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1.
J Hepatol ; 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38972484

ABSTRACT

BACKGROUND AND AIM: The induction of effective CD8+ T cells is thought to play a critical role in the functional cure of chronic hepatitis B (CHB). Additionally, the use of checkpoint inhibitors is being evaluated to overcome T cell dysfunction during CHB. APPROACH AND RESULTS: A chimpanzee adenoviral vector (ChAdOx1-HBV) and a Modified vaccinia Ankara boost (MVA-HBV) encoding the inactivated polymerase, core, and S region from a consensus genotype C HBV were studied. The trial enrolled 55 patients with virally-suppressed CHB virus infection and HBsAg <4,000 IU/mL Group 1 received MVA-HBV intramuscularly (IM) on Day 0 and 28, Group 2 received ChAdOx1-HBV on Day 0/MVA-HBV on Day 28 (VTP-300), Group 3 received VTP-300 + low-dose nivolumab (LDN) on Day 28, and Group 4 received VTP-300 plus LDN with both injections. VTP-300 alone and in combination with LDN was well tolerated with no treatment-related serious adverse events. Reductions of HBsAg were demonstrated in the VTP-300 group 2: 3 of 18 patients with starting HBsAg < 50 IU/ml had durable log10 declines > 0.7 log10 2 months post last-dose. Group 3 (N=18) had reductions in HBsAg of 0.76 log10 and 0.80 log10 3 (p<0.001) at 2 and 7 months post last dose. Two developed persistent non-detectable HBsAg levels. CD4+ and CD8+ antigen-specific T cell responses were generated and there was a correlation between IFN-y ELISpot response and HBsAg decline in Group 2. CONCLUSIONS: VTP-300 induced CD4+ and CD8+ T cells and lowered HBsAg in a subset of patients with baseline values below 100 IU/ml. The addition of LDN resulted in significant reduction in surface antigen. VTP-300 is a promising immunotherapeutic to move forward alone or in combination therapies. IMPACT AND IMPLICATIONS: The induction of potent, durable CD8+ T cells may be critical to achieving a functional cure in chronic hepatitis B virus infection. A prime-boost immunotherapeutic consisting of an adenoviral-vector encoding hepatitis B antigens followed by a pox virus boost was shown to induce CD8+ T cells and to lower HBsAg in CHB patients, either alone or more impactfully when administered in conjunction with a checkpoint inhibitor. The use of immunotherapeutics CLINTRIALS: NCT047789.

3.
Phys Chem Chem Phys ; 26(20): 14970-14979, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38739372

ABSTRACT

Curcumin is a medicinal agent that exhibits anti-cancer and anti-Alzheimer's disease properties. It has a keto-enol moiety that gives rise to many of its chemical properties including metal complexation and acid-base equilibria. A previous study has shown that keto-enol tautomerization at this moiety is implicated in the anti-Alzheimer's disease effect of curcumin, highlighting the importance of this process. In this study, tautomerization of curcumin in methanol, acetone and acetonitrile was investigated using time-resolved 1H nuclear magnetic resonance spectroscopy. Curcumin undergoes hydrogen-deuterium exchange with the solvents and the proton resonance peak corresponding to the hydrogen at the α-carbon position (Cα) decays as a function of time, signifying deuteration at this position. Because tautomerization is the rate limiting step in the deuteration of curcumin at the Cα position, the rate of tautomerization is inferred from the rate of deuteration. The rate constant of tautomerization of curcumin shows a temperature dependence and analysis using the Arrhenius equation revealed activation energies (Ea) of tautomerization of (80.1 ± 5.9), (64.1 ± 1.0) and (68.3 ± 5.5) kJ mol-1 in methanol, D2O/acetone and D2O/acetonitrile, respectively. Insight into the role of water in tautomerization of curcumin was further offered by density functional theory studies. The transition state of tautomerization was optimized in the presence of water molecules. The results show a hydrogen-bonded solvent bridge between the diketo moiety and Cα of curcumin. The Ea of tautomerization of curcumin shows a strong dependence on the number of water molecules in the solvent bridge, indicating the critical role played by the solvent bridge in catalyzing tautomerization of curcumin.


Subject(s)
Curcumin , Curcumin/chemistry , Methanol/chemistry , Acetonitriles/chemistry , Acetone/chemistry , Isomerism , Thermodynamics , Solvents/chemistry
4.
Cancer Cell ; 42(5): 904-914.e9, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38579724

ABSTRACT

A subset of patients with IDH-mutant glioma respond to inhibitors of mutant IDH (IDHi), yet the molecular underpinnings of such responses are not understood. Here, we profiled by single-cell or single-nucleus RNA-sequencing three IDH-mutant oligodendrogliomas from patients who derived clinical benefit from IDHi. Importantly, the tissues were sampled on-drug, four weeks from treatment initiation. We further integrate our findings with analysis of single-cell and bulk transcriptomes from independent cohorts and experimental models. We find that IDHi treatment induces a robust differentiation toward the astrocytic lineage, accompanied by a depletion of stem-like cells and a reduction of cell proliferation. Furthermore, mutations in NOTCH1 are associated with decreased astrocytic differentiation and may limit the response to IDHi. Our study highlights the differentiating potential of IDHi on the cellular hierarchies that drive oligodendrogliomas and suggests a genetic modifier that may improve patient stratification.


Subject(s)
Brain Neoplasms , Cell Differentiation , Isocitrate Dehydrogenase , Mutation , Oligodendroglioma , Oligodendroglioma/genetics , Oligodendroglioma/pathology , Oligodendroglioma/drug therapy , Isocitrate Dehydrogenase/genetics , Isocitrate Dehydrogenase/antagonists & inhibitors , Humans , Cell Differentiation/drug effects , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Brain Neoplasms/drug therapy , Cell Lineage/drug effects , Receptor, Notch1/genetics , Receptor, Notch1/metabolism , Cell Proliferation/drug effects , Animals , Astrocytes/metabolism , Astrocytes/drug effects , Astrocytes/pathology , Mice , Single-Cell Analysis/methods
5.
Cell Rep Med ; 5(3): 101465, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38460518

ABSTRACT

The manipulation of T cell metabolism to enhance anti-tumor activity is an area of active investigation. Here, we report that activating the amino acid starvation response in effector CD8+ T cells ex vivo using the general control non-depressible 2 (GCN2) agonist halofuginone (halo) enhances oxidative metabolism and effector function. Mechanistically, we identified autophagy coupled with the CD98-mTOR axis as key downstream mediators of the phenotype induced by halo treatment. The adoptive transfer of halo-treated CD8+ T cells into tumor-bearing mice led to robust tumor control and curative responses. Halo-treated T cells synergized in vivo with a 4-1BB agonistic antibody to control tumor growth in a mouse model resistant to immunotherapy. Importantly, treatment of human CD8+ T cells with halo resulted in similar metabolic and functional reprogramming. These findings demonstrate that activating the amino acid starvation response with the GCN2 agonist halo can enhance T cell metabolism and anti-tumor activity.


Subject(s)
CD8-Positive T-Lymphocytes , Neoplasms , Humans , Animals , Mice , Immunotherapy, Adoptive/methods , Neoplasms/pathology , Immunotherapy , Amino Acids
6.
Cell Death Differ ; 31(3): 265-279, 2024 03.
Article in English | MEDLINE | ID: mdl-38383888

ABSTRACT

PirB is an inhibitory cell surface receptor particularly prominent on myeloid cells. PirB curtails the phenotypes of activated macrophages during inflammation or tumorigenesis, but its functions in macrophage homeostasis are obscure. To elucidate PirB-related functions in macrophages at steady-state, we generated and compared single-cell RNA-sequencing (scRNAseq) datasets obtained from myeloid cell subsets of wild type (WT) and PirB-deficient knockout (PirB KO) mice. To facilitate this analysis, we developed a novel approach to clustering parameter optimization called "Cluster Similarity Scoring and Distinction Index" (CaSSiDI). We demonstrate that CaSSiDI is an adaptable computational framework that facilitates tandem analysis of two scRNAseq datasets by optimizing clustering parameters. We further show that CaSSiDI offers more advantages than a standard Seurat analysis because it allows direct comparison of two or more independently clustered datasets, thereby alleviating the need for batch-correction while identifying the most similar and different clusters. Using CaSSiDI, we found that PirB is a novel regulator of Cebpb expression that controls the generation of Ly6Clo patrolling monocytes and the expansion properties of peritoneal macrophages. PirB's effect on Cebpb is tissue-specific since it was not observed in splenic red pulp macrophages (RPMs). However, CaSSiDI revealed a segregation of the WT RPM population into a CD68loIrf8+ "neuronal-primed" subset and an CD68hiFtl1+ "iron-loaded" subset. Our results establish the utility of CaSSiDI for single-cell assay analyses and the determination of optimal clustering parameters. Our application of CaSSiDI in this study has revealed previously unknown roles for PirB in myeloid cell populations. In particular, we have discovered homeostatic functions for PirB that are related to Cebpb expression in distinct macrophage subsets.


Subject(s)
CCAAT-Enhancer-Binding Protein-beta , Macrophages , Receptors, Immunologic , Single-Cell Analysis , Animals , Mice , Macrophages/metabolism , Monocytes/metabolism , Myeloid Cells/metabolism , Receptors, Cell Surface , Receptors, Immunologic/metabolism , Single-Cell Analysis/methods , CCAAT-Enhancer-Binding Protein-beta/metabolism
7.
Adv Mater ; 36(15): e2309672, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38206096

ABSTRACT

Development of both organic photovoltaics (OPVs) and organic photocatalysts has focused on utilizing the bulk heterojunction (BHJ). The BHJ promotes charge separation and enhances the carrier lifetime, but may give rise to increased charge traps, hindering performance. Here, high photocatalytic and photovoltaic performance is displayed by electron donor-acceptor (D-A) nanoparticles (NPs) and films, using the nonfullerene acceptor Y6 and polymer donor PIDT-T8BT. In contrast to conventional D-A systems, the charge generation in PIDT-T8BT:Y6 NPs is mainly driven by Y6, allowing a high performance even at a low D:A mass ratio of 1:50. The high performance at the low mass ratio is attributed to the amorphous behavior of PIDT-T8BT. Low ratios are generally thought to yield lower efficiency than the more conventional ≈1:1 ratio. However, the OPVs exhibit peak performance at a D:A ratio of 1:5. Similarly the NPs used for photocatalytic hydrogen evolution show peak performance at the 1:6.7 D:A ratio. Interestingly, for the PIDT-T8BT:Y6 system, as the polymer proportion increases, a reduced photocatalytic and photovoltaic performance is observed. The unconventional D:A ratios provide lower recombination losses and increased charge-carrier lifetime with undisrupted ambipolar charge transport in bulk Y6, enabling better performance than conventional ratios. This work reports novel light-harvesting materials in which performance is reduced due to unfavorable morphology as D:A ratios move toward conventional ratios of 1:1.2-1:1.

8.
J Am Chem Soc ; 146(3): 2174-2186, 2024 Jan 24.
Article in English | MEDLINE | ID: mdl-38197858

ABSTRACT

Polyacenes, such as tetracene and pentacene, are common model systems for the study of photophysical phenomena such as singlet fission (SF) and triplet fusion, processes which may lead to increased photovoltaic efficiencies. While they exhibit desirable photophysical properties, these materials are not photostable and convert to unwanted endoperoxides in the presence of oxygen and light, limiting their use in real-world applications. Not only does oxygen degrade polyacenes but also it can affect their photophysics, leading to both the sensitization and quenching of different excited states. In this study, we characterize the effect of oxygen on 5,12-bis(triisopropylsilylethynyl) tetracene (TIPS-Tn) and 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn) using transient absorption spectroscopy, and show that oxygen can significantly influence the population of excited states, in particular enhancing the polyacene triplet population. We additionally combine the time-resolved excited-state dynamics with photodegradation studies to determine the predominant mechanism of photooxidation, which has previously been unclear. We find that both molecules photodegrade predominantly via singlet oxygen; however, for TIPS-Tn, this occurs through the triplet state, whereas for TIPS-Pn, degradation occurs through the excited singlet. The photodegradation of TIPS-Tn is thus enhanced by faster rates of SF, whereas SF in TIPS-Pn increases the molecule's photostability. This work has implications both for the design of new materials for next-generation photovoltaics that can avoid photooxidation and for the study of their photophysics in real-world environments.

9.
Leukemia ; 38(3): 502-512, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38114624

ABSTRACT

CFI-400945 is a selective oral polo-like kinase 4 (PLK4) inhibitor that regulates centriole duplication. PLK4 is aberrantly expressed in patients with acute myeloid leukemia (AML). Preclinical studies indicate that CFI-400945 has potent in vivo efficacy in hematological malignancies and xenograft models, with activity in cells harboring TP53 mutations. In this phase 1 study in very high-risk patients with relapsed/refractory AML and myelodysplastic syndrome (MDS) (NCT03187288), 13 patients were treated with CFI-400945 continuously in dose escalation from 64 mg/day to 128 mg/day. Three of the 9 efficacy evaluable AML patients achieved complete remission (CR). Two of 4 AML patients (50%) with TP53 mutations and complex monosomal karyotype achieved a CR with 1 patient proceeding to allogenic stem cell transplant. A third patient with TP53 mutated AML had a significant reduction in marrow blasts by > 50% with an improvement in neutrophil and platelet counts. Responses were observed after 1 cycle of therapy. Dose-limiting toxicity was enteritis/colitis. A monotherapy and combination therapy study with a newer crystal form of CFI-400945 in patients with AML, MDS and chronic myelomonocytic leukemia (CMML) is ongoing (NCT04730258).


Subject(s)
Indazoles , Indoles , Leukemia, Myeloid, Acute , Leukemia, Myelomonocytic, Chronic , Myelodysplastic Syndromes , Humans , Leukemia, Myeloid, Acute/genetics , Myelodysplastic Syndromes/genetics , Leukemia, Myelomonocytic, Chronic/drug therapy , Disease-Free Survival , Protein Serine-Threonine Kinases/genetics
10.
J Cardiovasc Dev Dis ; 10(11)2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37998521

ABSTRACT

BACKGROUND: The adaptation of retrograde tibial-pedal access for peripheral angiogram and intervention is limited by the lack of operator experience and concern for small distal vessel injury. This study evaluates the safety of the retrograde tibial-pedal access for peripheral angiogram and intervention in patients with two vessel infra-popliteal artery chronic total occlusions, where the access point is the sole remaining non-occluded infra-popliteal artery. METHODS: A retrospective analysis of 5687 consecutive patients who underwent peripheral angiograms by retrograde tibial-pedal access via the single remaining non-occluded infra-popliteal artery was performed. Patients who had retrograde tibial-pedal access at the sole remaining infra-popliteal artery confirmed by angiography were included. Clinical and ultrasound data of the accessed infra-popliteal vessel up to 6 months were collected. RESULTS: The cohort consisted of 314 patients (152 males; mean age 77.9 years). At 6 months, access vessel complications occurred in 15 patients (4.8%). Access vessel occlusion occurred in 9 out of 314 patients (2.9%), arteriovenous fistula in 4 (1.3%), with spontaneous resolution in 2, pseudoaneurysm requiring thrombin injection in 2 (0.6%) and non-cardiovascular death in 1 (0.3%). No uncontrolled bleeding, procedure-related hospitalizations or limb amputations occurred. CONCLUSIONS: Routine primary retrograde tibial-pedal access for lower extremity peripheral artery diagnostic angiography and intervention in patients with single infra-popliteal artery runoff can be safety performed in an outpatient setting with infrequent and manageable complications.

11.
J Clin Invest ; 133(20)2023 10 16.
Article in English | MEDLINE | ID: mdl-37843275

ABSTRACT

Carcinogen exposure has been associated with enhanced cancer immunogenicity that is often attributed to neoantigen generation. However, the broader, neoantigen-independent impact of carcinogens on immune responses to cancer cells remains underexplored. In this issue of the JCI, Huang et al. uncover a mechanism wherein carcinogen-treated cancer cells exhibit an inability to establish an immunosuppressive tumor microenvironment (TME) due to reduced M-CSF expression. Intriguingly, the so-called carcinogen-induced tumor-associated macrophages (TAMs) within this TME exhibited anti-tumor properties instead of the conventional immunosuppressive phenotype. This phenomenon extended to human lung cancers, as evidenced by TAM reprogramming in smokers versus nonsmokers. This study substantially advances our understanding of carcinogen-mediated effects on cancer immunogenicity, potentially redirecting approaches to cancer immunotherapy.


Subject(s)
Lung Neoplasms , Neoplasms , Humans , Carcinogens/toxicity , Immunotherapy , Immunosuppressive Agents , Lung Neoplasms/therapy , Phenotype , Tumor Microenvironment , Neoplasms/therapy
12.
Proc Natl Acad Sci U S A ; 120(39): e2307999120, 2023 09 26.
Article in English | MEDLINE | ID: mdl-37729199

ABSTRACT

Asbestos is the main cause of malignant mesothelioma. Previous studies have linked asbestos-induced mesothelioma to the release of HMGB1 from the nucleus to the cytoplasm, and from the cytoplasm to the extracellular space. In the cytoplasm, HMGB1 induces autophagy impairing asbestos-induced cell death. Extracellularly, HMGB1 stimulates the secretion of TNFα. Jointly, these two cytokines kick-start a chronic inflammatory process that over time promotes mesothelioma development. Whether the main source of extracellular HMGB1 were the mesothelial cells, the inflammatory cells, or both was unsolved. This information is critical to identify the targets and design preventive/therapeutic strategies to interfere with asbestos-induced mesothelioma. To address this issue, we developed the conditional mesothelial HMGB1-knockout (Hmgb1ΔpMeso) and the conditional myelomonocytic-lineage HMGB1-knockout (Hmgb1ΔMylc) mouse models. We establish here that HMGB1 is mainly produced and released by the mesothelial cells during the early phases of inflammation following asbestos exposure. The release of HMGB1 from mesothelial cells leads to atypical mesothelial hyperplasia, and in some animals, this evolves over the years into mesothelioma. We found that Hmgb1ΔpMeso, whose mesothelial cells cannot produce HMGB1, show a greatly reduced inflammatory response to asbestos, and their mesothelial cells express and secrete significantly reduced levels of TNFα. Moreover, the tissue microenvironment in areas of asbestos deposits displays an increased fraction of M1-polarized macrophages compared to M2 macrophages. Supporting the biological significance of these findings, Hmgb1ΔpMeso mice showed a delayed and reduced incidence of mesothelioma and an increased mesothelioma-specific survival. Altogether, our study provides a biological explanation for HMGB1 as a driver of asbestos-induced mesothelioma.


Subject(s)
Asbestos , HMGB1 Protein , Mesothelioma, Malignant , Mesothelioma , Animals , Mice , Tumor Necrosis Factor-alpha/genetics , HMGB1 Protein/genetics , Mesothelioma/chemically induced , Mesothelioma/genetics , Asbestos/toxicity , Inflammation , Tumor Microenvironment
13.
Nat Cancer ; 4(10): 1437-1454, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37640929

ABSTRACT

Cholinergic nerves are involved in tumor progression and dissemination. In contrast to other visceral tissues, cholinergic innervation in the hepatic parenchyma is poorly detected. It remains unclear whether there is any form of cholinergic regulation of liver cancer. Here, we show that cholinergic T cells curtail the development of liver cancer by supporting antitumor immune responses. In a mouse multihit model of hepatocellular carcinoma (HCC), we observed activation of the adaptive immune response and induction of two populations of CD4+ T cells expressing choline acetyltransferase (ChAT), including regulatory T cells and dysfunctional PD-1+ T cells. Tumor antigens drove the clonal expansion of these cholinergic T cells in HCC. Genetic ablation of Chat in T cells led to an increased prevalence of preneoplastic cells and exacerbated liver cancer due to compromised antitumor immunity. Mechanistically, the cholinergic activity intrinsic in T cells constrained Ca2+-NFAT signaling induced by T cell antigen receptor engagement. Without this cholinergic modulation, hyperactivated CD25+ T regulatory cells and dysregulated PD-1+ T cells impaired HCC immunosurveillance. Our results unveil a previously unappreciated role for cholinergic T cells in liver cancer immunobiology.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Animals , Mice , Carcinoma, Hepatocellular/genetics , Liver Neoplasms/genetics , Programmed Cell Death 1 Receptor/genetics , Monitoring, Immunologic , T-Lymphocytes, Regulatory/pathology
14.
Circulation ; 148(1): 74-94, 2023 07 04.
Article in English | MEDLINE | ID: mdl-37154053

ABSTRACT

Asian American individuals make up the fastest growing racial and ethnic group in the United States. Despite the substantial variability that exists in type 2 diabetes and atherosclerotic cardiovascular disease risk among the different subgroups of Asian Americans, the current literature, when available, often fails to examine these subgroups individually. The purpose of this scientific statement is to summarize the latest disaggregated data, when possible, on Asian American demographics, prevalence, biological mechanisms, genetics, health behaviors, acculturation and lifestyle interventions, pharmacological therapy, complementary alternative interventions, and their impact on type 2 diabetes and atherosclerotic cardiovascular disease. On the basis of available evidence to date, we noted that the prevalences of type 2 diabetes and stroke mortality are higher in all Asian American subgroups compared with non-Hispanic White adults. Data also showed that atherosclerotic cardiovascular disease risk is highest among South Asian and Filipino adults but lowest among Chinese, Japanese, and Korean adults. This scientific statement discusses the biological pathway of type 2 diabetes and the possible role of genetics in type 2 diabetes and atherosclerotic cardiovascular disease among Asian American adults. Challenges to provide evidence-based recommendations included the limited data on Asian American adults in risk prediction models, national surveillance surveys, and clinical trials, leading to significant research disparities in this population. The large disparity within this population is a call for action to the public health and clinical health care community, for whom opportunities for the inclusion of the Asian American subgroups should be a priority. Future studies of atherosclerotic cardiovascular disease risk in Asian American adults need to be adequately powered, to incorporate multiple Asian ancestries, and to include multigenerational cohorts. With advances in epidemiology and data analysis and the availability of larger, representative cohorts, furthering refining the Pooled Cohort Equations, in addition to enhancers, would allow better risk estimation in segments of the population. Last, this scientific statement provides individual- and community-level intervention suggestions for health care professionals who interact with the Asian American population.


Subject(s)
Asian , Atherosclerosis , Diabetes Mellitus, Type 2 , Adult , Humans , American Heart Association , Asian/ethnology , Asian/statistics & numerical data , Atherosclerosis/epidemiology , Atherosclerosis/ethnology , Atherosclerosis/etiology , Atherosclerosis/therapy , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/ethnology , Cardiovascular Diseases/etiology , Cardiovascular Diseases/therapy , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/ethnology , Diabetes Mellitus, Type 2/etiology , Diabetes Mellitus, Type 2/therapy , United States/epidemiology
15.
Cancer Cell ; 41(2): 323-339.e10, 2023 02 13.
Article in English | MEDLINE | ID: mdl-36736318

ABSTRACT

Angioimmunoblastic T cell lymphoma (AITL) is a peripheral T cell lymphoma that originates from T follicular helper (Tfh) cells and exhibits a prominent tumor microenvironment (TME). IDH2 and TET2 mutations co-occur frequently in AITL, but their contribution to tumorigenesis is poorly understood. We developed an AITL mouse model that is driven by Idh2 and Tet2 mutations. Malignant Tfh cells display aberrant transcriptomic and epigenetic programs that impair TCR signaling. Neoplastic Tfh cells bearing combined Idh2 and Tet2 mutations show altered cross-talk with germinal center B cells that promotes B cell clonal expansion while decreasing Fas-FasL interaction and reducing B cell apoptosis. The plasma cell count and angiogenesis are also increased in the Idh2-mutated tumors, implying a major relationship between Idh2 mutation and the characteristic AITL TME. Our mouse model recapitulates several features of human IDH2-mutated AITL and provides a rationale for exploring therapeutic targeting of Tfh-TME cross-talk for AITL patients.


Subject(s)
Dioxygenases , Immunoblastic Lymphadenopathy , Lymphoma, T-Cell , Animals , Humans , Mice , Dioxygenases/genetics , DNA-Binding Proteins/genetics , Immunoblastic Lymphadenopathy/genetics , Isocitrate Dehydrogenase/genetics , Lymphoma, T-Cell/genetics , Mutation , T Follicular Helper Cells/pathology , T-Lymphocytes, Helper-Inducer , Tumor Microenvironment/genetics
16.
Phys Chem Chem Phys ; 25(9): 6817-6829, 2023 Mar 01.
Article in English | MEDLINE | ID: mdl-36790866

ABSTRACT

Singlet fission (SF) holds the promise to circumvent the photovoltaic efficiency limit to reach a power-conversion efficiency above 34%. SF of TIPS-pentacene (TIPS-Pn) has been investigated but its mechanism is yet to be well elucidated. Recently, we developed a nanoparticle (NP) system, in which doping of TIPS-Pn in a host matrix yields a range of average intermolecular distances, d, to study the dependence of SF in TIPS-Pn on d. At large d values, where the bimolecular SF process should be unfavourable, a relatively high SF quantum yield (ΦSF) is still observed, which implies a deviation from a random distribution of TIPS-Pn throughout the NP. Here, using polarisation-sensitive femtosecond time-resolved spectroscopy and Monte Carlo simulations of exciton migration and SF, we quantify the level of clustering of TIPS-Pn in the host matrix, which is responsible for the higher than expected ΦSF. The experimental data indicate a preservation of polarisation correlation by SF, which is uncommon because energy transfer in amorphous materials tends to result in depolarisation. We show that the preservation of polarisation correlation is due to SF upon exciton migration. Although exciton migration decorrelates polarisation, SF acts to remove decorrelated excitons to give an overall preservation of polarisation correlation.

17.
Phys Chem Chem Phys ; 25(6): 4743-4753, 2023 Feb 08.
Article in English | MEDLINE | ID: mdl-36691831

ABSTRACT

Photosynthesis has been shown to be a highly efficient process for energy transfer in plants and bacteria. Like natural photosynthetic systems, the artificial light harvesting complex (LHC) BODIPY pillar[5]arene exhibits Förster resonance energy transfer (FRET). However, extensive characterisation of the BODIPY pillar[5]arene LHC to determine its suitability as an artificial LHC has yet to occur. In this paper we experimentally and computationally investigate the photophysical properties of the LHC by comparing the light absorption of the BODIPY LHC to individual BODIPY chromophores. Our results show evidence for quantum coherence, with oscillation frequencies of 100 cm-1 and 600 cm-1, which are attributable to vibronic, or exciton-phonon type coupling. Computational analysis suggests strong couplings of the molecular orbitals of the LHC resulting from the stacking of neighbouring BODIPY chromophore units. Interestingly, we find a 40% reduction in the absorbance of light for the BODIPY LHC compared to the individual chromophores which we attribute to electronic interactions between the conjugated π-systems of the BODIPY chromophores and the pillar[5]arene backbone.

18.
Proc Natl Acad Sci U S A ; 120(4): e2208176120, 2023 01 24.
Article in English | MEDLINE | ID: mdl-36652477

ABSTRACT

Mutations in IDH1, IDH2, and TET2 are recurrently observed in myeloid neoplasms. IDH1 and IDH2 encode isocitrate dehydrogenase isoforms, which normally catalyze the conversion of isocitrate to α-ketoglutarate (α-KG). Oncogenic IDH1/2 mutations confer neomorphic activity, leading to the production of D-2-hydroxyglutarate (D-2-HG), a potent inhibitor of α-KG-dependent enzymes which include the TET methylcytosine dioxygenases. Given their mutual exclusivity in myeloid neoplasms, IDH1, IDH2, and TET2 mutations may converge on a common oncogenic mechanism. Contrary to this expectation, we observed that they have distinct, and even opposite, effects on hematopoietic stem and progenitor cells in genetically engineered mice. Epigenetic and single-cell transcriptomic analyses revealed that Idh2R172K and Tet2 loss-of-function have divergent consequences on the expression and activity of key hematopoietic and leukemogenic regulators. Notably, chromatin accessibility and transcriptional deregulation in Idh2R172K cells were partially disconnected from DNA methylation alterations. These results highlight unanticipated divergent effects of IDH1/2 and TET2 mutations, providing support for the optimization of genotype-specific therapies.


Subject(s)
DNA-Binding Proteins , Dioxygenases , Isocitrate Dehydrogenase , Stem Cells , Animals , Mice , Dioxygenases/genetics , DNA-Binding Proteins/genetics , Isocitrate Dehydrogenase/genetics , Isocitrate Dehydrogenase/metabolism , Ketoglutaric Acids/metabolism , Mutation , Neoplasms , Stem Cells/metabolism
19.
Cell Death Differ ; 30(2): 407-416, 2023 02.
Article in English | MEDLINE | ID: mdl-36528755

ABSTRACT

Experimental autoimmune encephalomyelitis (EAE) is a mouse model of multiple sclerosis (MS) in which Th17 cells have a crucial but unclear function. Here we show that choline acetyltransferase (ChAT), which synthesizes acetylcholine (ACh), is a critical driver of pathogenicity in EAE. Mice with ChAT-deficient Th17 cells resist disease progression and show reduced brain-infiltrating immune cells. ChAT expression in Th17 cells is linked to strong TCR signaling, expression of the transcription factor Bhlhe40, and increased Il2, Il17, Il22, and Il23r mRNA levels. ChAT expression in Th17 cells is independent of IL21r signaling but dampened by TGFß, implicating ChAT in controlling the dichotomous nature of Th17 cells. Our study establishes a cholinergic program in which ACh signaling primes chronic activation of Th17 cells, and thereby constitutes a pathogenic determinant of EAE. Our work may point to novel targets for therapeutic immunomodulation in MS.


Subject(s)
Encephalomyelitis, Autoimmune, Experimental , Multiple Sclerosis , Mice , Animals , Th17 Cells , Virulence , Cholinergic Agents , Multiple Sclerosis/genetics , Acetylcholine/metabolism , Mice, Inbred C57BL , Cell Differentiation
20.
Front Cardiovasc Med ; 9: 1038353, 2022.
Article in English | MEDLINE | ID: mdl-36523356

ABSTRACT

Objective: The aim of this study is to compare the quality-of-life (QOL) outcomes and the tibio-pedal arterial pressure post-endovascular intervention. Background: Physiological assessment of peripheral arterial lesions is infrequently performed during endovascular interventions. Materials and methods: We retrospectively reviewed all 343 patients with intermittent claudication who underwent an endovascular intervention via tibio-pedal artery access from October 2018 to May 2021. The baseline and post-intervention tibio-pedal arterial pressures from the pedal sheaths were measured. QOL was assessed using a pre-validated Walking Impairment Questionnaire (WIQ) score before and at 30-day after intervention. We compared the baseline tibio-pedal arterial pressure, post-intervention tibio-pedal arterial pressure, delta pressure (post-intervention minus baseline), baseline WIQ scores, 30-day WIQ scores, and delta score (30-day minus baseline). Results: All 343 patients had successful tibio-pedal accesses. The average tibio-pedal arterial pressure at baseline was 87.0 ± 1.8 mmHg vs. 135.5 ± 1.7 mmHg post-intervention (p < 0.001). Average baseline and 30-day WIQ scores were summation (99.8 ± 3.3 vs. 115.0 ± 3.1, p < 0.001), walking distance (35.7 ± 1.3 vs. 42.5 ± 1.3, p < 0.001), walking speed (21.1 ± 0.9 vs. 23.6 ± 0.8, p = 0.036), stair climbing (4.7 ± 1.4 vs. 24.2 ± 1.4, p = 0.019), and symptoms (18.8 ± 0.2 vs. 20.1 ± 0.2, p < 0.001), respectively. When comparing the increased post-intervention tibio-pedal arterial pressure <60 mmHg vs. ≥60 mmHg, the average delta WIQ scores were all significantly improved with summation (10.0 ± 3.9 to 25.8 ± 5.5, p = 0.01), walking distance (4.1 ± 1.7 to 9.8 ± 2.5, p = 0.02), walking speed (1.5 ± 1.1 to 4.3 ± 1.5, p = 0.02), stair climbing (2.3 ± 1.8 to 9.4 ± 2.5, p = 0.02), and symptoms (1.0 ± 0.3 to 1.8 ± 0.4, p = 0.04), respectively. Conclusion: Increasing the post-intervention tibio-pedal arterial pressure by 60 mmHg can enhance QOL as suggested by improvement of WIQ scores.

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