased steatosis, inflammation and fibrosis. These histological changes were associated with elevated liver function markers and altered lipid profiles. The treatments also induced significant changes in both the bacterial and fungal communities and disrupted intestinal barrier function, leading to increased pro-inflammatory responses in the mesenteric lymph nodes. Liver gene expression analysis revealed a wide range of transcriptional changes induced by fructose and modulated by the preservative. Key genes involved in lipid metabolism, oxidative stress, and inflammatory responses were affected. Conclusions: Our findings highlight the complex interactions between dietary components, gut microbiota, and host metabolism in the development of MASLD. The study identifies potential risks associated with the combined consumption of fructose and preservatives, particularly potassium sorbate. Our data reveal new mechanisms that are involved in the development of MASLD and open up a new avenue for the prevention and treatment of MASLD through dietary interventions and the modulation of the microbiome.

Novel 1,8-Naphthalimide Derivatives Inhibit Growth and Induce Apoptosis in Human Glioblastoma.

Given the rapid advancement of functional 1,8-Naphthalimide derivatives in anticancer research, we synthesized these two novel naphthalimide derivatives with diverse substituents and investigated the effect on glioblastoma multiforme (GBM) cells. Cytotoxicity, apoptosis, cell cycle, topoisomerase II and Western blotting assays were evaluated for these compounds against GBM in vitro. A human GBM xenograft mouse model established by subcutaneously injecting U87-MG cells and the treatment responses were assessed. Both compounds 3 and 4 exhibited significant antiproliferative activities, inducing apoptosis and cell death. Only compound 3 notably induced G2/M phase cell cycle arrest in the U87-MG GBM cells. Both compounds inhibited DNA topoisomerase II activity, resulting in DNA damage. The in vivo antiproliferative potential of compound 3 was further validated in a U87-MG GBM xenograft mouse model, without any discernible loss of body weight or kidney toxicity noted. This study presents novel findings demonstrating that 1,8-Naphthalimide derivatives exhibited significant GBM cell suppression in vitro and in vivo without causing adverse effects on body weight or kidney function. Further experiments, including investigations into mechanisms and pathways, as well as preclinical studies on the pharmacokinetics and pharmacodynamics, may be instrumental to the development of a new anti-GBM compound.

IRF3 Promotes Asthma Pathogenesis by Regulating Type 2 Innate Lymphoid Cells

ABSTRACT Background Allergic asthma is characterized by airway hyperresponsiveness triggered by inhaled allergens. Type 2 innate lymphoid cells (ILC2s) have been demonstrated to play a crucial role in promoting airway inflammation through the secretion of type 2 effector cytokines. However, the mechanisms underlying the functions of lung ILC2s remain unclear. Methods In this study, we investigated the expression of IRF3 in ILC2s in both human patients and mouse models of asthma. We utilized IRF3-deficient mice to assess the impact of IRF3 deficiency on ILC2 function in a model of IL33-induced asthma. Additionally, we explored the mechanisms underlying IRF3-mediated regulation of ILC2s, focusing on the involvement of the transcription factor Gata3. Results Our findings revealed elevated expression of IRF3 in ILC2s of patients and mice with asthma, suggesting a potential role for IRF3 in the pathogenesis of allergic asthma. Furthermore, we demonstrated that IRF3 deficiency impairedthe expansion and function of ILC2s in IL33-induced asthma, highlighting the importance of IRF3 in regulating ILC2-mediated responses. Importantly, we showed that the regulation of ILC2s by IRF3 was independent of Th2 cells and mediated by the transcription factor Gata3. Conclusion This study identifies IRF3 as a novel regulator of lung ILC2s and suggests its potential as a promising immunotherapeutic target for allergic asthma. These findings shed light on the intricate mechanisms underlying asthma pathogenesis and provide insights into potential strategies for the development of targeted therapies for this prevalent airway disease.