Blood最新文献

Clonal hematopoiesis of indeterminate potential (CHIP) is characterized by age-related somatic mutations in hematopoietic stem and progenitor cells (HSC/Ps) and is correlated with an increased risk of myeloid malignancies, elevated inflammatory pathways in circulating myeloid cells, higher all-cause mortality, chronic kidney disease, and cardiovascular disease. The pathophysiology of inflammatory bowel disease (IBD) is intrinsically linked to heightened inflammation. Nevertheless, the presence of CHIP in IBD and its role in the pathophysiology of IBD remains poorly elucidated. In the UK Biobank, CHIP was associated with an increased incidence of IBD. Females with CHIP had a 1.33-fold higher risk, which was further validated in All of Us data base (ßOR = 1.29). For Crohn's disease, DNMT3A mutations conferred a 1.81-fold increased incidence in females compared to non-DNMT3A-carriers, which rose to 2.09 for large clones (variant allele fraction ≥10%). In contrast, for ulcerative colitis, TET2 large clones were significantly associated, and only among individuals under 45. These associations were further identified using two-sample Mendelian randomization. In a mouse model of CHIP-IBD, HSC/Ps with Dnmt3a mutation demonstrated significantly worse pathophysiology compared to controls, due in part to heightened expression of Apurinic/apyrimidinic endonuclease 1 (APE1) in the bone marrow and colon. Treatment with the APE1/Ref-1 inhibitor APX3330 ameliorated CHIP-IBD driven by the Dnmt3a mutation.

Menin inhibitors (MI) disrupt the binding of Menin to MLL1 leading to repression of MLL1 or MLL1-fusion protein (FP) target genes, including reduced levels of HOXA9 and MEIS1 in AML with mutant (mt) NPM1 or MLL1-rearrangement (r). While MIs are relatively well-tolerated and induce clinical remissions, these are often short-lived due to development of resistance followed by AML relapse. Through repeated shocks with the MI SNDX-50469, a precursor tool compound to revumenib, followed by recovery, we developed MI-resistant (MITR) AML MV4-11 and OCI-AML3 cells. Present studies show that, compared to MI-sensitive parental cells, MITR cells exhibit an altered epigenome, transcriptome and proteome, without Menin mutations. Through a CRISPR screen, novel druggable MI co-enrichments were identified and targeted, including BRD4, SMARCA4, and CREBBP. Co-treatment with the MI and the SMARCA4/SMARCA2 (BRG1/BRM) inhibitor FHD-286 or the BET proteins inhibitor OTX015 (birabresib), synergistically induced in vitro lethality in MITR and MI-resistant AML cells expressing the mutant Menin (M327I), as well as in patient-derived (PD) AML cells with MLL1-r or mtNPM1 that exhibited ex vivo resistance to MI. Compared to each drug alone, co-treatment with SNDX-5613 (revumenib) and FHD-286 or OTX015 and FHD-286 significantly reduced the in vivo AML burden and improved survival of the immune depleted mice, without inducing significant toxicity, in the xenograft models of MITR and MI-resistant PD MLL1-r AML cells. These findings highlight novel, targeted, drug combinations that overcome MI resistance in AML cells with MLL1-r or mtNPM1.

Targeting mitochondrial oxidative phosphorylation (OXPHOS) enhances the effects of standard chemotherapy and overcomes treatment resistance in pre-clinical models of acute myeloid leukaemia (AML). So far, the few clinically available OXPHOS inhibitors have shown adverse effects or limited potency in clinical trials, therefore, identification of safe and effective drugs that can target mitochondrial metabolism in AML is critical. Here, we performed a high-throughput drug-repurposing screen, designed to identify clinically applicable OXPHOS-specific inhibitors through nutrient sensing. We uncover itraconazole, an FDA-approved antifungal compound, as a potent OXPHOS inhibitor in AML cells. Mechanistically, through stable isotope-assisted metabolomics and functional studies, we reveal that CYP51A1, which is part of the cytochrome P450 family and the prime target of azole antifungals, is involved in mitochondrial respiration and ETC complex I activity in AML cells. Critically, we demonstrate that itraconazole and related azole antifungals interfere with tricarboxylic acid cycle activity and inhibit OXPHOS through the inhibition of electron transport chain complex I activity. Over-expression of yeast NADH dehydrogenase-1 (NDI1) restored mitochondrial NADH oxidation and complex I activity upon itraconazole treatment. Using patient-derived cells and pre-clinical xenograft models, we demonstrate that itraconazole targets therapy-resistant leukaemic stem cells (LSCs) when used in combination with cytarabine, highlighting the repurposing potential for itraconazole as a clinically safe and effective therapeutic option for AML LSC eradication.

Chimeric antigen receptor T (CAR-T) cell therapy has demonstrated curative potential in B cell malignancies, yet translating this success to chronic infections like human immunodeficiency virus (HIV) remains a major challenge. In people living with HIV (PLWH) on suppressive antiretroviral therapy (ART), low antigen levels limit CAR-T cell expansion and persistence. We previously reported data from a pilot study which suggested that HIV-targeted CD4CAR-T cells could overcome this barrier through exogenous antigen supplementation, leading to robust in vivo expansion. Here, we sought to comprehensively confirm and expand on those findings. We tested a broad array of strategies to enhance CD4CAR-T cell efficacy, including CRISPR-Cas9-mediated gene editing of immune checkpoint and HIV-associated genes, single and pooled competitive infusions of engineered CAR-T cells, distinct CAR constructs incorporating either CD28 or 4-1BB costimulatory domains, and exogenous antigen boosting. We also developed highly sensitive droplet digital PCR (ddPCR) assays both to quantify CAR-T cell frequency and corroborate flow cytometry-based quantification of CD4CAR T-cell expansion. We evaluated these new approaches across multiple NHP models of HIV, including both simian immunodeficiency virus (SIV)- and simian-human immunodeficiency virus (SHIV)-infected, ART-suppressed NHPs. Although CD4CAR-T cell products exhibited antigen-specific proliferation and cytotoxicity ex vivo, they failed to expand, persist, or control viremia in vivo. We were also unable to confirm previously observed CD4CAR T cell expansions from our earlier studies, which will be retracted. Together these data highlight the need for alternative strategies to potentiate anti-HIV CD4CAR-T cells in the immunocompetent setting.