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1.
Adv Sci (Weinh) ; : e2308662, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38666427

RESUMEN

Cancer vaccines offer a promising avenue in cancer immunotherapy by inducing systemic, tumor-specific immune responses. Tumor extracellular vesicles (TEVs) are nanoparticles naturally laden with tumor antigens, making them appealing for vaccine development. However, their inherent malignant properties from the original tumor cells limit their direct therapeutic use. This study introduces a novel approach to repurpose TEVs as potent personalized cancer vaccines. The study shows that inhibition of both YAP and autophagy not only diminishes the malignancy-associated traits of TEVs but also enhances their immunogenic attributes by enriching their load of tumor antigens and adjuvants. These revamped TEVs, termed attenuated yet immunogenically potentiated TEVs (AI-TEVs), showcase potential in inhibiting tumor growth, both as a preventive measure and a possible treatment for recurrent cancers. They prompt a tumor-specific and enduring immune memory. In addition, by showing that AI-TEVs can counteract cancer growth in a personalized vaccine approach, a potential strategy is presented for developing postoperative cancer immunotherapy that's enduring and tailored to individual patients.

2.
Pharmaceutics ; 16(3)2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38543204

RESUMEN

Small Extracellular Vesicles (sEVs) are typically 30-150 nm in diameter, produced inside cells, and released into the extracellular space. These vesicles carry RNA, DNA, proteins, and lipids that reflect the characteristics of their parent cells, enabling communication between cells and the alteration of functions or differentiation of target cells. Owing to these properties, sEVs have recently gained attention as potential carriers for functional molecules and drug delivery tools. However, their use as a therapeutic platform faces limitations, such as challenges in mass production, purity issues, and the absence of established protocols and characterization methods. To overcome these, researchers are exploring the characterization and engineering of sEVs for various applications. This review discusses the origins of sEVs and their engineering for therapeutic effects, proposing areas needing intensive study. It covers the use of cell-derived sEVs in their natural state and in engineered forms for specific purposes. Additionally, the review details the sources of sEVs and their subsequent purification methods. It also outlines the potential of therapeutic sEVs and the requirements for successful clinical trials, including methods for large-scale production and purification. Finally, we discuss the progress of ongoing clinical trials and the implications for future healthcare, offering a comprehensive overview of the latest research in sEV applications.

3.
Angew Chem Int Ed Engl ; 63(3): e202312942, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38062619

RESUMEN

The development of a small-molecule probe designed to selectively target neurons would enhance the exploration of intricate neuronal structures and functions. Among such probes, NeuO stands out as the pioneer and has gained significant traction in the field of research. Nevertheless, neither the mechanism behind neuron-selectivity nor the cellular localization has been determined. Here, we introduce NeuM, a derivative of NeuO, designed to target neuronal cell membranes. Furthermore, we elucidate the mechanism behind the selective neuronal membrane trafficking that distinguishes neurons. In an aqueous buffer, NeuM autonomously assembles into micellar structures, leading to the quenching of its fluorescence (Φ=0.001). Upon exposure to neurons, NeuM micelles were selectively internalized into neuronal endosomes via clathrin-mediated endocytosis. Through the endocytic recycling pathway, NeuM micelles integrate into neuronal membrane, dispersing fluorescent NeuM molecules in the membrane (Φ=0.61). Molecular dynamics simulations demonstrated that NeuM, in comparison to NeuO, possesses optimal lipophilicity and molecular length, facilitating its stable incorporation into phospholipid layers. The stable integration of NeuM within neuronal membrane allows the prolonged monitoring of neurons, as well as the visualization of intricate neuronal structures.


Asunto(s)
Clatrina , Micelas , Clatrina/metabolismo , Endocitosis/fisiología , Endosomas/metabolismo , Neuronas/metabolismo
4.
Small ; 19(37): e2300527, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37226374

RESUMEN

In this study, extracellular vesicles (EVs) are reimagined as more than just a cellular waste disposal system and are repurposed for cancer immunotherapy. Potent oncolytic EVs (bRSVF-EVs) loaded with misfolded proteins (MPs) are engineered, which are typically considered cellular debris. By impairing lysosomal function using bafilomycin A1 and expressing the respiratory syncytial virus F protein, a viral fusogen, MPs are successfully loaded into the EVs expressing RSVF. bRSVF-EVs preferentially transplant a xenogeneic antigen onto cancer cell membranes in a nucleolin-dependent manner, triggering an innate immune response. Furthermore, bRSVF-EV-mediated direct delivery of MPs into the cancer cell cytoplasm initiates endoplasmic reticulum stress and immunogenic cell death (ICD). This mechanism of action leads to substantial antitumor immune responses in murine tumor models. Importantly, when combined with PD-1 blockade, bRSVF-EV treatment elicits robust antitumor immunity, resulting in prolonged survival and complete remission in some cases. Overall, the findings demonstrate that utilizing tumor-targeting oncolytic EVs for direct cytoplasmic delivery of MPs to induce ICD in cancer cells represents a promising approach for enhancing durable antitumor immunity.


Asunto(s)
Vesículas Extracelulares , Neoplasias , Ratones , Animales , Vesículas Extracelulares/metabolismo , Neoplasias/patología , Citoplasma , Citosol , Inmunoterapia/métodos
5.
Biomater Sci ; 11(9): 3241-3251, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-36938935

RESUMEN

Due to the relatively long sequence, tracrRNAs are chemically less synthesizable than crRNAs, leading to limited scalability of RNA guides for CRISPR-Cas9 systems. To develop shortened versions of RNA guides with improved cost-effectiveness, we have developed a split-tracrRNA system by nicking the 67-mer tracrRNA (tracrRNA(67)). Cellular gene editing assays and in vitro DNA cleavage assays revealed that the position of the nick is critical for maintaining the activity of tracrRNA(67). TracrRNA(41 + 23), produced by nicking in stem loop 2, showed gene editing efficiency and specificity comparable to those of tracrRNA(67). Removal of the loop of stem loop 2 was further possible without compromising the efficiency and specificity when the stem duplex was stabilized via a high GC content. Binding assays and single-molecule experiments suggested that efficient split-tracrRNAs could be engineered as long as their binding affinity to Cas9 and their reaction kinetics are similar to those of tracrRNA(67).


Asunto(s)
Edición Génica , ARN Guía de Sistemas CRISPR-Cas , ARN/genética
6.
Tuberculosis (Edinb) ; 138: 102298, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36580851

RESUMEN

Ecumicin and rufomycin 4-7 disrupt protein homeostasis in Mycobacterium tuberculosis by inhibiting the proteolytic activity of the ClpC1/ClpP1/ClpP2 complex. Although these compounds target ClpC1, their effects on the ATPase activity of ClpC1 and proteolytic activity of ClpC1/ClpP1/ClpP2 vary. Herein, we explored the ClpC1 molecular dynamics with these compounds through fluorescence correlation spectroscopy. The effect of these compounds on the ATPase activity of ClpC1-cys, the recombinant protein for fluorescence labeling, and proteolytic activity of ClpC1-cys/ClpP1/ClpP2 were identical to those of native ClpC1, whereas the intermolecular dynamics of fluorescence-labelled ClpC1 were different. Treatment with up to 1 nM ecumicin increased the population of slower diffused ClpC1 components compared with ClpC1 without ecumicin. However, this population was considerably reduced when treated with 10 nM ecumicin. Rufomycin 4-7 treatment resulted in a slower diffused component of ClpC1, and the portion of this component increased in a concentration-dependent manner. Ecumicin can generate an abnormal ClpC1 component, which cannot form normal ClpC1/ClpP1/ClpP2, via two different modes. Rufomycin 4-7 only generates slower diffused ClpC1 component that is inadequate to form normal ClpC1/ClpP1/ClpP2. Overall, we demonstrate that ecumicin and rufomycin 4-7 use different action mechanisms to generate abnormal ClpC1 components that cannot couple with ClpP1/ClpP2.


Asunto(s)
Mycobacterium tuberculosis , Mycobacterium tuberculosis/genética , Proteínas Bacterianas/metabolismo , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfatasas/farmacología
7.
J Control Release ; 351: 727-738, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36162554

RESUMEN

The cluster of differentiation 47 (CD47) protein is abundantly expressed on various malignant cells and suppresses the phagocytic function of macrophages and dendritic cells. High CD47 expression levels are correlated with poor cancer survival. Antagonizing CD47 antibodies with potent antitumor effects have been developed in clinical trials, but have critical side effects, inducing anemia and thrombocytopenia. To develop a safe and potent CD47 blockade, we designed extracellular vesicles (EVs) harboring signal regulatory protein alpha (SIPRα)-EV-SIRPα (EVs that express SIPRα). EV-SIRPα showed minimal toxic effects on hematologic parameters and utilized RBCs as delivery vehicles to tumors rather than inducing anemia. EV-SIRPα inhibited ligation of residual CD47 molecules, which attribute to the EV-endocytosis-mediated CD47 depletion and steric hindrance of EV. In an immunologically cold tumor model, EV-SIRPα induced tumor-specific T-cell-mediated antitumor effects. When directly administered to the accessible lesions, EV-SIRPα monotherapy elicited an abscopal effect in the B16F10 tumor model by increasing immune cell infiltration and CD8+-mediated immunity against non-treated tumors. The combinational approach by loading doxorubicin into the EV-SIRPα dramatically reduced the tumor burden and led to 80% complete remission rate. Thus, a potent EV-based CD47 blockade that is hematologically safe, has efficient signaling blocking efficacy, and has systemic antitumor immunity against cancer is recommended.


Asunto(s)
Vesículas Extracelulares , Neoplasias , Humanos , Antígeno CD47 , Inmunoterapia , Antígenos de Diferenciación/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Macrófagos , Vesículas Extracelulares/metabolismo , Fagocitosis
8.
Front Cell Dev Biol ; 10: 822026, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35874812

RESUMEN

Recent studies with single-particle tracking in live cells have revealed that chromatin dynamics are directly affected by transcription. However, how transcription alters the chromatin movements followed by changes in the physical properties of chromatin has not been elucidated. Here, we measured diffusion characteristics of chromatin by targeting telomeric DNA repeats with CRISPR-labeling. We found that transcription inhibitors that directly block transcription factors globally increased the movements of chromatin, while the other inhibitor that blocks transcription by DNA intercalating showed an opposite effect. We hypothesized that the increased mobility of chromatin by transcription inhibition and the decreased chromatin movement by a DNA intercalating inhibitor is due to alterations in chromatin rigidity. We also tested how volume confinement of nuclear space affects chromatin movements. We observed decreased chromatin movements under osmotic pressure and with overexpressed chromatin architectural proteins that compact chromatin.

9.
Cell Rep ; 40(2): 111080, 2022 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-35830815

RESUMEN

How protein signaling networks respond to different input strengths is an important but poorly understood problem in cell biology. For example, RhoA can promote focal adhesion (FA) growth or disassembly, but how RhoA activity mediates these opposite outcomes is not clear. Here, we develop a photoswitchable RhoA guanine nucleotide exchange factor (GEF), psRhoGEF, to precisely control endogenous RhoA activity. Using this optical tool, we discover that peak FA disassembly selectively occurs upon activation of RhoA to submaximal levels. We also find that Src activation at FAs selectively occurs upon submaximal RhoA activation, identifying Src as an amplitude-dependent RhoA effector. Finally, a pharmacological Src inhibitor reverses the direction of the FA response to RhoA activation from disassembly to growth, demonstrating that Src functions to suppress FA growth upon RhoA activation. Thus, rheostatic control of RhoA activation by psRhoGEF reveals that cells can use signal amplitude to produce multiple responses to a single biochemical signal.


Asunto(s)
Factores de Intercambio de Guanina Nucleótido , Proteína de Unión al GTP rhoA , Activación Enzimática , Adhesiones Focales/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Factores de Intercambio de Guanina Nucleótido Rho/metabolismo , Transducción de Señal , Proteína de Unión al GTP rhoA/metabolismo
10.
J Immunother Cancer ; 9(7)2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34330763

RESUMEN

BACKGROUND: Statins preferentially promote tumor-specific apoptosis by depleting isoprenoid such as farnesyl pyrophosphate and geranylgeranyl pyrophosphate. However, statins have not yet been approved for clinical cancer treatment due, in part, to poor understanding of molecular determinants on statin sensitivity. Here, we investigated the potential of statins to elicit enhanced immunogenicity of KRAS-mutant (KRASmut) tumors. METHODS: The immunogenicity of treated cancer cells was determined by western blot, flow cytometry and confocal microscopy. The immunotherapeutic efficacy of mono or combination therapy using statin was assessed in KRASmut tumor models, including syngeneic colorectal cancer and genetically engineered lung and pancreatic tumors. Using NanoString analysis, we analyzed how statin influenced the gene signatures associated with the antigen presentation of dendritic cells in vivo and evaluated whether statin could induce CD8+ T-cell immunity. Multiplex immunohistochemistry was performed to better understand the complicated tumor-immune microenvironment. RESULTS: Statin-mediated inhibition of KRAS prenylation provoked severe endoplasmic reticulum (ER) stress by attenuating the anti-ER stress effect of KRAS mutation, thereby resulting in the immunogenic cell death (ICD) of KRASmut cancer cells. Moreover, statin-mediated ICD enhanced the cross-priming ability of dendritic cells, thereby provoking CD8+ T-cell immune responses against KRASmut tumors. Combination therapy using statin and oxaliplatin, an ICD inducer, significantly enhanced the immunogenicity of KRASmut tumors and promoted tumor-specific immunity in syngeneic and genetically engineered KRASmut tumor models. Along with immune-checkpoint inhibitors, the abovementioned combination therapy overcame resistance to PD-1 blockade therapies, improving the survival rate of KRASmut tumor models. CONCLUSIONS: Our findings suggest that KRAS mutation could be a molecular target for statins to elicit potent tumor-specific immunity.


Asunto(s)
Estrés del Retículo Endoplásmico/genética , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Proteínas Proto-Oncogénicas p21(ras)/efectos de los fármacos , Animales , Humanos , Masculino , Ratones , Mutación , Transfección
11.
PLoS One ; 16(2): e0247326, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33606817

RESUMEN

The quantum yield of a fluorophore is reduced when two or more identical fluorophores are in close proximity to each other. The study of protein folding or particle aggregation is can be done based on this above-mentioned phenomenon-called self-quenching. However, it is challenging to characterize the self-quenching of a fluorophore at high concentrations because of the inner filter effect, which involves depletion of excitation light and re-absorption of emission light. Herein, a novel method to directly evaluate the self-quenching behavior of fluorophores was developed. The evanescent field from an objective-type total internal reflection fluorescence (TIRF) microscope was used to reduce the path length of the excitation and emission light to ~100 nm, thereby supressing the inner filter effect. Fluorescence intensities of sulforhodamine B, fluorescein isothiocyanate (FITC), and calcein solutions with concentrations ranging from 1 µM to 50 mM were directly measured to evaluate the concentration required for 1000-fold degree of self-quenching and to examine the different mechanisms through which the fluorophores undergo self-quenching.


Asunto(s)
Colorantes Fluorescentes/química , Microscopía Fluorescente/métodos , Microscopía de Interferencia/métodos , Fluoresceína-5-Isotiocianato/química , Fluoresceínas/química , Teoría Cuántica , Rodaminas/química
12.
J Immunother Cancer ; 9(1)2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33479026

RESUMEN

BACKGROUND: Uveal melanoma (UM) is the most frequent intraocular malignancy and is resistant to immunotherapy. Nearly 50% of patients with UM develop metastatic disease, and the overall survival outcome remains very poor. Therefore, a treatment regimen that simultaneously targets primary UM and prevents metastasis is needed. Here, we suggest an immunotherapeutic strategy for UM involving a combination of local photodynamic therapy (PDT), rho-kinase (ROCK) inhibitor, and PD-1/PD-L1 immune checkpoint blockade. METHODS: The antitumor efficacy and immune response of monotreatment or combinational treatment were evaluated in B16F10-bearing syngeneic mouse models. Abscopal antitumor immune responses induced by triple-combinational treatment were validated in syngeneic bilateral B16F10 models. After each treatment, the immune profiles and functional examinations were assessed in tumors and tumor draining lymph nodes by flow cytometry, ELISA, and immunofluorescence assays. In orthotopic intraocular melanoma models, the location of the immune infiltrate in the tumor microenvironment (TME) was evaluated after each treatment by multiplex immunohistochemistry and metastatic nodules were monitored. RESULTS: PDT with Ce6-embedded nanophotosensitizer (FIC-PDT) elicited immunogenic cell death and stimulated antigen-presenting cells. In situ immunogenic clearance induced by a combination of FIC-PDT with ripasudil, a clinically approved ROCK inhibitor, stimulated antigen-presenting cells, which in turn primed tumor-specific cytotoxic T cells. Moreover, local immunogenic clearance sensitized PD-1/PD-L1 immune checkpoint blockade responses to reconstruct the TME immune phenotypes of cold tumors into hot tumors, resulting in recruitment of robust cytotoxic CD8+ T cells in the TME, propagation of systemic antitumor immunity to mediate abscopal effects, and prolonged survival. In an immune-privileged orthotopic intraocular melanoma model, even low-dose FIC-PDT and ripasudil combined with anti-PD-L1 antibody reduced the primary tumor burden and prevented metastasis. CONCLUSIONS: A combination of localized FIC-PDT and a ROCK inhibitor exerted a cancer vaccine-like function. Immunogenic clearance led to the trafficking of CD8+ T cells into the primary tumor site and sensitized the immune checkpoint blockade response to evoke systemic antitumor immunity to inhibit metastasis, one of the major challenges in UM therapy. Thus, immunogenic clearance induced by FIC-PDT and ROCK inhibitor combined with anti-PD-L1 antibody could be a potent immunotherapeutic strategy for UM.


Asunto(s)
Inhibidores de Puntos de Control Inmunológico/administración & dosificación , Isoquinolinas/administración & dosificación , Melanoma Experimental/tratamiento farmacológico , Melanoma/tratamiento farmacológico , Fotoquimioterapia/métodos , Sulfonamidas/administración & dosificación , Neoplasias de la Úvea/tratamiento farmacológico , Animales , Células Presentadoras de Antígenos/metabolismo , Línea Celular Tumoral , Sinergismo Farmacológico , Humanos , Inhibidores de Puntos de Control Inmunológico/farmacología , Isoquinolinas/farmacología , Masculino , Melanoma/inmunología , Melanoma Experimental/inmunología , Ratones , Metástasis de la Neoplasia , Sulfonamidas/farmacología , Trasplante Isogénico , Resultado del Tratamiento , Microambiente Tumoral , Neoplasias de la Úvea/inmunología , Ensayos Antitumor por Modelo de Xenoinjerto
13.
Nat Commun ; 11(1): 6033, 2020 11 27.
Artículo en Inglés | MEDLINE | ID: mdl-33247115

RESUMEN

MicroRNAs (miRNAs) are short (19-24 nt) non-coding RNAs that suppress the expression of protein coding genes at the post-transcriptional level. Differential expression profiles of miRNAs across a range of diseases have emerged as powerful biomarkers, making a reliable yet rapid profiling technique for miRNAs potentially essential in clinics. Here, we report an amplification-free multi-color single-molecule imaging technique that can profile purified endogenous miRNAs with high sensitivity, specificity, and reliability. Compared to previously reported techniques, our technique can discriminate single base mismatches and single-nucleotide 3'-tailing with low false positive rates regardless of their positions on miRNA. By preloading probes in Thermus thermophilus Argonaute (TtAgo), miRNAs detection speed is accelerated by more than 20 times. Finally, by utilizing the well-conserved linearity between single-molecule spot numbers and the target miRNA concentrations, the absolute average copy numbers of endogenous miRNA species in a single cell can be estimated. Thus our technique, Ago-FISH (Argonaute-based Fluorescence In Situ Hybridization), provides a reliable way to accurately profile various endogenous miRNAs on a single miRNA sensing chip.


Asunto(s)
MicroARNs/análisis , MicroARNs/aislamiento & purificación , Secuencia de Bases , Línea Celular , Humanos , Thermus/genética
14.
Sci Rep ; 10(1): 11623, 2020 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-32669573

RESUMEN

In neuronal exocytosis, SNARE assembly into a stable four-helix bundle drives membrane fusion. Previous studies have revealed that the SM protein Munc18-1 plays a critical role for precise SNARE assembly with the help of Munc13-1, but the underlying mechanism remains unclear. Here, we used single-molecule FRET assays with a nanodisc membrane reconstitution system to investigate the conformational dynamics of SNARE/Munc18-1 complexes in multiple intermediate steps towards the SNARE complex. We found that single Munc18-1 proteins induce the closed conformation of syntaxin-1 not only in the free syntaxin-1 but also in the t-SNARE (syntaxin-1/SNAP-25) complex. These results implicate that Munc18-1 may act as a gatekeeper for both binary and ternary SNARE complex formation by locking the syntaxin-1 in a cleft of Munc18-1. Furthermore, the kinetic analysis of the opening/closing transition reveals that the closed syntaxin-1 in the syntaxin-1/SNAP-25/Munc18-1 complex is less stable than that in the closed syntaxin-1/Munc18-1 complex, which is manifested by the infrequent closing transition, indicating that the conformational equilibrium of the ternary complex is biased toward the open conformation of syntaxin-1 compared with the binary complex.


Asunto(s)
Proteínas Munc18/fisiología , Neuronas/fisiología , Sintaxina 1/química , Animales , Exocitosis , Transferencia Resonante de Energía de Fluorescencia , Cinética , Fusión de Membrana , Mutación , Nanotecnología , Unión Proteica , Conformación Proteica , Dominios Proteicos , Ratas
15.
Nucleic Acids Res ; 47(18): e107, 2019 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-31340015

RESUMEN

Real-time visualization of single-proteins or -complexes on nucleic acid substrates is an essential tool for characterizing nucleic acid binding proteins. Here, we present a novel surface-condition independent and high-throughput single-molecule optical imaging platform called 'DNA skybridge'. The DNA skybridge is constructed in a 3D structure with 4 µm-high thin quartz barriers in a quartz slide. Each DNA end is attached to the top of the adjacent barrier, resulting in the extension and immobilization of DNA. In this 3D structure, the bottom surface is out-of-focus when the target molecules on the DNA are imaged. Moreover, the DNA skybridge itself creates a thin Gaussian light sheet beam parallel to the immobilized DNA. This dual property allows for imaging a single probe-tagged molecule moving on DNA while effectively suppressing interference with the surface and background signals from the surface.


Asunto(s)
ADN/ultraestructura , Ensayos Analíticos de Alto Rendimiento/métodos , Ácidos Nucleicos Inmovilizados/ultraestructura , Imagen Individual de Molécula/métodos , Nanotecnología/métodos , Imagen Óptica/métodos
16.
Chem Commun (Camb) ; 55(24): 3552-3555, 2019 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-30843540

RESUMEN

We demonstrated that 19 out of 20 RNA residues in the guide region of crRNA can be replaced with DNA residues with high GC-contents. The cellular activity of the chimeric crRNAs to disrupt the target gene was comparable to that of the native crRNA.


Asunto(s)
Composición de Base , Proteína 9 Asociada a CRISPR/química , Sistemas CRISPR-Cas , ADN/química , ARN Guía de Kinetoplastida/química , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , División del ADN
17.
Small ; 14(42): e1802358, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30239124

RESUMEN

Cancer cells actively release extracellular vesicles (EVs) as important carriers of cellular information to tumor microenvironments. Although the composition and quantity of the proteins contained in EVs are characterized, it remains unknown how these proteins in EVs are related to those in the original cells at the functional level. With epidermal growth factor receptor (EGFR) in lung adenocarcinoma cells as a model oncoprotein, it is studied how distinct types of EVs, microvesicles and exosomes, represent their original cells at the protein and protein-protein interaction (PPI) level. Using the recently developed single-molecule immunolabeling and co-immunoprecipitation schemes, the quantity and PPI strengths of EGFRs derived from EVs and the original lung adenocarcinoma cells are determined. It is found that the microvesicles exhibit higher correlations with the original cells than the exosomes in terms of the EGFR levels and their PPI patterns. In spite of these detailed differences between the microvesicles and exosomes, the EGFR PPI strengths measured for EVs generally show a tight correlation with those determined for the original cells. The results suggest that EGFRs contained in EVs closely reflect the cellular EGFR in terms of their downstream signaling capacity.


Asunto(s)
Receptores ErbB/química , Vesículas Extracelulares/química , Línea Celular Tumoral , Humanos , Inmunoprecipitación , Unión Proteica
18.
Nat Commun ; 9(1): 2777, 2018 07 17.
Artículo en Inglés | MEDLINE | ID: mdl-30018371

RESUMEN

Cas12a (also called Cpf1) is a representative type V-A CRISPR effector RNA-guided DNA endonuclease, which provides an alternative to type II CRISPR-Cas9 for genome editing. Previous studies have revealed that Cas12a has unique features distinct from Cas9, but the detailed mechanisms of target searching and DNA cleavage by Cas12a are still unclear. Here, we directly observe this entire process by using single-molecule fluorescence assays to study Cas12a from Acidaminococcus sp. (AsCas12a). We determine that AsCas12a ribonucleoproteins search for their on-target site by a one-dimensional diffusion along elongated DNA molecules and induce cleavage in the two DNA strands in a well-defined order, beginning with the non-target strand. Furthermore, the protospacer-adjacent motif (PAM) for AsCas12a makes only a limited contribution of DNA unwinding during R-loop formation and shows a negligible role in the process of DNA cleavage, in contrast to the Cas9 PAM.


Asunto(s)
Acidaminococcus/genética , Proteína 9 Asociada a CRISPR/genética , Sistemas CRISPR-Cas , ADN/genética , ARN Guía de Kinetoplastida/genética , Acidaminococcus/enzimología , Emparejamiento Base , Secuencia de Bases , Proteína 9 Asociada a CRISPR/metabolismo , Clonación Molecular , ADN/metabolismo , División del ADN , Escherichia coli/enzimología , Escherichia coli/genética , Edición Génica , Expresión Génica , Vectores Genéticos/química , Vectores Genéticos/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Modelos Moleculares , Conformación de Ácido Nucleico , Ácidos Nucleicos Heterodúplex , ARN Guía de Kinetoplastida/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
19.
Biomaterials ; 180: 67-77, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30025246

RESUMEN

Presentation of an endogenous bioactive ligand in its native form is a key factor in controlling and determining its bioactivity, stability, and therapeutic efficacy. In this study, we developed a novel strategy for presenting trimeric ligands on nanocages by designing, optimizing and testing based on the rational design, high-resolution structural analysis and agonistic activity assays in vitro and in vivo. We successfully designed a nanocage that presents the TNF superfamily member, TRAIL (TNF-related apoptosis-inducing ligand) in its native-like trimeric structure. The native structure of TRAIL complexes was mimicked on the resulting trimeric TRAIL-presenting nanocages (TTPNs) by inserting sufficient spacing, determined from three-dimensional structural models, to provide optimal access to the corresponding receptors. The efficacy of TTPNs as an anti-tumor agent was confirmed in preclinical studies, which revealed up to 330-fold increased affinity, 62.5-fold enhanced apoptotic activity, and improved pharmacokinetic characteristics and stability compared with the monomeric form of TRAIL (mTRAIL). In this latter context, TTPNs exhibited greater than 90% stability over 1 mo, whereas ∼50% of mTRAIL aggregated within 2 d. Consistent with their enhanced stability and ultra-high affinity for the TRAIL receptor, TTPNs effectively induced apoptosis of tumor cells in vivo, leading to effective inhibition of tumor growth. Although TRAIL was used here as a proof-of-concept, all members of the TNF superfamily share the TNF homology domain (THD) and have similar distances between ecto-domain C-termini. Thus, other TNF superfamily ligands could be genetically substituted for the TRAIL ligand on the surface of this biomimetic delivery platform.


Asunto(s)
Biomimética/métodos , Nanoestructuras/química , Ligando Inductor de Apoptosis Relacionado con TNF/química , Apoptosis , Humanos , Transducción de Señal
20.
Adv Mater ; 30(10)2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29333661

RESUMEN

A growing appreciation of the relationship between the immune system and the tumorigenesis has led to the development of strategies aimed at "re-editing" the immune system to kill tumors. Here, a novel tactic is reported for overcoming the activation-energy threshold of the immunosuppressive tumor microenvironment and mediating the delivery and presentation of tumor neoantigens to the host's immune system. This nature-derived nanocage not only efficiently presents ligands that enhance cancer cell phagocytosis, but also delivers drugs that induce immunogenic cancer cell death. The designed nanocage-therapeutics induce the release of neoantigens and danger signals in dying tumor cells, and leads to enhancement of tumor cell phagocytosis and cross-priming of tumor specific T cells by neoantigen peptide-loaded antigen-presenting cells. Potent inhibition of tumor growth and complete eradication of tumors is observed through systemic tumor-specific T cell responses in tumor draining lymph nodes and the spleen and further, infiltration of CD8+ T cells into the tumor site. Remarkably, after removal of the primary tumor, all mice treated with this nanocage-therapeutics are protected against subsequent challenge with the same tumor cells, suggesting development of lasting, tumor-specific responses. This designed nanocage-therapeutics "awakens" the host's immune system and provokes a durable systemic immune response against cancer.


Asunto(s)
Fagocitosis , Animales , Linfocitos T CD8-positivos , Muerte Celular , Células Dendríticas , Ratones , Ratones Endogámicos C57BL
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