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1.
Clin Cancer Res ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38727700

RESUMO

PURPOSE: Tissue derived tumor mutation burden (TMB) of ≥10 mutations/Mb is a histology agnostic biomarker for the immune checkpoint inhibitor (ICI) pembrolizumab. However, the dataset on which this was validated lacked colorectal cancers (CRCs), and there is limited evidence for immunotherapy benefit in CRC using this threshold. PATIENTS AND METHODS: CO.26 was a randomized phase II study of 180 patients comparing durvalumab and tremelimumab (D+T, n=119 patients) versus best supportive care (BSC, n=61 patients). ctDNA sequencing was available for 168 patients (n=118 D+T, n=50), of which 165 had evaluable plasma TMB (pTMB). Tissue sequencing was available for 108 patients. Optimal thresholds for stratifying patients based on overall survival were determined using a minimal p-value approach. This report includes the final overall survival analysis. RESULTS: Tissue TMB ≥10 mutations/Mb was not predictive of benefit from D+T compared to BSC in microsatellite stable (MSS) metastatic CRC (HR 0.71 [95% CI:0.28-1.80], p=0.47). No tissue TMB threshold could identify a high TMB group that benefited from ICI. In contrast, plasma TMB (pTMB) ≥28 mutations/Mb was predictive of benefit from D+T (HR=0.34 [95%CI:0.13-0.85], p=0.022), as was clonal pTMB ≥10.6 mutations/Mb (HR=0.10 [95%CI:0.014-0.79], p=0.029) and subclonal pTMB ≥25.9/Mb (HR=0.20 [95% CI:0.061-0.69], p=0.010). Higher pTMB was associated with length of time on cytotoxic agents (p=0.021) and prior anti-EGFR exposure (p=2.44x10-06). CONCLUSION: pTMB derived from either clonal or subclonal mutations may identify a group more likely to benefit from immunotherapy, though validation is required. Tissue TMB provided no predictive utility for immunotherapy in this trial.

2.
Chem Mater ; 36(6): 2810-2818, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38558918

RESUMO

Material design is increasingly used to realize desired functional properties, and the perovskite structure family is one of the richest and most diverse: perovskites are employed in many applications due to their structural flexibility and compositional diversity. Hexagonal, layered perovskite structures with chains of face-sharing transition metal oxide octahedra have attracted great interest as quantum materials due to their magnetic and electronic properties. Ba4MMn3O12, a member of the "12R" class of hexagonal, layered perovskites, contains trimers of face-sharing MnO6 octahedra that are linked by a corner-sharing, bridging MO6 octahedron. Here, we investigate cluster magnetism in the Mn3O12 trimers and the role of this bridging octahedron on the magnetic properties of two isostructural 12R materials by systematically changing the M4+ cation from nonmagnetic Ce4+ (f0) to magnetic Pr4+ (f1). We synthesized 12R-Ba4MMn3O12 (M= Ce, Pr) with high phase purity and characterized their low-temperature crystal structures and magnetic properties. Using substantially higher purity samples than previously reported, we confirm the frustrated antiferromagnetic ground state of 12R-Ba4PrMn3O12 below TN ≈ 7.75 K and explore the cluster magnetism of its Mn3O12 trimers. Despite being atomically isostructural with 12R-Ba4CeMn3O12, the f1 electron associated with Pr4+ causes much more complex magnetic properties in 12R-Ba4PrMn3O12. In 12R-Ba4PrMn3O12, we observe a sharp, likely antiferromagnetic transition at T2 ≈ 12.15 K and an additional transition at T1 ≈ 200 K, likely in canted antiferromagnetic order. These results suggest that careful variation of composition within the family of hexagonal, layered perovskites can be used to tune material properties using the complex role of the Pr4+ ion in magnetism.

3.
Transplantation ; 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38587506

RESUMO

BACKGROUND: Despite ongoing improvements to regimens preventing allograft rejection, most cardiac and other organ grafts eventually succumb to chronic vasculopathy, interstitial fibrosis, or endothelial changes, and eventually graft failure. The events leading to chronic rejection are still poorly understood and the gut microbiota is a known driving force in immune dysfunction. We previously showed that gut microbiota dysbiosis profoundly influences the outcome of vascularized cardiac allografts and subsequently identified biomarker species associated with these differential graft outcomes. METHODS: In this study, we further detailed the multifaceted immunomodulatory properties of protolerogenic and proinflammatory bacterial species over time, using our clinically relevant model of allogenic heart transplantation. RESULTS: In addition to tracing longitudinal changes in the recipient gut microbiome over time, we observed that Bifidobacterium pseudolongum induced an early anti-inflammatory phenotype within 7 d, whereas Desulfovibrio desulfuricans resulted in a proinflammatory phenotype, defined by alterations in leukocyte distribution and lymph node (LN) structure. Indeed, in vitro results showed that B pseudolongum and D desulfuricans acted directly on primary innate immune cells. However, by 40 d after treatment, these 2 bacterial strains were associated with mixed effects in their impact on LN architecture and immune cell composition and loss of colonization within gut microbiota, despite protection of allografts from inflammation with B pseudolongum treatment. CONCLUSIONS: These dynamic effects suggest a critical role for early microbiota-triggered immunologic events such as innate immune cell engagement, T-cell differentiation, and LN architectural changes in the subsequent modulation of protolerant versus proinflammatory immune responses in organ transplant recipients.

4.
ACS Cent Sci ; 10(4): 907-919, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38680557

RESUMO

The response of an oxide crystal to the atmosphere can be personified as breathing-a dynamic equilibrium between O2 gas and O2- anions in the solid. We characterize the analogous defect reaction in an iodide double-perovskite semiconductor, Cs2SnI6. Here, I2 gas is released from the crystal at room temperature, forming iodine vacancies. The iodine vacancy defect is a shallow electron donor and is therefore ionized at room temperature; thus, the loss of I2 is accompanied by spontaneous n-type self-doping. Conversely, at high I2 pressures, I2 gas is resorbed by the perovskite, consuming excess electrons as I2 is converted to 2I-. Halide mobility and irreversible halide loss or exchange reactions have been studied extensively in halide perovskites. However, the reversible exchange equilibrium between iodide and iodine [2I-(s) ↔ I2(g) + 2e-] described here has often been overlooked in prior studies, though it is likely general to halide perovskites and operative near room temperature, even in the dark. An analysis of the 2I-(s)/I2(g) equilibrium thermodynamics and related transport kinetics in single crystals of Cs2SnI6 therefore provides insight toward achieving stable composition and electronic properties in the large family of iodide perovskite semiconductors.

5.
Nano Lett ; 24(7): 2415-2420, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38323579

RESUMO

Electrostatic gating has emerged as a powerful technique for tailoring the magnetic properties of two-dimensional (2D) magnets, offering exciting prospects including enhancement of magnetic anisotropy, boosting Curie temperature, and strengthening exchange coupling effects. Here, we focus on electrical control of the ferromagnetic resonance of the quasi-2D Kagome magnet Cu(1,3-bdc). By harnessing an electrostatic field through ionic liquid gating, significant shifts are observed in the ferromagnetic resonance field in both out-of-plane and in-plane measurements. Moreover, the effective magnetization and gyromagnetic ratios display voltage-dependent variations. A closer examination reveals that the voltage-induced changes can modulate magnetocrystalline anisotropy by several hundred gauss, while the impact on orbital magnetization remains relatively subtle. Density functional theory (DFT) calculations reveal varying d-orbital hybridizations at different voltages. This research unveils intricate physics within the Kagome lattice magnet and further underscores the potential of electrostatic manipulation in steering magnetism with promising implications for the development of spintronic devices.

6.
Clin Radiol ; 79(5): 371-377, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38341344

RESUMO

AIM: To evaluate and compare the rates of local recurrence in hepatocellular carcinoma (HCC) patients who undergo selective transarterial radioembolisation (TARE) or transarterial chemoembolisation (TACE) and achieve a complete response (CR) radiologically. MATERIALS AND METHODS: All patients undergoing treatment with TARE or TACE at a single academic institution were reviewed retrospectively. Those who had been treated previously, presented with multifocal disease, had non-selective TARE or TACE, or did not achieve a complete response (CR) radiologically were excluded. RESULTS: In total 110 patients were included (TACE n=60 [54.5%]; TARE n=50 [45.5%]). TARE patients were older (66.4 ± 9.4 versus 61.2 ± 5.6 years, p<0.001) and had larger tumours (4.4 ± 2.2 versus 3 ± 1.4 cm, p=0.002). TACE patients were significantly more likely to suffer a local recurrence (31/60, 51.7% versus 9/50, 18%, p<0.001) and had a significantly shorter time to recurrence (median 8.3 {interquartile range [IQR]}: 12 versus median 17.9 [IQR: 23.5] months, p=0.001). A local time to progression (TTP) Kaplan-Meier curve demonstrated TACE patients had a significantly shorter local TTP (hazard ratio [HR]: 7.2; 95% confidence interval [CI]: 3.64-14.24; p<0.001) and treatment modality (TACE or TARE; HR: 0.05; 95% CI: 0.005-0.5; p=0.01) was found to be associated with local recurrences on multivariate Cox proportional HR analysis. When overall TTP was evaluated, again TACE patients were found to have a significantly shorter TTP (HR: 2.13 [1.28-3.53], p=0.004). CONCLUSION: In HCC patients undergoing selective treatment who achieve a CR radiologically, those treated with TARE may be less likely to suffer recurrence, either local or general, than those treated with TACE.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/etiologia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/etiologia , Estudos Retrospectivos , Quimioembolização Terapêutica/efeitos adversos , Modelos de Riscos Proporcionais , Resposta Patológica Completa , Resultado do Tratamento
7.
J Immunol ; 212(6): 974-981, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38251917

RESUMO

Activation and clonal expansion of the Ag-specific adaptive immune response in the draining lymph node is essential to clearing influenza A virus infections. Activation sufficient for virus clearance is dependent on the lymph node's architectural organization that is maintained by stromal cells, chiefly fibroblastic reticular cells. During an analysis of influenza A virus clearance in leptin receptor knockout (DB/DB) mice, we observed that the DB/DB mice have markedly reduced numbers of lymph node fibroblastic reticular cells at the steady state. The reduction in lymph node fibroblastic reticular cells resulted in abnormal lymph node organization and diminished numbers of adaptive immune cells in the lymph nodes under homeostatic conditions. As a consequence, the DB/DB mice were impaired in their ability to generate an effective influenza-specific adaptive immune response, which prevented virus clearance. Using leptin receptor mutant mice with point mutations at distinct signaling sites in the leptin receptor, we were able to link the leptin receptor's signaling domain tyrosine 985, which does not contribute to obesity, to lymph node fibroblastic reticular cell development and function. These results demonstrate a novel role for leptin receptor signaling in regulating lymph node development in a manner that is crucial to the generation of Ag-specific adaptive immune responses.


Assuntos
Imunidade Adaptativa , Receptores para Leptina , Camundongos , Animais , Receptores para Leptina/genética , Linfonodos , Transdução de Sinais , Camundongos Endogâmicos C57BL , Leptina
8.
Ann R Coll Surg Engl ; 106(1): 96-98, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36622223

RESUMO

Spontaneous tumour regression is a rare but well-documented phenomenon, especially for renal cell carcinomas. We describe the case of a 60-year-old male who presented with chest pain and shortness of breath. He was diagnosed with a large type A aortic dissection and an incidental right renal mass, highly suspicious of a renal cell carcinoma. Following repair of the dissection, subsequent imaging showed that the renal mass had largely resolved. Spontaneous tumour regression is commonly thought to occur through immunological mechanisms. A vascular cause of tumour regression through infarction is postulated in this case. Although angioembolisation is a well-recognised management option in the context of palliative treatment of symptomatic renal tumours, this case suggests an extended role for angioembolisation in the treatment of small renal masses.


Assuntos
Dissecção Aórtica , Carcinoma de Células Renais , Neoplasias Renais , Masculino , Humanos , Pessoa de Meia-Idade , Rim/irrigação sanguínea , Dissecção Aórtica/diagnóstico por imagem , Carcinoma de Células Renais/diagnóstico por imagem , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/patologia , Artéria Renal
9.
Viruses ; 15(12)2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38140612

RESUMO

Novel swine orthopneumovirus (SOV) infections have been identified in pigs in the USA and some European countries but not in Asian countries, including South Korea, to date. The current study reports the first SOV infections in four domestic pig farms located in four provinces across South Korea. The detection rate of SOV in oral fluid samples using qRT-PCR was 4.4% (14/389), indicating the presence of the virus in pigs at commercial farms in Korea. Two complete genome sequences and one glycoprotein (G) gene sequence were obtained from SOV-positive samples. The complete genome analysis of KSOV-2201 and KSOV-2202 strains showed 98.2 and 95.4% homologies with a previously reported SOV, and the phylogenetic tree exhibited a high correlation with a previously reported SOV strain from the US and a canine pneumovirus (CPnV) strain from China. Based on the genetic analysis of the viral G gene, the murine pneumonia virus (MPV)-like orthopneumoviruses (MLOVs) were divided into two genogroups (G1 and G2). Seventeen CPnVs and two feline pneumoviruses were grouped into G1, while the Korean SOV strains identified in this study were grouped into G2 along with one SOV and two CPnVs. These results will contribute to expanding our understanding of the geographical distribution and genetic characteristics of the novel SOV in the global pig population.


Assuntos
Pneumovirus , Doenças dos Suínos , Camundongos , Suínos , Animais , Gatos , Cães , Sus scrofa , Vírus Sinciciais Respiratórios , Fazendas , Filogenia , Doenças dos Suínos/epidemiologia , República da Coreia/epidemiologia
10.
Angew Chem Int Ed Engl ; 62(50): e202314148, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-37874975

RESUMO

Increasing the chemical diversity of organic semiconductors is essential to develop efficient electronic devices. In particular, the replacement of carbon-carbon (C-C) bonds with isoelectronic boron-nitrogen (B-N) bonds allows precise modulation of the electronic properties of semiconductors without significant structural changes. Although some researchers have reported the preparation of B2 N2 anthracene derivatives with two B-N bonds, no compounds with continuous multiple BN units have been prepared yet. Herein, we report the synthesis and characterization of a B2 N2 anthracene derivative with a BNBN unit formed by converting the BOBN unit at the zigzag edge. Compared to the all-carbon analogue 2-phenylanthracene, BNBN anthracene exhibits significant variations in the C-C bond length and a larger highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap. The experimentally determined bond lengths and electronic properties of BNBN anthracene are confirmed through theoretical calculations. The BOBN anthracene organic light-emitting diode, used as a blue host, exhibits a low driving voltage. The findings of this study may facilitate the development of larger acenes with multiple BN units and potential applications in organic electronics.

11.
Innate Immun ; 29(7): 150-158, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37800911

RESUMO

Immune mediated graft loss still represents a major risk to transplant recipients. Creative approaches to immunosuppression that exploit the recipient's own alloregulatory mechanisms could reduce the need for pharmacologic immunosuppression and potentially induce immune tolerance. In the process of studying recipient derived myeloid derived suppressor cells (MDSCs), we identified key alloregulatory MDSC mechanisms, mediated by isolatable proteins IL-4, IL-34, and IL-10. We sought to purify these proteins and fuse them for subsequent infusion into transplant recipients as a means of inducing an alloregulatory response. In this introductory investigation, we leveraged molecular engineering technology to create a fusion protein (FP) of three cytokine coding sequences of IL-4, IL-34, and IL-10 and demonstrated their expressions by Western Blot analysis. Following purification, we tested whether FP IL-4/IL-34/IL-10 (FP1) can protect heart transplant allografts. Injection of FP1 significantly prolonged allogeneic cardiac graft survival in a dose-dependent fashion and the increase of graft survival time exceeded survival attributable to IL-34 alone. In vitro, MDSCs cells were expanded by FP1 treatment. However, FP1 did not directly inhibit T cell proliferation in vitro. In conclusion, newly developed FP1 improves the graft survival in cardiac transplantation mouse model. Significant additional work to optimize FP1 or include other novel proteins could supplement current treatment options for transplant patients.


Assuntos
Transplante de Coração , Interleucina-10 , Humanos , Animais , Camundongos , Interleucina-10/genética , Interleucina-4 , Doadores de Tecidos , Aloenxertos , Camundongos Endogâmicos C57BL
12.
Nat Chem ; 15(12): 1780-1786, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37640854

RESUMO

Although Cu2+ is ubiquitous, the relativistic destabilization of the 5d orbitals makes the isoelectronic Au2+ exceedingly rare, typically stabilized only through Au-Au bonding or by using redox non-innocent ligands. Here we report the perovskite Cs4AuIIAuIII2Cl12, an extended solid with mononuclear Au2+ sites, which is stable to ambient conditions and characterized by single-crystal X-ray diffraction. The 2+ oxidation state of Au was assigned using 197Au Mössbauer spectroscopy, electron paramagnetic resonance, and magnetic susceptibility measurements, with comparison to paramagnetic and diamagnetic analogues with Cu2+ and Pd2+, respectively, as well as to density functional theory calculations. This gold perovskite offers an opportunity to study the optical and electronic transport of the uncommon Au2+/3+ mixed-valence state and the characteristics of the elusive Au2+ ion coordinated to simple ligands. Compared with the perovskite Cs2AuIAuIIICl6, which has been studied since the 1920s, Cs4AuIIAuIII2Cl12 exhibits a 0.7 eV reduction in optical absorption onset and a 103-fold increase in electronic conductivity.

13.
Sci Rep ; 13(1): 11007, 2023 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-37420084

RESUMO

To further elucidate the expression, regulation and function of Signaling Lymphocytic Activation Molecule Family (SLAMF) protein members in human monocytes and macrophages. Un-differentiated monocytic THP-1 cell (u-THP-1) and differentiated THP-1 macrophage (d-THP-1) were used as culture models in the study. Responses of cells to the differentiation agents phorbol ester (25 ng/ml) and TLR (Toll-like receptor) ligands were assessed. RT-PCR and Western blot analysis were used to determine mRNA and protein level. Pro-inflammatory cytokine mRNA expression levels and phagocytosis were used as functional markers. Data analyzed using t-test, one-way or two-way ANOVA followed by post hoc test. SLAMFs were differentially expressed in THP-1 cells. Differentiation of u-THP-1 to d-THP-1 led to significantly higher SLAMF7 mRNA and protein levels than other SLAMF. In addition, TLR stimuli increased SLAMF7 mRNA expression but not protein expression. Importantly, SLAMF7 agonist antibody and TLR ligands synergistically increased the mRNA expression levels of IL-1ß, IL-6 and TNF-α, but had no effect on phagocytosis. SLAMF7 knocked-down in d-THP-1 significantly lowered TLR-induced mRNA expressions of pro-inflammatory markers. SLAM family proteins are differentially regulated by differentiation and TLRs. SLAMF7 enhanced TLR-mediated induction of pro-inflammatory cytokines in monocytes and macrophages but not phagocytosis.


Assuntos
Macrófagos , Monócitos , Família de Moléculas de Sinalização da Ativação Linfocitária , Receptores Toll-Like , Humanos , Citocinas/metabolismo , Família , Ligantes , Lipopolissacarídeos , Macrófagos/metabolismo , Monócitos/metabolismo , RNA Mensageiro/metabolismo , Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , Receptores Toll-Like/metabolismo
14.
Front Endocrinol (Lausanne) ; 14: 1150118, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37274349

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is an important public health problem with growing numbers of NAFLD patients worldwide. Pathological conditions are different in each stage of NAFLD due to various factors. Preclinical and clinical studies provide evidence for a crucial role of immune cells in NAFLD progression. Liver-resident macrophages, kupffer cells (KCs), and monocytes-derived macrophages are the key cell types involved in the progression of NAFLD, non-alcoholic steatohepatitis (NASH), and hepatocellular carcinoma (HCC). Their unique polarization contributes to the progression of NAFLD. KCs are phagocytes with self-renewal abilities and play a role in regulating and maintaining homeostasis. Upon liver damage, KCs are activated and colonized at the site of the damaged tissue. The secretion of inflammatory cytokines and chemokines by KCs play a pivotal role in initiating NAFLD pathogenesis. This review briefly describes the role of immune cells in the immune system in NAFLD, and focuses on the pathological role and molecular pathways of KCs and recruited macrophages. In addition, the relationship between macrophages and insulin resistance is described. Finally, the latest therapeutics that target KCs and macrophages are summarized for the prevention and treatment of NAFLD.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Células de Kupffer/metabolismo , Células de Kupffer/patologia , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Macrófagos/metabolismo
15.
Pathogens ; 12(5)2023 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-37242356

RESUMO

Porcine deltacoronavirus (PDCoV) is an emerging coronavirus that causes diarrhea in nursing piglets. Since its first outbreak in the United States in 2014, this novel porcine coronavirus has been detected worldwide, including in Korea. However, no PDCoV case has been reported since the last report in 2016 in Korea. In June 2022, the Korean PDCoV strain KPDCoV-2201 was detected on a farm where sows and piglets had black tarry and watery diarrhea, respectively. We isolated the KPDCoV-2201 strain from the intestinal samples of piglets and sequenced the viral genome. Genetically, the full-length genome and spike gene of KPDCoV-2201 shared 96.9-99.2% and 95.8-98.8% nucleotide identity with other global PDCoV strains, respectively. Phylogenetic analysis suggested that KPDCoV-2201 belongs to G1b. Notably, the molecular evolutionary analysis indicated that KPDCoV-2201 evolved from a clade different from that of previously reported Korean PDCoV strains and is closely related to the emergent Peruvian and Taiwanese PDCoV strains. Furthermore, KPDCoV-2201 had one unique and two Taiwanese strain-like amino acid substitutions in the receptor-binding domain of the S1 region. Our findings suggest the possibility of transboundary transmission of the virus and expand our knowledge about the genetic diversity and evolution of PDCoV in Korea.

16.
JCI Insight ; 8(8)2023 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-37092548

RESUMO

Fibroblastic reticular cells (FRCs) play important roles in tolerance by producing laminin α4 (Lama4) and altering lymph node (LN) structure and function. The present study revealed the specific roles of extracellular matrix Lama4 in regulating LN conduits using FRC-specific KO mouse strains. FRC-derived Lama4 maintained conduit fiber integrity, as its depletion altered conduit morphology and structure and reduced homeostatic conduit flow. Lama4 regulated the lymphotoxin ß receptor (LTßR) pathway, which is critical for conduit and LN integrity. Depleting LTßR in FRCs further reduced conduits and impaired reticular fibers. Lama4 was indispensable for FRC generation and survival, as FRCs lacking Lama4 displayed reduced proliferation but upregulated senescence and apoptosis. During acute immunization, FRC Lama4 deficiency increased antigen flow through conduits. Importantly, adoptive transfer of WT FRCs to FRC Lama4-deficient mice rescued conduit structure, ameliorated Treg and chemokine distribution, and restored transplant allograft acceptance, which were all impaired by FRC Lama4 depletion. Single-cell RNA sequencing analysis of LN stromal cells indicated that the laminin and collagen signaling pathways linked crosstalk among FRC subsets and endothelial cells. This study demonstrated that FRC Lama4 is responsible for maintaining conduits by FRCs and can be harnessed to potentiate FRC-based immunomodulation.


Assuntos
Células Endoteliais , Laminina , Camundongos , Animais , Laminina/genética , Laminina/metabolismo , Linfonodos , Transdução de Sinais , Quimiocinas/metabolismo
17.
ACS Infect Dis ; 9(4): 899-915, 2023 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-36867688

RESUMO

Pathogenic bacteria have devastating impacts on human health as a result of acquired antibiotic resistance and innate tolerance. Every class of our current antibiotic arsenal was initially discovered as growth-inhibiting agents that target actively replicating (individual, free-floating) planktonic bacteria. Bacteria are notorious for utilizing a diversity of resistance mechanisms to overcome the action of conventional antibiotic therapies and forming surface-attached biofilm communities enriched in (non-replicating) persister cells. To address problems associated with pathogenic bacteria, our group is developing halogenated phenazine (HP) molecules that demonstrate potent antibacterial and biofilm-eradicating activities through a unique iron starvation mode of action. In this study, we designed, synthesized, and investigated a focused collection of carbonate-linked HP prodrugs bearing a quinone trigger to target the reductive cytoplasm of bacteria for bioactivation and subsequent HP release. The quinone moiety also contains a polyethylene glycol group, which dramatically enhances the water-solubility properties of the HP-quinone prodrugs reported herein. We found carbonate-linked HP-quinone prodrugs 11, 21-23 to demonstrate good linker stability, rapid release of the active HP warhead following dithiothreitol (reductive) treatment, and potent antibacterial activities against methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis, and Enterococcus faecalis. In addition, HP-quinone prodrug 21 induced rapid iron starvation in MRSA and S. epidermidis biofilms, illustrating prodrug action within these surface-attached communities. Overall, we are highly encouraged by these findings and believe that HP prodrugs have the potential to address antibiotic resistant and tolerant bacterial infections.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Pró-Fármacos , Humanos , Pró-Fármacos/farmacologia , Solubilidade , Antibacterianos/farmacologia , Staphylococcus epidermidis , Quinonas , Fenazinas/farmacologia , Ferro , Água
18.
Sci Rep ; 13(1): 4245, 2023 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-36918634

RESUMO

Escherichia coli (E. coli) cells are present in fecal materials that can be the main source for disease-causing agents in water. As a result, E. coli is recommended as a water quality indicator. We have developed an innovative platform to detect E. coli for monitoring water quality on-site by integrating paper-based sample preparation with nucleic acid isothermal amplification. The platform carries out bacterial lysis and DNA enrichment onto a paper pad through ball-based valves for fluid control, with no need of laboratory equipment, followed by loop-mediated isothermal amplification (LAMP) in a battery-operated coffee mug, and colorimetric detection. We have used the platform to detect E. coli in environmental water samples in about 1 h, with a limit of quantitation of 0.2 CFU/mL, and 3 copies per reaction. The platform was confirmed for detecting multiple E. coli strains, and for water samples of different salt concentrations. We validated the functions of the platform by analyzing recreational water samples collected near the Atlantic Ocean that contain different concentrations of salt and bacteria.


Assuntos
Escherichia coli , Técnicas de Amplificação de Ácido Nucleico , Escherichia coli/genética , Bactérias/genética , Oceano Atlântico
19.
J Crohns Colitis ; 17(7): 1066-1078, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-36738443

RESUMO

BACKGROUND: Rates of enrolment in clinical trials in inflammatory bowel disease [IBD] have decreased dramatically in recent years. This has led to delays, increased costs and failures to develop novel treatments. AIMS: The aim of this work is to describe the current bottlenecks of IBD clinical trial enrolment and propose solutions. METHODS: A taskforce comprising experienced IBD clinical trialists from academic centres and pharmaceutical companies involved in IBD clinical research predefined the four following levels: [1] study design, [2] investigative centre, [3] physician and [4] patient. At each level, the taskforce collectively explored the reasons for declining enrolment rates and generated an inventory of potential solutions. RESULTS: The main reasons identified included the overall increased demands for trials, the high screen failure rates, particularly in Crohn's disease, partly due to the lack of correlation between clinical and endoscopic activity, and the use of complicated endoscopic scoring systems not reflective of the totality of inflammation. In addition, complex trial protocols with restrictive eligibility criteria, increasing burden of procedures and administrative tasks enhance the need for qualified resources in study coordination. At the physician level, lack of dedicated time and training is crucial. From the patients' perspective, long washout periods from previous medications and protocol requirements not reflecting clinical practice, such as prolonged steroid management and placebo exposures, limit their participation in clinical trials. CONCLUSION: This joint effort is proposed as the basis for profound clinical trial transformation triggered by investigative centres, contract research organizations, sponsors and regulatory agencies.


Assuntos
Doença de Crohn , Doenças Inflamatórias Intestinais , Humanos , Doença de Crohn/tratamento farmacológico , Endoscopia , Inflamação , Doenças Inflamatórias Intestinais/tratamento farmacológico , Projetos de Pesquisa , Ensaios Clínicos como Assunto
20.
IEEE J Transl Eng Health Med ; 11: 145-150, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36816099

RESUMO

Increasingly complex and long-range donor organ allocation routes coupled with implementation of unmanned aerial vehicles (UAVs) have prompted investigations of the conditions affecting organs once packaged for shipment. Our group has previously demonstrated that different modes of organ transport exert unique environmental stressors, in particular vibration. Using a mouse heart transplant model, we demonstrated that vibrational forces exert tangible, cellular effects in the form of cardiomyocyte apoptosis and cytoskeletal derangement. Functionally, these changes translated into accelerated allograft loss. Notably, administration of an apoptosis inhibitor, Z-VAD-FMK, helped to ameliorate the detrimental cellular and functional effects of mechanical vibration in a dose-dependent manner. These findings constitute one of the first reports of the negative impact of transit environment on transplant outcomes, a contributing mechanism underpinning this effect, and a potential agent to prophylax against this process. Given current limitations in measuring donor organ transit environments in situ, further study is required to better characterize the impact of transport environment and to potentially improve the care of donor organs during shipment. Clinical and Translational Impact Statement: We show that apoptosis inhibitor, Z-VAD-FMK, ameliorated transport-related vibrational stress in murine heart transplants, which presents a potential therapeutic or preservation solution additive for future use in transporting donor organs.


Assuntos
Transplante de Coração , Vibração , Animais , Camundongos , Apoptose , Transplante Homólogo , Aloenxertos
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