ABSTRACT
Liver-directed adeno-associated viral (AAV) vector-mediated homology-independent targeted integration (AAV-HITI) by CRISPR-Cas9 at the highly transcribed albumin locus is under investigation to provide sustained transgene expression following neonatal treatment. We show that targeting the 3' end of the albumin locus results in productive integration in about 15% of mouse hepatocytes achieving therapeutic levels of systemic proteins in two mouse models of inherited diseases. We demonstrate that full-length HITI donor DNA is preferentially integrated upon nuclease cleavage and that, despite partial AAV genome integrations in the target locus, no gross chromosomal rearrangements or insertions/deletions at off-target sites are found. In line with this, no evidence of hepatocellular carcinoma is observed within the 1-year follow-up. Finally, AAV-HITI is effective at vector doses considered safe if directly translated to humans providing therapeutic efficacy in the adult liver in addition to newborn. Overall, our data support the development of this liver-directed AAV-based knockin strategy.
Subject(s)
Dependovirus , Disease Models, Animal , Genetic Vectors , Liver , Animals , Dependovirus/genetics , Liver/metabolism , Liver/pathology , Mice , Genetic Vectors/genetics , Hepatocytes/metabolism , Humans , Virus Integration/genetics , CRISPR-Cas Systems/genetics , Transgenes , Genetic Diseases, Inborn/genetics , Genetic Diseases, Inborn/therapy , Genetic Therapy/methods , Mice, Inbred C57BL , Albumins/genetics , Albumins/metabolismABSTRACT
Leukemia relapse is a major cause of death after allogeneic hematopoietic cell transplantation (allo-HCT). We tested the potential of targeting T cell (Tc) immunoglobulin and mucin-containing molecule 3 (TIM-3) for improving graft-versus-leukemia (GVL) effects. We observed differential expression of TIM-3 ligands when hematopoietic stem cells overexpressed certain oncogenic-driver mutations. Anti-TIM-3 Ab treatment improved survival of mice bearing leukemia with oncogene-induced TIM-3 ligand expression. Conversely, leukemia cells with low ligand expression were anti-TIM-3 treatment resistant. In vitro, TIM-3 blockade or genetic deletion in CD8+ Tc enhanced Tc activation, proliferation, and IFN-γ production while enhancing GVL effects, preventing Tc exhaustion, and improving Tc cytotoxicity and glycolysis in vivo. Conversely, TIM-3 deletion in myeloid cells did not affect allogeneic Tc proliferation and activation in vitro, suggesting that anti-TIM-3 treatment-mediated GVL effects are Tc induced. In contrast to anti-programmed cell death protein 1 (anti-PD-1) and anti-cytotoxic T lymphocyte-associated protein 4 (anti-CTLA-4) treatment, anti-TIM-3-treatment did not enhance acute graft-versus-host disease (aGVHD). TIM-3 and its ligands were frequently expressed in acute myeloid leukemia (AML) cells of patients with post-allo-HCT relapse. We decipher the connections between oncogenic mutations found in AML and TIM-3 ligand expression and identify anti-TIM-3 treatment as a strategy for enhancing GVL effects via metabolic and transcriptional Tc reprogramming without exacerbation of aGVHD. Our findings support clinical testing of anti-TIM-3 Ab in patients with AML relapse after allo-HCT.
Subject(s)
Hepatitis A Virus Cellular Receptor 2 , Animals , Hepatitis A Virus Cellular Receptor 2/genetics , Hepatitis A Virus Cellular Receptor 2/metabolism , Mice , Hematopoietic Stem Cell Transplantation , Graft vs Leukemia Effect/immunology , Graft vs Leukemia Effect/genetics , Humans , Allografts , Ligands , Oncogenes , CD8-Positive T-Lymphocytes/immunology , Mice, Knockout , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/immunology , Leukemia, Myeloid, Acute/metabolism , Leukemia, Myeloid, Acute/therapy , Leukemia, Myeloid, Acute/pathology , CTLA-4 Antigen/genetics , CTLA-4 Antigen/immunology , CTLA-4 Antigen/metabolism , CTLA-4 Antigen/antagonists & inhibitors , Gene Expression Regulation, LeukemicABSTRACT
Cancer treatment with anti-PD-1 immunotherapy can cause central nervous system immune-related adverse events (CNS-irAEs). The role of microglia in anti-PD-1 immunotherapy-induced CNS-irAEs is unclear. We found that anti-PD-1 treatment of mice caused morphological signs of activation and major histocompatibility complex (MHC) class II up-regulation on microglia. Functionally, anti-PD-1 treatment induced neurocognitive deficits in mice, independent of T cells, B cells, and natural killer cells. Instead, we found that microglia mediated these CNS-irAEs. Single-cell RNA sequencing revealed major transcriptional changes in microglia upon anti-PD-1 treatment. The anti-PD-1 effects were mediated by anti-PD-1 antibodies interacting directly with microglia and were not secondary to peripheral T cell activation. Using a proteomics approach, we identified spleen tyrosine kinase (Syk) as a potential target in activated microglia upon anti-PD-1 treatment. Syk inhibition reduced microglia activation and improved neurocognitive function without impairing anti-melanoma effects. Moreover, we analyzed CNS tissue from a patient cohort that had received anti-PD-1 treatment. Imaging mass cytometry revealed that anti-PD-1 treatment of patients was associated with increased surface marker expression indicative of microglia activation. In summary, we identified a disease-promoting role for microglia in CNS-irAEs driven by Syk and provide an inhibitor-based approach to interfere with this complication after anti-PD-1 immunotherapy.
Subject(s)
Central Nervous System , Immunotherapy , Microglia , Programmed Cell Death 1 Receptor , Animals , Microglia/drug effects , Microglia/metabolism , Microglia/pathology , Immunotherapy/adverse effects , Programmed Cell Death 1 Receptor/metabolism , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Humans , Central Nervous System/pathology , Central Nervous System/drug effects , Mice, Inbred C57BL , Syk Kinase/metabolism , MiceABSTRACT
Increasing evidence supports the interplay between oncogenic mutations and immune escape mechanisms. Strategies to counteract the immune escape mediated by oncogenic signaling could provide improved therapeutic options for patients with various malignancies. As mutant calreticulin (CALR) is a common driver of myeloproliferative neoplasms (MPN), we analyzed the impact of oncogenic CALRdel52 on the bone marrow (BM) microenvironment in MPN. Single-cell RNA-sequencing revealed that CALRdel52 led to the expansion of TGF-ß1-producing erythroid progenitor cells and promoted the expansion of FoxP3+ regulatory T cells (Treg) in a murine MPN model. Treatment with an anti-TGF-ß antibody improved mouse survival and increased the glycolytic activity in CD4+ and CD8+ T cells in vivo, while T cell depletion abrogated the protective effects conferred by neutralizing TGF-ß. TGF-ß1 reduced perforin and TNF-α production by T cells in vitro. TGF-ß1 production by CALRdel52 cells was dependent on JAK1/2, PI3K, and ERK activity, which activated the transcription factor Sp1 to induce TGF-ß1 expression. In four independent patient cohorts, TGF-ß1 expression was increased in the BM of MPN patients compared to healthy individuals, and the BM of MPN patients contained a higher frequency of Treg compared to healthy individuals. Together, this study identified an ERK/Sp1/TGF-ß1 axis in CALRdel52 MPNs as a mechanism of immunosuppression that can be targeted to elicit T-cell-mediated cytotoxicity.
ABSTRACT
Mitochondria react to infection with sub-lethal signals in the apoptosis pathway. Mitochondrial signals can be inflammatory but mechanisms are only partially understood. We show that activation of the caspase-activated DNase (CAD) mediates mitochondrial pro-inflammatory functions and substantially contributes to host defense against viral infection. In cells lacking CAD, the pro-inflammatory activity of sub-lethal signals was reduced. Experimental activation of CAD caused transient DNA-damage and a pronounced DNA damage response, involving major kinase signaling pathways, NF-κB and cGAS/STING, driving the production of interferon, cytokines/chemokines and attracting neutrophils. The transcriptional response to CAD-activation was reminiscent of the reaction to microbial infection. CAD-deficient cells had a diminished response to viral infection. Influenza virus infected CAD-deficient mice displayed reduced inflammation in lung tissue, higher viral titers and increased weight loss. Thus, CAD links the mitochondrial apoptosis system and cell death caspases to host defense. CAD-driven DNA damage is a physiological element of the inflammatory response to infection.
Subject(s)
DNA Damage , Inflammation , Mitochondria , Animals , Humans , Mice , Apoptosis , Deoxyribonucleases/metabolism , Deoxyribonucleases/genetics , Endodeoxyribonucleases/metabolism , Endodeoxyribonucleases/genetics , Endodeoxyribonucleases/deficiency , Inflammation/pathology , Inflammation/metabolism , Mice, Inbred C57BL , Mice, Knockout , Mitochondria/metabolism , NF-kappa B/metabolism , Nucleotidyltransferases , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/virology , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/metabolism , Signal TransductionABSTRACT
Jamaican fruit bats (Artibeus jamaicensis) naturally harbor a wide range of viruses of human relevance. These infections are typically mild in bats, suggesting unique features of their immune system. To better understand the immune response to viral infections in bats, we infected male Jamaican fruit bats with the bat-derived influenza A virus (IAV) H18N11. Using comparative single-cell RNA sequencing, we generated single-cell atlases of the Jamaican fruit bat intestine and mesentery. Gene expression profiling showed that H18N11 infection resulted in a moderate induction of interferon-stimulated genes and transcriptional activation of immune cells. H18N11 infection was predominant in various leukocytes, including macrophages, B cells, and NK/T cells. Confirming these findings, human leukocytes, particularly macrophages, were also susceptible to H18N11, highlighting the zoonotic potential of this bat-derived IAV. Our study provides insight into a natural virus-host relationship and thus serves as a fundamental resource for future in-depth characterization of bat immunology.
Subject(s)
Chiroptera , Orthomyxoviridae Infections , Single-Cell Analysis , Animals , Chiroptera/virology , Chiroptera/immunology , Chiroptera/genetics , Male , Humans , Orthomyxoviridae Infections/virology , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/veterinary , Macrophages/immunology , Macrophages/virology , Influenza A virus/genetics , Influenza A virus/immunology , Gene Expression ProfilingABSTRACT
The collaborative project Personalized Medicine for Oncology (PM4Onco) was launched in 2023 as part of the National Decade against Cancer (NKD) and is executed within the Medical Informatics Initiative (MII). Its aim is to establish a sustainable infrastructure for the integration and use of data from clinical and biomedical research and therefore combines the experience and preliminary work of all four consortia of the MII and the leading oncology centers in Germany. The data provided by PM4Onco will be prepared in a suitable form to support decision making in molecular tumor boards. This concept and infrastructure will be extended to 23 participating partner sites and thus improve access to targeted therapies based on clinical information and analysis of molecular genetic alterations in tumors at different stages of the disease. This will help to improve the treatment and prognosis of tumor diseases.Clinical cancer registries are involved in the project to improve data quality through standardized documentation routines. Clinical experts advise on the expansion of the core datasets for personalized medicine (PM). Information on quality of life and treatment outcomes reported by patients in questionnaires, which is rarely collected outside of clinical trials, will make a significant contribution. Patient representatives are involved from the onset to ensure that the important perspective of patients is taken into account in the decision-making process. PM4Onco thus creates an alliance between the MII, oncological centers of excellence, clinical cancer registries, young scientists, patients, and citizens to strengthen and advance PM in cancer therapy.
Subject(s)
Medical Oncology , Neoplasms , Precision Medicine , Humans , Germany , Intersectoral Collaboration , Medical Informatics/organization & administration , Medical Oncology/organization & administration , Models, Organizational , Neoplasms/therapyABSTRACT
Undesired on- and off-target effects of CRISPR-Cas nucleases remain a challenge in genome editing. While the use of Cas9 nickases has been shown to minimize off-target mutagenesis, their use in therapeutic genome editing has been hampered by a lack of efficacy. To overcome this limitation, we and others have developed double-nickase-based strategies to generate staggered DNA double-strand breaks to mediate gene disruption or gene correction with high efficiency. However, the impact of paired single-strand nicks on genome integrity has remained largely unexplored. Here, we developed a novel CAST-seq pipeline, dual CAST, to characterize chromosomal aberrations induced by paired CRISPR-Cas9 nickases at three different loci in primary keratinocytes derived from patients with epidermolysis bullosa. While targeting COL7A1, COL17A1, or LAMA3 with Cas9 nucleases caused previously undescribed chromosomal rearrangements, no chromosomal translocations were detected following paired-nickase editing. While the double-nicking strategy induced large deletions/inversions within a 10 kb region surrounding the target sites at all three loci, similar to the nucleases, the chromosomal on-target aberrations were qualitatively different and included a high proportion of insertions. Taken together, our data indicate that double-nickase approaches combine efficient editing with greatly reduced off-target effects but still leave substantial chromosomal aberrations at on-target sites.
Subject(s)
CRISPR-Cas Systems , Deoxyribonuclease I , Gene Editing , Keratinocytes , Humans , Gene Editing/methods , Deoxyribonuclease I/metabolism , Deoxyribonuclease I/genetics , Keratinocytes/metabolism , DNA Breaks, Double-Stranded , Chromosome Aberrations , Collagen Type VII/genetics , Collagen Type VII/metabolism , Cells, CulturedABSTRACT
The limited regenerative capacity of the human heart contributes to high morbidity and mortality worldwide. In contrast, zebrafish exhibit robust regenerative capacity, providing a powerful model for studying how to overcome intrinsic epigenetic barriers maintaining cardiac homeostasis and initiate regeneration. Here, we present a comprehensive analysis of the histone modifications H3K4me1, H3K4me3, H3K27me3 and H3K27ac during various stages of zebrafish heart regeneration. We found a vast gain of repressive chromatin marks one day after myocardial injury, followed by the acquisition of active chromatin characteristics on day four and a transition to a repressive state on day 14, and identified distinct transcription factor ensembles associated with these events. The rapid transcriptional response involves the engagement of super-enhancers at genes implicated in extracellular matrix reorganization and TOR signaling, while H3K4me3 breadth highly correlates with transcriptional activity and dynamic changes at genes involved in proteolysis, cell cycle activity, and cell differentiation. Using loss- and gain-of-function approaches, we identified transcription factors in cardiomyocytes and endothelial cells influencing cardiomyocyte dedifferentiation or proliferation. Finally, we detected significant evolutionary conservation between regulatory regions that drive zebrafish and neonatal mouse heart regeneration, suggesting that reactivating transcriptional and epigenetic networks converging on these regulatory elements might unlock the regenerative potential of adult human hearts.
Subject(s)
Chromatin , Gene Regulatory Networks , Heart , Animals , Humans , Mice , Cell Differentiation , Chromatin/metabolism , Chromatin/genetics , Epigenesis, Genetic , Histone Code , Histones/metabolism , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/cytology , Regeneration/genetics , Transcription Factors/metabolism , Transcription Factors/genetics , Zebrafish/geneticsABSTRACT
Acute graft-versus-host disease (aGVHD) is a life-threatening complication of allogeneic hematopoietic cell transplantation (allo-HCT), for which therapeutic options are limited. Strategies to promote intestinal tissue tolerance during aGVHD may improve patient outcomes. Using single-cell RNA sequencing, we identified a lipocalin-2 (LCN2)-expressing neutrophil population in mice with intestinal aGVHD. Transfer of LCN2-overexpressing neutrophils or treatment with recombinant LCN2 reduced aGVHD severity, whereas the lack of epithelial or hematopoietic LCN2 enhanced aGVHD severity and caused microbiome alterations. Mechanistically, LCN2 induced insulin-like growth factor 1 receptor (IGF-1R) signaling in macrophages through the LCN2 receptor SLC22A17, which increased interleukin-10 (IL-10) production and reduced major histocompatibility complex class II (MHCII) expression. Transfer of LCN2-pretreated macrophages reduced aGVHD severity but did not reduce graft-versus-leukemia effects. Furthermore, LCN2 expression correlated with IL-10 expression in intestinal biopsies in multiple cohorts of patients with aGVHD, and LCN2 induced IGF-1R signaling in human macrophages. Collectively, we identified a LCN2-expressing intestinal neutrophil population that reduced aGVHD severity by decreasing MHCII expression and increasing IL-10 production in macrophages. This work provides the foundation for administration of LCN2 as a therapeutic approach for aGVHD.
Subject(s)
Graft vs Host Disease , Hematopoietic Stem Cell Transplantation , Humans , Animals , Mice , Neutrophils/pathology , Interleukin-10 , Lipocalin-2/genetics , Graft vs Host Disease/genetics , Macrophages/pathology , Acute DiseaseABSTRACT
In the original publication [...].
ABSTRACT
The therapeutic use of adeno-associated viral vector (AAV)-mediated gene disruption using CRISPR-Cas9 is limited by potential off-target modifications and the risk of uncontrolled integration of vector genomes into CRISPR-mediated double-strand breaks. To address these concerns, we explored the use of AAV-delivered paired Staphylococcus aureus nickases (D10ASaCas9) to target the Hao1 gene for the treatment of primary hyperoxaluria type 1 (PH1). Our study demonstrated effective Hao1 gene disruption, a significant decrease in glycolate oxidase expression, and a therapeutic effect in PH1 mice. The assessment of undesired genetic modifications through CIRCLE-seq and CAST-Seq analyses revealed neither off-target activity nor chromosomal translocations. Importantly, the use of paired-D10ASaCas9 resulted in a significant reduction in AAV integration at the target site compared to SaCas9 nuclease. In addition, our study highlights the limitations of current analytical tools in characterizing modifications introduced by paired D10ASaCas9, necessitating the development of a custom pipeline for more accurate characterization. These results describe a positive advance towards a safe and effective potential long-term treatment for PH1 patients.
Subject(s)
CRISPR-Cas Systems , Hyperoxaluria, Primary , Humans , Animals , Mice , Deoxyribonuclease I/genetics , Deoxyribonuclease I/metabolism , Gene Editing , Hyperoxaluria, Primary/genetics , Hyperoxaluria, Primary/therapyABSTRACT
Patients with corticosteroid-refractory acute graft-versus-host disease (aGVHD) have a low one-year survival rate. Identification and validation of novel targetable kinases in patients who experience corticosteroid-refractory-aGVHD may help improve outcomes. Kinase-specific proteomics of leukocytes from patients with corticosteroid-refractory-GVHD identified rho kinase type 1 (ROCK1) as the most significantly upregulated kinase. ROCK1/2 inhibition improved survival and histological GVHD severity in mice and was synergistic with JAK1/2 inhibition, without compromising graft-versus-leukemia-effects. ROCK1/2-inhibition in macrophages or dendritic cells prior to transfer reduced GVHD severity. Mechanistically, ROCK1/2 inhibition or ROCK1 knockdown interfered with CD80, CD86, MHC-II expression and IL-6, IL-1ß, iNOS and TNF production in myeloid cells. This was accompanied by impaired T cell activation by dendritic cells and inhibition of cytoskeletal rearrangements, thereby reducing macrophage and DC migration. NF-κB signaling was reduced in myeloid cells following ROCK1/2 inhibition. In conclusion, ROCK1/2 inhibition interferes with immune activation at multiple levels and reduces acute GVHD while maintaining GVL-effects, including in corticosteroid-refractory settings.
Subject(s)
Graft vs Host Disease , rho-Associated Kinases , Humans , Animals , Mice , rho-Associated Kinases/genetics , Graft vs Host Disease/drug therapy , Signal Transduction , NF-kappa B , Adrenal Cortex Hormones/pharmacology , Adrenal Cortex Hormones/therapeutic useABSTRACT
Defective FAS (CD95/Apo-1/TNFRSF6) signaling causes autoimmune lymphoproliferative syndrome (ALPS). Hypergammaglobulinemia is a common feature in ALPS with FAS mutations (ALPS-FAS), but paradoxically, fewer conventional memory cells differentiate from FAS-expressing germinal center (GC) B cells. Resistance to FAS-induced apoptosis does not explain this phenotype. We tested the hypothesis that defective non-apoptotic FAS signaling may contribute to impaired B cell differentiation in ALPS. We analyzed secondary lymphoid organs of patients with ALPS-FAS and found low numbers of memory B cells, fewer GC B cells, and an expanded extrafollicular (EF) B cell response. Enhanced mTOR activity has been shown to favor EF versus GC fate decision, and we found enhanced PI3K/mTOR and BCR signaling in ALPS-FAS splenic B cells. Modeling initial T-dependent B cell activation with CD40L in vitro, we showed that FAS competent cells with transient FAS ligation showed specifically decreased mTOR axis activation without apoptosis. Mechanistically, transient FAS engagement with involvement of caspase-8 induced nuclear exclusion of PTEN, leading to mTOR inhibition. In addition, FASL-dependent PTEN nuclear exclusion and mTOR modulation were defective in patients with ALPS-FAS. In the early phase of activation, FAS stimulation promoted expression of genes related to GC initiation at the expense of processes related to the EF response. Hence, our data suggest that non-apoptotic FAS signaling acts as molecular switch between EF versus GC fate decisions via regulation of the mTOR axis and transcription. The defect of this modulatory circuit may explain the observed hypergammaglobulinemia and low memory B cell numbers in ALPS.
Subject(s)
Hypergammaglobulinemia , Lymphoproliferative Disorders , Humans , Apoptosis/genetics , Germinal Center , Lymphoproliferative Disorders/genetics , TOR Serine-Threonine KinasesABSTRACT
Plasma membrane accumulation of phosphorylated mixed lineage kinase domain-like (MLKL) is a hallmark of necroptosis, leading to membrane rupture and inflammatory cell death. Pro-death functions of MLKL are tightly controlled by several checkpoints, including phosphorylation. Endo- and exocytosis limit MLKL membrane accumulation and counteract necroptosis, but the exact mechanisms remain poorly understood. Here, we identify linear ubiquitin chain assembly complex (LUBAC)-mediated M1 poly-ubiquitination (poly-Ub) as novel checkpoint for necroptosis regulation downstream of activated MLKL in cells of human origin. Loss of LUBAC activity inhibits tumor necrosis factor α (TNFα)-mediated necroptosis, not by affecting necroptotic signaling, but by preventing membrane accumulation of activated MLKL. Finally, we confirm LUBAC-dependent activation of necroptosis in primary human pancreatic organoids. Our findings identify LUBAC as novel regulator of necroptosis which promotes MLKL membrane accumulation in human cells and pioneer primary human organoids to model necroptosis in near-physiological settings.
Subject(s)
Necroptosis , Protein Kinases , Humans , Necrosis/metabolism , Protein Kinases/genetics , Protein Kinases/metabolism , Phosphorylation , Cell Death , Receptor-Interacting Protein Serine-Threonine Kinases/genetics , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , Apoptosis/physiologyABSTRACT
Juvenile myelomonocytic leukaemia (JMML) is characterized by gene variants that deregulate the RAS signalling pathway. Children with neurofibromatosis type 1 (NF-1) carry a defective NF1 allele in the germline and are predisposed to JMML, which presumably requires somatic inactivation of the NF1 wild-type allele. Here we examined the two-hit concept in leukaemic cells of 25 patients with JMML and NF-1. Ten patients with JMML/NF-1 exhibited a NF1 loss-of-function variant in combination with uniparental disomy of the 17q arm. Five had NF1 microdeletions combined with a pathogenic NF1 variant and nine carried two compound-heterozygous NF1 variants. We also examined 16 patients without clinical signs of NF-1 and no variation in the JMML-associated driver genes PTPN11, KRAS, NRAS or CBL (JMML-5neg) and identified eight patients with NF1 variants. Three patients had microdeletions combined with hemizygous NF1 variants, three had compound-heterozygous NF1 variants and two had heterozygous NF1 variants. In addition, we found a high incidence of secondary ASXL1 and/or SETBP1 variants in both groups. We conclude that the clinical diagnosis of JMML/NF-1 reliably indicates a NF1-driven JMML subtype, and that careful NF1 analysis should be included in the genetic workup of JMML even in the absence of clinical evidence of NF-1.
Subject(s)
Leukemia, Myelomonocytic, Juvenile , Neurofibromatosis 1 , Child , Humans , Leukemia, Myelomonocytic, Juvenile/genetics , Neurofibromatosis 1/genetics , Mutation , Signal Transduction , Genes, Tumor SuppressorABSTRACT
Juvenile myelomonocytic leukemia (JMML) is an aggressive hematopoietic disorder of infancy and early childhood driven by constitutively active RAS signaling and characterized by abnormal proliferation of the granulocytic-monocytic blood cell lineage. Most JMML patients require hematopoietic stem cell transplantation for cure, but the risk of relapse is high for some JMML subtypes. Azacitidine was shown to effectively reduce leukemic burden in a subset of JMML patients. However, variable response rates to azacitidine and the risk of drug resistance highlight the need for novel therapeutic approaches. Since RAS signaling is known to interfere with the intrinsic apoptosis pathway, we combined various BH3 mimetic drugs with azacitidine in our previously established patient-derived xenograft model. We demonstrate that JMML cells require both MCL-1 and BCL-XL for survival, and that these proteins can be effectively targeted by azacitidine and BH3 mimetic combination treatment. In vivo azacitidine acts via downregulation of antiapoptotic MCL-1 and upregulation of proapoptotic BH3-only. The combination of azacitidine with BCL-XL inhibition was superior to BCL-2 inhibition in eliminating JMML cells. Our findings emphasize the need to develop clinically applicable MCL-1 or BCL-XL inhibitors in order to enable novel combination therapies in JMML refractory to standard therapy.
Subject(s)
Azacitidine , Leukemia, Myelomonocytic, Juvenile , Humans , Child, Preschool , Azacitidine/pharmacology , Azacitidine/therapeutic use , Leukemia, Myelomonocytic, Juvenile/drug therapy , Myeloid Cell Leukemia Sequence 1 Protein/metabolism , bcl-X Protein/metabolism , Apoptosis , Cell Line, TumorABSTRACT
BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory disorder characterized by a life-threatening cytokine storm and immunopathology. Familial HLH type 3 (FHL3) accounts for approximately 30% of all inborn HLH cases worldwide. It is caused by mutations in the UNC13D gene that result in impaired degranulation of cytotoxic vesicles and hence compromised T-cell- and natural killer-cell-mediated killing. Current treatment protocols, including allogeneic hematopoietic stem cell (HSC) transplantation, still show high mortality. OBJECTIVE: We sought to develop and evaluate a curative genome editing strategy in the preclinical FHL3 Jinx mouse model. Jinx mice harbor a cryptic splice donor site in Unc13d intron 26 and develop clinical symptoms of human FHL3 upon infection with lymphocytic choriomeningitis virus (LCMV). METHODS: We employed clustered regularly interspaced short palindromic repeats (CRISPR)-Cas technology to delete the disease-causing mutation in HSCs and transplanted Unc13d-edited stem cells into busulfan-conditioned Jinx recipient mice. Safety studies included extensive genotyping and chromosomal aberrations analysis by single targeted linker-mediated PCR sequencing (CAST-Seq)-based off-target analyses. Cure from HLH predisposition was assessed by LCMV infection. RESULTS: Hematopoietic cells isolated from transplanted mice revealed efficient gene editing (>95%), polyclonality of the T-cell receptor repertoire, and neither signs of off-target effects nor leukemogenesis. Unc13d transcription levels of edited and wild-type cells were comparable. While LCMV challenge resulted in acute HLH in Jinx mice transplanted with mock-edited HSCs, Jinx mice grafted with Unc13d-edited cells showed rapid virus clearance and protection from HLH. CONCLUSIONS: Our study demonstrates that transplantation of CRISPR-Cas edited HSCs supports the development of a functional polyclonal T-cell response in the absence of genotoxicity-associated clonal outgrowth.
Subject(s)
Lymphohistiocytosis, Hemophagocytic , Humans , Mice , Animals , Lymphohistiocytosis, Hemophagocytic/genetics , Lymphohistiocytosis, Hemophagocytic/therapy , Lymphohistiocytosis, Hemophagocytic/diagnosis , T-Lymphocytes , Gene Editing , Mutation , Lymphocytic choriomeningitis virus , Hematopoietic Stem Cells , Membrane Proteins/geneticsABSTRACT
BACKGROUND: In molecular tumor boards (MTBs), patients with rare or advanced cancers are discussed by a multidisciplinary team of health care professionals. Software support for MTBs is lacking; in particular, tools for preparing and documenting MTB therapy recommendations need to be developed. OBJECTIVE: We aimed to implement an extension to cBioPortal to provide a tool for the documentation of therapy recommendations from MTB sessions in a secure and standardized manner. The developed extension should be embedded in the patient view of cBioPortal to enable easy documentation during MTB sessions. The resulting architecture for storing therapy recommendations should be integrable into various hospital information systems. METHODS: On the basis of a requirements analysis and technology analysis for authentication techniques, a prototype was developed and iteratively refined through a user-centered development process. In conclusion, the tool was evaluated via a usability evaluation, including interviews, structured questionnaires, and the System Usability Scale. RESULTS: The patient view of cBioPortal was extended with a new tab that enables users to document MTB sessions and therapy recommendations. The role-based access control was expanded to allow for a finer distinction among the rights to view, edit, and delete data. The usability evaluation showed overall good usability and a System Usability Scale score of 83.57. CONCLUSIONS: This study demonstrates how cBioPortal can be extended to not only visualize MTB patient data but also be used as a documentation platform for therapy recommendations.