Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Glia ; 70(5): 935-960, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35092321

RESUMEN

A key pathological process in Parkinson's disease (PD) is the transneuronal spreading of α-synuclein. Alpha-synuclein (α-syn) is a presynaptic protein that, in PD, forms pathological inclusions. Other hallmarks of PD include neurodegeneration and microgliosis in susceptible brain regions. Whether it is primarily transneuronal spreading of α-syn particles, inclusion formation, or other mechanisms, such as inflammation, that cause neurodegeneration in PD is unclear. We used a model of spreading of α-syn induced by striatal injection of α-syn preformed fibrils into the mouse striatum to address this question. We performed quantitative analysis for α-syn inclusions, neurodegeneration, and microgliosis in different brain regions, and generated gene expression profiles of the ventral midbrain, at two different timepoints after disease induction. We observed significant neurodegeneration and microgliosis in brain regions not only with, but also without α-syn inclusions. We also observed prominent microgliosis in injured brain regions that did not correlate with neurodegeneration nor with inclusion load. Using longitudinal gene expression profiling, we observed early gene expression changes, linked to neuroinflammation, that preceded neurodegeneration, indicating an active role of microglia in this process. Altered gene pathways overlapped with those typical of PD. Our observations indicate that α-syn inclusion formation is not the major driver in the early phases of PD-like neurodegeneration, but that microglia, activated by diffusible, oligomeric α-syn, may play a key role in this process. Our findings uncover new features of α-syn induced pathologies, in particular microgliosis, and point to the necessity for a broader view of the process of α-syn spreading.


Asunto(s)
Enfermedad de Parkinson , alfa-Sinucleína/metabolismo , Animales , Modelos Animales de Enfermedad , Ratones , Microglía/metabolismo , Enfermedades Neuroinflamatorias , Enfermedad de Parkinson/genética , alfa-Sinucleína/genética
2.
Urol Int ; 106(10): 1061-1067, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34130302

RESUMEN

INTRODUCTION: The impact of teratomatous elements in orchiectomy specimens of metastasized testicular germ cell tumors (TGCT) regarding oncological outcome is still unclear. METHODS: We performed a retrospective analysis including 146 patients with metastasized TGCT analysing patient characteristics. RESULTS: Twenty-six (18%) of all patients showed teratomatous elements in the orchiectomy specimens. TGCT with teratomatous elements showed a significantly higher frequency of clinical-stage 2C-3 disease (73 vs. 49%, p = 0.031), visceral metastases (58 vs. 32%, p = 0.015), and poor prognosis (p = 0.011) than TGCT without teratomatous elements. Teratoma-containing TGCT revealed a significantly higher rate of post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND, 54 vs. 32%, p = 0.041), with teratomatous elements being more often present in the PC-RPLND specimens (43 vs. 11%, p = 0.020) than nonteratoma-containing primaries. In the Kaplan-Meier estimates, the presence of teratomatous elements in orchiectomy specimens was associated with a significantly reduced relapse-free survival (RFS) (p = 0.049) during a median follow-up of 36 months (10-115.5). CONCLUSIONS: The presence of teratomatous elements in orchiectomy specimens is associated with an advanced tumor stage, worse treatment response as well as a reduced RFS in metastasized TGCT. Consequently, the presence of teratomatous elements might act as a reliable stratification tool for treatment decision in TGCT patients.


Asunto(s)
Neoplasias de Células Germinales y Embrionarias , Teratoma , Neoplasias Testiculares , Humanos , Escisión del Ganglio Linfático , Metástasis Linfática , Masculino , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Neoplasias de Células Germinales y Embrionarias/patología , Neoplasias de Células Germinales y Embrionarias/cirugía , Orquiectomía , Espacio Retroperitoneal , Estudios Retrospectivos , Teratoma/cirugía , Neoplasias Testiculares/patología
3.
Invest New Drugs ; 39(4): 914-927, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33492639

RESUMEN

Introduction Differentiation therapy is a promising strategy for cancer treatment. The translationally controlled tumor protein (TCTP) is an encouraging target in this context. By now, this field of research is still at its infancy, which motivated us to perform a large-scale screening for the identification of novel ligands of TCTP. We studied the binding mode and the effect of TCTP blockade on the cell cycle in different cancer cell lines. Methods Based on the ZINC-database, we performed virtual screening of 2,556,750 compounds to analyze the binding of small molecules to TCTP. The in silico results were confirmed by microscale thermophoresis. The effect of the new ligand molecules was investigated on cancer cell survival, flow cytometric cell cycle analysis and protein expression by Western blotting and co-immunoprecipitation in MOLT-4, MDA-MB-231, SK-OV-3 and MCF-7 cells. Results Large-scale virtual screening by PyRx combined with molecular docking by AutoDock4 revealed five candidate compounds. By microscale thermophoresis, ZINC10157406 (6-(4-fluorophenyl)-2-[(8-methoxy-4-methyl-2-quinazolinyl)amino]-4(3H)-pyrimidinone) was identified as TCTP ligand with a KD of 0.87 ± 0.38. ZINC10157406 revealed growth inhibitory effects and caused G0/G1 cell cycle arrest in MOLT-4, SK-OV-3 and MCF-7 cells. ZINC10157406 (2 × IC50) downregulated TCTP expression by 86.70 ± 0.44% and upregulated p53 expression by 177.60 ± 12.46%. We validated ZINC10157406 binding to the p53 interaction site of TCTP and replacing p53 by co-immunoprecipitation. Discussion ZINC10157406 was identified as potent ligand of TCTP by in silico and in vitro methods. The compound bound to TCTP with a considerably higher affinity compared to artesunate as known TCTP inhibitor. We were able to demonstrate the effect of TCTP blockade at the p53 binding site, i.e. expression of TCTP decreased, whereas p53 expression increased. This effect was accompanied by a dose-dependent decrease of CDK2, CDK4, CDK, cyclin D1 and cyclin D3 causing a G0/G1 cell cycle arrest in MOLT-4, SK-OV-3 and MCF-7 cells. Our findings are supposed to stimulate further research on TCTP-specific small molecules for differentiation therapy in oncology.


Asunto(s)
Antineoplásicos/farmacología , Drogas en Investigación/farmacología , Neoplasias/tratamiento farmacológico , Proteína Tumoral Controlada Traslacionalmente 1/antagonistas & inhibidores , Antineoplásicos/administración & dosificación , Artesunato/farmacología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Simulación por Computador , Bases de Datos Farmacéuticas , Relación Dosis-Respuesta a Droga , Drogas en Investigación/administración & dosificación , Humanos , Ligandos , Simulación del Acoplamiento Molecular , Neoplasias/patología , Proteína Tumoral Controlada Traslacionalmente 1/metabolismo
4.
J Vasc Interv Radiol ; 30(9): 1452-1458, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31371137

RESUMEN

PURPOSE: To evaluate the radiation dose in patients undergoing prostatic artery embolization (PAE) using cone-beam CT and 3-dimensional (3D) guidance software. MATERIALS AND METHODS: In this single-center retrospective study, 100 patients with benign prostatic hyperplasia (mean prostate volume, 83.6 mL ± 44.2; 69.4 ± 9.6 years of age; body mass index, 26.5 ± 4.2) were treated using PAE between October 2016 and April 2018. Informed consent was obtained from all participants included in the study. All patients received at least 1 intraprocedural cone-beam CT per side for evaluation of the vessel anatomy and software rendering of 3D guidance for catheter guidance. Digital subtraction angiography (DSA) was performed in the distal branches only. The total dose area product (DAP), along with the DAP attributed to fluoroscopy, DSA, and cone-beam CT, were assessed. RESULTS: Bilateral embolization was achieved in 83 patients (83%). The average total DAP was 134.4 Gy ⋅ cm2 ± 69.5 (range, 44.7-410.9 Gy ⋅ cm2). Fluoroscopy, DSA, and cone-beam CT accounted for 35.5 Gy ⋅ cm2 ± 21.3 (range, 8.6-148.6 Gy ⋅ cm2) or 26.4% (percentage of total DAP), 58.2 Gy ⋅ cm2 ± 48.3 (range, 10.3-309.3 Gy ⋅ cm2) or 43.3%, and 40.7 Gy ⋅ cm2 ± 14.5 (range, 15.9-86.3 Gy ⋅ cm2) or 30.3%, respectively. Average procedure time was 89.4 ± 27.0 minutes, and the average fluoroscopy time was 30.9 ± 12.2 minutes. CONCLUSIONS: Intraprocedural cone-beam CT in combination with 3D guidance software allows for identification and catheterization of the prostatic artery in PAE. Furthermore, the results of this trial indicate that this study protocol may lead to a low overall radiation dose.


Asunto(s)
Arterias/diagnóstico por imagen , Angiografía por Tomografía Computarizada , Tomografía Computarizada de Haz Cónico , Embolización Terapéutica , Imagenología Tridimensional , Próstata/irrigación sanguínea , Hiperplasia Prostática/terapia , Dosis de Radiación , Radiografía Intervencional/métodos , Programas Informáticos , Anciano , Angiografía por Tomografía Computarizada/efectos adversos , Tomografía Computarizada de Haz Cónico/efectos adversos , Embolización Terapéutica/efectos adversos , Alemania , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Hiperplasia Prostática/diagnóstico por imagen , Exposición a la Radiación , Radiografía Intervencional/efectos adversos , Estudios Retrospectivos , Medición de Riesgo , Factores de Tiempo
5.
J Biol Chem ; 292(10): 4185-4197, 2017 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-28154179

RESUMEN

To improve our understanding of properties that confer successful inhibition of chemokines in vivo, we analyzed anti-murine CXCL10 monoclonal antibodies (mAb) having different characteristics. 1B6 displayed potent inhibition of cell recruitment in vitro with an IC50 of 0.5 nm but demonstrated little efficacy in various animal models of human disease. On the contrary, 1F11 showed efficacy in several models of inflammation yet was less potent at inhibiting chemotaxis in vitro with an IC50 of 21 nm Furthermore, we observed that 1B6 displayed a rapid dose-dependent clearance (t½ 10-60 h) in contrast to 1F11, which presented a dose-proportional pharmacokinetic profile and a half-life of 12 days. Moreover, 1B6 recognized glycosaminoglycan (GAG)-bound CXCL10, resulting in target-mediated clearance, which was corroborated using CXCL10-deficient mice. In contrast to 1B6, 1F11 inhibited the interaction of CXCL10 with GAGs, did not recognize GAG-bound CXCL10, and did not display target-mediated drug disposition. Confirming previous animal studies, 1B6 was poor at reversing glycemia in a model of type 1 diabetes, whereas 1F11 induced early and prolonged control of diabetes. Furthermore, when using 1A4, a subsequently generated anti-mCXCL10 mAb that shares the property with 1F11 of being unable to recognize CXCL10 immobilized on GAG, we observed a similar superior control of diabetes as compared with 1B6. We therefore concluded that targeting chemokines with antibodies such as 1B6 that recognize the more abundant GAG-bound form of the chemokine may not be the optimal strategy to achieve disease control.


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Neutralizantes/administración & dosificación , Quimiocina CXCL10/antagonistas & inhibidores , Diabetes Mellitus Experimental/prevención & control , Diabetes Mellitus Tipo 1/prevención & control , Endotelio Vascular/metabolismo , Glicosaminoglicanos/metabolismo , Animales , Anticuerpos Monoclonales/farmacocinética , Células Cultivadas , Quimiocina CXCL10/inmunología , Quimiocina CXCL10/metabolismo , Quimiotaxis de Leucocito/fisiología , Cricetinae , Diabetes Mellitus Experimental/inmunología , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 1/inmunología , Diabetes Mellitus Tipo 1/patología , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/inmunología , Femenino , Humanos , Ratones , Ratones Endogámicos C57BL , Distribución Tisular
6.
Pharmacol Res ; 129: 262-273, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29179999

RESUMEN

Alzheimer's disease (AD) is the most prevalent form of dementia. The exact pathophysiology of this disease remains incompletely understood and safe and effective therapies are required. AD is highly correlated with neuroinflammation and oxidative stress in brain causing neuronal loss. Nuclear factor of activated B-cells (NF-κB) is involved in physiological inflammatory processes and thus representing a promising target for inflammation-based AD therapy. Phytochemicals are able to interfere with the NF-κB pathway. They inhibit the phosphorylation or the ubiquitination of signaling molecules, and thus, inhibit the degradation of IκB. The translocation of NF-κB to the nucleus and subsequent transcription of pro-inflammatory cytokines are inhibited by the actions of phytochemicals. Additionally, natural compounds preventing the interaction of NF-κB can block NF-κB's transcriptional activity by inhibiting its binding to target DNA. Many polyphenols including curcumin, resveratrol, pterostilbene, punicalagin, macranthoin G, salidroside, 4-O-methylhonokiol, lycopene, genistein, obovatol and gallic acid were reported as potent NF-κB inhibitors for AD treatment. Several alkaloids such as galantamine, glaucocalyxin B, tetrandrine, berberine, oridonin, anatabine have been shown anti-inflammatory effects in AD models in vitro as well as in vivo. Besides, vitamins, tanshinone IIA, artemisinin, dihydroasparagusic acid, geniposide, xanthoceraside, l-theranine, 1,8-cineole and paeoniflorin were described as promising NF-κB inhibitors. In conclusion, natural products from plants represent interesting candidates for AD treatment. They may qualify as promising compounds for the development of derivatives providing enhanced pharmacological features.


Asunto(s)
Alcaloides/farmacología , Enfermedad de Alzheimer/tratamiento farmacológico , FN-kappa B/antagonistas & inhibidores , Fitoquímicos/farmacología , Polifenoles/farmacología , Animales , Humanos , Vitaminas/farmacología
7.
Mol Ther ; 25(2): 523-533, 2017 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-28153099

RESUMEN

CD47 is a ubiquitously expressed immune checkpoint receptor that is often upregulated in cancer. CD47 interacts with its counter-receptor SIRPα on macrophages and other myeloid cells to inhibit cancer cell phagocytosis and drive immune evasion. To overcome tolerability and "antigen sink" issues arising from widespread CD47 expression, we generated dual-targeting bispecific antibodies that selectively block the CD47-SIRPα interaction on malignant cells expressing a specific tumor-associated antigen; e.g., CD19 or mesothelin. These bispecific κλ bodies are fully human, native IgG1 molecules, combining tumor targeting and selective CD47 blockade with immune activating mechanisms mediated by the Fc portion of the antibody. CD47-neutralizing κλ bodies efficiently kill cancer cells in vitro and in vivo but interact only weakly with healthy cells expressing physiological levels of CD47. Accordingly, a κλ body administered to non-human primates showed a typical IgG pharmacokinetic profile and was well tolerated. Importantly, κλ bodies preserve their tumoricidal capabilities in the presence of a CD47 antigen sink. Thus, dual-targeting κλ bodies allow for efficacious yet safe targeting of CD47 in cancer. Such a bispecific design could be applied to limit the extent of neutralization of other ubiquitously expressed therapeutic targets.


Asunto(s)
Anticuerpos Biespecíficos/farmacología , Antígeno CD47/metabolismo , Animales , Anticuerpos Biespecíficos/inmunología , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Antígenos de Neoplasias/inmunología , Antineoplásicos/farmacología , Antígeno CD47/inmunología , Línea Celular Tumoral , Modelos Animales de Enfermedad , Femenino , Humanos , Mesotelina , Ratones , Ratones Endogámicos NOD , Ratones SCID , Terapia Molecular Dirigida , Neoplasias/tratamiento farmacológico , Neoplasias/inmunología , Neoplasias/metabolismo , Fagocitosis/inmunología , Unión Proteica/inmunología , Ensayos Antitumor por Modelo de Xenoinjerto
8.
Phytother Res ; 32(2): 185-198, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29044858

RESUMEN

Medicinal plants have always had great value for the human population due to their valuable constituents and potential bioactivities. The objective of this review is to present an updated overview of an important medicinal plant genus Nepeta L., from the family Lamiaceae, revealing its traditional utilization, biological activity, phytoconstituents, and mechanisms of action. For this purpose, a literature survey was carried out by using SciFinder, ScienceDirect, Scopus, PubMed, and Web of Science followed by a revision of the bibliographies of the related articles. We have described and analyzed the role of plants in drug discovery and the importance of Nepeta species. Information on the utilization purposes of Nepeta species in folk medicine has been emphasized, and scientific studies on the biological effects and secondary metabolites are addressed. Nepeta species are characterized by terpenoid-type compounds and phenolic constituents, which exert several activities such as an antimicrobial, repellent against major pathogen vector mosquitoes, insecticide, larvicide against Anopheles stephensi, cytotoxic anticarcinogen, antioxidant, anticonvulsant, analgesic, anti-inflammatory agent, and antidepressant, revealing its importance in medicinal and agricultural fields. On the basis of numerous studies, the Nepeta genus demonstrates remarkable therapeutic effects against various diseases. However, clinical studies are warranted to confirm preclinical findings.


Asunto(s)
Medicina Tradicional/métodos , Nepeta/química , Fitoterapia/métodos , Plantas Medicinales/efectos de los fármacos , Humanos
9.
PLoS Pathog ; 11(11): e1005276, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26587982

RESUMEN

Arenaviruses such as Lassa virus (LASV) can cause severe hemorrhagic fever in humans. As a major impediment to vaccine development, delayed and weak neutralizing antibody (nAb) responses represent a unifying characteristic of both natural infection and all vaccine candidates tested to date. To investigate the mechanisms underlying arenavirus nAb evasion we engineered several arenavirus envelope-chimeric viruses and glycan-deficient variants thereof. We performed neutralization tests with sera from experimentally infected mice and from LASV-convalescent human patients. NAb response kinetics in mice correlated inversely with the N-linked glycan density in the arenavirus envelope protein's globular head. Additionally and most intriguingly, infection with fully glycosylated viruses elicited antibodies, which neutralized predominantly their glycan-deficient variants, both in mice and humans. Binding studies with monoclonal antibodies indicated that envelope glycans reduced nAb on-rate, occupancy and thereby counteracted virus neutralization. In infected mice, the envelope glycan shield promoted protracted viral infection by preventing its timely elimination by the ensuing antibody response. Thus, arenavirus envelope glycosylation impairs the protective efficacy rather than the induction of nAbs, and thereby prevents efficient antibody-mediated virus control. This immune evasion mechanism imposes limitations on antibody-based vaccination and convalescent serum therapy.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Arenavirus/inmunología , Fiebres Hemorrágicas Virales/inmunología , Polisacáridos/inmunología , Animales , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Humanos , Ratones Endogámicos C57BL , Datos de Secuencia Molecular
10.
Arch Toxicol ; 90(10): 2497-511, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27325308

RESUMEN

Primary human hepatocytes (PHH) are still considered as gold standard for investigation of in vitro metabolism and hepatotoxicity in pharmaceutical research. It has been shown that the three-dimensional (3D) cultivation of PHH in a sandwich configuration between two layers of extracellular matrix (ECM) enables the hepatocytes to adhere three dimensionally leading to formation of in vivo like cell-cell contacts and cell-matrix interactions. The aim of the present study was to investigate the influence of different ECM compositions on morphology, cellular arrangement and bile canaliculi formation as well as bile excretion processes in PHH sandwich cultures systematically. Freshly isolated PHH were cultured for 6 days between two ECM layers made of collagen and/or Matrigel in four different combinations. The cultures were investigated by phase contrast microscopy and immunofluorescence analysis with respect to cell-cell connections, repolarization as well as bile canaliculi formation. The influence of the ECM composition on cell activity and viability was measured using the XTT assay and a fluorescent dead or alive assay. Finally, the bile canalicular transport was analyzed by live cell imaging to monitor the secretion and accumulation of the fluorescent substance CDF in bile canaliculi. Using collagen and Matrigel in different compositions in sandwich cultures of hepatocytes, we observed differences in morphology, cellular arrangement and cell activity of PHH in dependence of the ECM composition. Sandwich-cultured hepatocytes with an underlay of collagen seem to represent the best in vivo tissue architecture in terms of formation of trabecular cell arrangement. Cultures overlaid with collagen were characterized by the formation of abundant bile canaliculi, while the bile canaliculi network in hepatocytes cultured on a layer of Matrigel and overlaid with collagen showed the most branched and stable canalicular network. All cultures showed a time-dependent leakage of CDF from the bile canaliculi into the culture supernatant with variations in dependence on the used matrix combination. In conclusion, the results of this study show that the choice of ECM has an impact on the morphology, cell assembly and bile canaliculi formation in PHH sandwich cultures. The morphology and the multicellular arrangement were essentially influenced by the underlaying matrix, while bile excretion and leakage of sandwich-cultured hepatocytes were mainly influenced by the overlay matrix. Leaking and damaged bile canaliculi could be a limitation of the investigated sandwich culture models in long-term excretion studies.


Asunto(s)
Canalículos Biliares/metabolismo , Bilis/metabolismo , Matriz Extracelular/metabolismo , Hepatocitos/metabolismo , Cultivo Primario de Células/métodos , Anciano , Anciano de 80 o más Años , Transporte Biológico , Adhesión Celular , Polaridad Celular , Supervivencia Celular , Células Cultivadas , Colágeno/química , Combinación de Medicamentos , Femenino , Hepatocitos/citología , Humanos , Laminina/química , Masculino , Microscopía de Contraste de Fase , Persona de Mediana Edad , Proteoglicanos/química
11.
Biochim Biophys Acta ; 1843(12): 2913-25, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25229427

RESUMEN

Deoxyribose-phosphate aldolase (EC 4.1.2.4), which converts 2-deoxy-d-ribose-5-phosphate into glyceraldehyde-3-phosphate and acetaldehyde, belongs to the core metabolism of living organisms. It was previously shown that human cells harbor deoxyribose phosphate aldolase activity but the protein responsible of this activity has never been formally identified. This study provides the first experimental evidence that DERA, which is mainly expressed in lung, liver and colon, is the human deoxyribose phosphate aldolase. Among human cell lines, the highest DERA mRNA level and deoxyribose phosphate aldolase activity were observed in liver-derived Huh-7 cells. DERA was shown to interact with the known stress granule component YBX1 and to be recruited to stress granules after oxidative or mitochondrial stress. In addition, cells in which DERA expression was down-regulated using shRNA formed fewer stress granules and were more prone to apoptosis after clotrimazole stress, suggesting the importance of DERA for stress granule formation. Furthermore, the expression of DERA was shown to permit cells in which mitochondrial ATP production was abolished to make use of extracellular deoxyinosine to maintain ATP levels. This study unraveled a previously undescribed pathway which may allow cells with high deoxyribose-phosphate aldolase activity, such as liver cells, to minimize or delay stress-induced damage by producing energy through deoxynucleoside degradation.

12.
Methods ; 60(1): 99-110, 2013 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-23500657

RESUMEN

The use of next generation sequencing (NGS) for the analysis of antibody sequences both in phage display libraries and during in vitro selection processes has become increasingly popular in the last few years. Here, our methods developed for DNA preparation, sequencing and data analysis are presented. A key parameter has also been to develop new software designed for high throughput antibody sequence analysis that is used in combination with publicly available tools. As an example of our methods, we provide data from the extensive analysis of five scFv libraries generated using different heavy chain CDR3 diversification strategies. The results not only confirm that the library designs were correct but also reveal differences in quality not easily identified by standard DNA sequencing approaches. The very large number of reads permits extensive sequence coverage after the selection process. Furthermore, as samples can be multiplexed, costs decrease and more information is gained per NGS run. Using examples of results obtained post phage display selections against two antigens, frequency and clustering analysis identified novel antibody fragments that were then shown to be specific for the target antigen. In summary, the methods described here demonstrate how NGS analysis enhances quality control of complex antibody libraries as well as facilitates the antibody discovery process.


Asunto(s)
Anticuerpos/química , Bacteriófagos/genética , Descubrimiento de Drogas , Secuenciación de Nucleótidos de Alto Rendimiento , Biblioteca de Péptidos
13.
MAbs ; 16(1): 2362432, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38849989

RESUMEN

In contrast to natural antibodies that rely mainly on the heavy chain to establish contacts with their cognate antigen, we have developed a bispecific antibody format in which the light chain (LC) drives antigen binding and specificity. To better understand epitope-paratope interactions in this context, we determined the X-ray crystallographic structures of an antigen binding fragment (Fab) in complex with human CD47 and another Fab in complex with human PD-L1. These Fabs contain a κ-LC and a λ-LC, respectively, which are paired with an identical heavy chain (HC). The structural analysis of these complexes revealed the dominant contribution of the LCs to antigen binding, but also that the common HC provides some contacts in both CD47 and PD-L1 Fab complexes. The anti-CD47 Fab was affinity optimized by diversifying complementary-determining regions of the LC followed by phage display selections. Using homology modeling, the contributions of the amino acid modification to the affinity increase were analyzed. Our results demonstrate that, despite a less prominent role in natural antibodies, the LC can mediate high affinity binding to different antigens and neutralize their biological function. Importantly, Fabs containing a common variable heavy (VH) domain enable the generation of bispecific antibodies retaining a truly native structure, maximizing their therapeutic potential.


Asunto(s)
Anticuerpos Biespecíficos , Antígeno B7-H1 , Antígeno CD47 , Fragmentos Fab de Inmunoglobulinas , Anticuerpos Biespecíficos/química , Anticuerpos Biespecíficos/inmunología , Humanos , Antígeno CD47/inmunología , Antígeno CD47/química , Fragmentos Fab de Inmunoglobulinas/química , Fragmentos Fab de Inmunoglobulinas/inmunología , Antígeno B7-H1/inmunología , Antígeno B7-H1/química , Antígeno B7-H1/antagonistas & inhibidores , Cristalografía por Rayos X , Cadenas Ligeras de Inmunoglobulina/química , Cadenas Ligeras de Inmunoglobulina/inmunología , Modelos Moleculares
14.
J Biol Chem ; 287(2): 1458-67, 2012 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-22041899

RESUMEN

Dual-specific antibodies are characterized by an antigen-combining site mediating specific interactions with two different antigens. We have generated five dual-specific single chain variable fragments (scFv) that neutralize the activity of the two chemokines, CXCL9 and CXCL10, to bind to their receptor CXCR3. To better understand how these dual-specific scFvs bind these two chemokines that only share a 37% sequence identity, we mapped their epitopes on human CXCL9 and CXCL10 and identified serine 13 (Ser(13)) as a critical residue. It is conserved between the two chemokines but not in the third ligand for CXCR3, CXCL11. Furthermore, Ser(13) is exposed in the tetrameric structure of CXCL10, which is consistent with our finding that the scFvs are able to bind to CXCL9 and CXCL10 immobilized on glycosaminoglycans. Overall, the data indicate that these dual-specific scFvs bind to a conserved surface involved in CXCR3 receptor interaction for CXCL10 and CXCL9. Thus, structural mimicry between the two targets is likely to be responsible for the observed dual specificity of these antibody fragments.


Asunto(s)
Especificidad de Anticuerpos , Quimiocina CXCL10/química , Quimiocina CXCL9/química , Imitación Molecular , Anticuerpos de Cadena Única/química , Animales , Quimiocina CXCL10/genética , Quimiocina CXCL10/inmunología , Quimiocina CXCL11/química , Quimiocina CXCL11/genética , Quimiocina CXCL11/inmunología , Quimiocina CXCL9/genética , Quimiocina CXCL9/inmunología , Humanos , Macaca fascicularis , Macaca mulatta , Ratones , Conejos , Receptores CXCR3/química , Receptores CXCR3/genética , Receptores CXCR3/inmunología , Anticuerpos de Cadena Única/genética , Anticuerpos de Cadena Única/inmunología
15.
Eur Heart J ; 33(15): 1964-74, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21606075

RESUMEN

AIMS: The chemokine CCL5 plays a critical role as neutrophil and macrophage activator do in atherosclerosis and myocardial infarction. Thus, we investigated whether the treatment with a neutralizing monoclonal antibody (mAb) to mouse CCL5 would provide therapeutic benefit when provoking a coronary-associated ischaemic event. METHODS AND RESULTS: C57Bl/6 mice were submitted to left coronary artery permanent ligature. Then, various parameters were monitored for up to 21 days. At5 min and 3 days after coronary occlusion, mice received one intravenous injection of the rat anti-mouse CCL5 mAb or isotype IgG control. Infarct size was assessed histologically and by measuring serum cardiac troponin I levels. Kinetics of CCL5 tissue expression, leucocyte infiltration, matrix metalloproteinase (MMP) levels, and collagen deposition were histologically assessed. Serum chemokine levels were measured by enzyme-linked immunosorbent assay. Cardiac function and dimensions were assessed by magnetic resonance imaging (MRI). Chronic ischaemia increased both circulating and intracardiac levels of CCL5. At 24 h, treatment with the anti-CCL5 mAb resulted in a smaller infarct size and reduced circulating levels of chemokines. This effect was associated with reduction of neutrophil and macrophage infiltration within the infarcted myocardium. After 3 days of chronic ischaemia, anti-CCL5 mAb treatment reduced cardiac MMP-9. At 7 days, collagen content was significantly lower. At 21 days, neutralizing CCL5 improved mouse survival, cardiac myocyte size, and cardiac function. CONCLUSION: Treatment with anti-CCL5 mAb significantly reduced both infarct size and post-infarction heart failure in a mouse model of chronic cardiac ischaemia. Cardioprotective effects were associated with the reduction of leucocyte recruitment within infarcted hearts.


Asunto(s)
Anticuerpos Monoclonales/farmacología , Quimiocina CCL5/fisiología , Insuficiencia Cardíaca/patología , Infarto del Miocardio/patología , Animales , Peso Corporal/fisiología , Quimiocina CCL5/antagonistas & inhibidores , Quimiocina CCL5/inmunología , Quimiotaxis de Leucocito/fisiología , Enfermedad Crónica , Colágeno/metabolismo , Ligadura , Macrófagos/fisiología , Metaloproteinasa 8 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones , Ratones Endogámicos C57BL , Monocitos/fisiología , Isquemia Miocárdica/metabolismo , Reperfusión Miocárdica/métodos , Infiltración Neutrófila/fisiología , Neutrófilos/fisiología , Tamaño de los Órganos/fisiología , Tasa de Supervivencia
16.
Anticancer Res ; 43(6): 2741-2747, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37247924

RESUMEN

BACKGROUND/AIM: The robotic retroperitoneal approach for renal mass surgery was introduced in 2018 at the Department of Urology in the clinic of Leverkusen, Germany. Clinical criteria for the choice of the access site (trans- vs. retroperitoneal) are not clearly defined. The aim of this study was to explore the learning curve and the impact of the access site on clinical outcome, in order to elucidate which preoperative clinical criteria should be taken into account when choosing the renal approach site. PATIENTS AND METHODS: This retrospective study included 107 patients who underwent robotic tumor surgery between June 2018 and March 2022 at the Department of Urology in the Clinic of Leverkusen, Germany. Data from 86 patients with transperitoneal robotic surgery of the kidney and 21 patients with retroperitoneal access were available for analysis. We evaluated the data of patients in a trans- and a retroperitoneal access group. The preoperative clinical data included anthropomorphic data, the Body Mass Index (BMI) as well as the Preoperative Aspects and Dimensions Used for Anatomical Classification of Renal Masses (PADUA) - score. Intraoperative and postoperative data such as blood loss, clamping time, renal function and the learning curve of the surgeons was used to evaluate the outcomes of the two groups. RESULTS: Operation time in the retroperitoneal group was significantly shorter (p=0.015). Operation-specific variables showed no significant difference between the two groups. PADUA score and hilar clamping time showed no difference (p=0.345 and p=0.130, respectively). The learning curve in the retroperitoneal access group unveiled a noticeable difference in the experience and mastery of the involved surgeons. CONCLUSION: Mastery of the retroperitoneal approach is readily possible for surgeons with previous experience in robotic renal surgery without compromising the operative morbidity. The PADUA-score seems most suitable as a preoperative clinical criterion for choosing the renal approach site.


Asunto(s)
Neoplasias Renales , Laparoscopía , Procedimientos Quirúrgicos Robotizados , Humanos , Procedimientos Quirúrgicos Robotizados/métodos , Neoplasias Renales/cirugía , Neoplasias Renales/patología , Estudios Retrospectivos , Curva de Aprendizaje , Resultado del Tratamiento , Nefrectomía/métodos , Espacio Retroperitoneal/cirugía , Espacio Retroperitoneal/patología , Laparoscopía/métodos
17.
Biochem Biophys Res Commun ; 417(1): 29-34, 2012 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-22133680

RESUMEN

BACKGROUND: We investigated the role of the programmed cell death 4 (PDCD4) tumor suppressor gene in specimens of transitional cell carcinoma and of healthy individuals. METHODS: PDCD4 immunohistochemical expression was investigated in 294 cases in histologically proven transitional cell carcinoma in different tumorous stages (28 controls, 122 non-muscle invasive urothelial carcinoma, stages Tis-T1, 119 invasive transitional cell carcinoma stages T2-T4 and 25 metastases). MiR-21 expression, an important PDCD4 regulator, was assessed with real-time PCR analysis and showed inverse correlation to tissue PDCD4 expression. RESULTS: Nuclear and cytoplasmatic PDCD4 immunostaining decreased significantly with histopathological progression of the tumor (p<0001). Controls showed strong nuclear and cytoplasmatic immunohistochemical staining. MiR-21 up regulation in tissue corresponded to PDCD4 suppression. CONCLUSIONS: These data support a decisive role for PDCD4 down regulation in transitional cell carcinoma and confirm miR-21 as a negative regulator for PDCD4. Additionally, PDCD4 immunohistochemical staining turns out to be a possible diagnostic marker for transitional cell carcinoma.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/biosíntesis , Carcinoma de Células Transicionales/metabolismo , MicroARNs/biosíntesis , Proteínas de Unión al ARN/biosíntesis , Neoplasias Urológicas/metabolismo , Urotelio/metabolismo , Anciano , Anciano de 80 o más Años , Carcinoma de Células Transicionales/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Neoplasias Urológicas/patología , Urotelio/patología
18.
J Immunol ; 185(4): 2544-54, 2010 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-20644170

RESUMEN

Chemokines are key regulators of leukocyte trafficking and play a crucial role under homeostatic and inflammatory conditions. Because chemokines are involved in multiple pathologies, they represent an attractive class of therapeutic targets. However, because of the redundancy of this system, neutralizing a single chemokine may be insufficient to achieve therapeutic benefit. Our strategy was to use a Fc-fusion recombinant protein form of the poxvirus-derived viral CC chemokine inhibitor protein (vCCI-Fc) that has the ability to specifically bind to multiple CC chemokines and neutralize their activity. In this study, we demonstrate first that, in vivo, vCCI-Fc prevents CC chemokine-dependent migration of macrophages into inflamed tissue of carageenan-challenged mice. We next studied this effect of inhibiting CC chemokine activity in a model more relevant to human disease, collagen-induced arthritis. Mice receiving vCCI-Fc revealed a striking retention of splenocytes, including activated and IFN-gamma-secreting CD4(+) and CD8(+) T cells, that was associated with a concomitant decrease of cells in the draining lymph nodes. These phenomena resulted in a significant decrease in the incidence of disease and a reduction in clinical score, joint inflammation, and cartilage destruction as compared with mice receiving isotype control. Taken together, these results define a role for CC chemokines in the control of disease, as interfering with their function leads to a previously unappreciated role of controlling inflammatory cell trafficking in and out of secondary lymphoid organs.


Asunto(s)
Artritis Experimental/inmunología , Quimiocinas CC/inmunología , Inflamación/inmunología , Proteínas Recombinantes de Fusión/inmunología , Animales , Artritis Experimental/prevención & control , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Movimiento Celular/inmunología , Quimiocinas CC/antagonistas & inhibidores , Quimiocinas CC/metabolismo , Femenino , Citometría de Flujo , Humanos , Fragmentos Fc de Inmunoglobulinas/genética , Fragmentos Fc de Inmunoglobulinas/metabolismo , Inflamación/prevención & control , Interferón gamma/inmunología , Interferón gamma/metabolismo , Recuento de Linfocitos , Macrófagos/citología , Macrófagos/inmunología , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Unión Proteica , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Recombinantes de Fusión/farmacología , Bazo/citología , Bazo/inmunología , Bazo/metabolismo , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Linfocitos T/metabolismo , Virus Vaccinia/genética , Virus Vaccinia/metabolismo , Proteínas Virales/genética , Proteínas Virales/metabolismo
19.
Cancers (Basel) ; 14(6)2022 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-35326629

RESUMEN

This study aimed to compare the diagnostic performance of [18F]PSMA-1007 positron emission tomography/computed tomography (PET/CT) (18F-PSMA) and [68Ga]Ga-PSMA-11 PET/CT (68Ga-PSMA) by identifying prostate-specific antigen (PSA) threshold levels for optimal detecting recurrent prostate cancer (PC) and to compare both methods. Retrospectively, the study included 264 patients. The performances of 18F-PSMA and 68Ga-PSMA in relation to the pre-scan PSA were assessed by receiver operating characteristic (ROC) curve. 18F-PSMA showed PC-lesions in 87.5% (112/128 patients), while 68Ga-PSMA identified them in 88.9% (121/136). For 18F-PSMA biochemical recurrent (BCR) patients treated with radical prostatectomy (78/128, patient group: F-RP), a PSA of 1.08 ng/mL was found to be the optimal cut-off level for predicting positive and negative scans (AUC = 0.821; 95%, CI: 0.710−0.932), while for prostatectomized 68Ga-PSMA BCR-patients (89/136, patient group: Ga-RP), the cut-off was 1.84 ng/mL (AUC = 0.588; 95%, CI: 0.410−0.766). In patients with PSA < 1.08 ng/mL (F-RP) 76.3% and <1.84 ng/mL (Ga-RP) 78.6% scans were positive, whereas patients with PSA ≥ 1.08 ng/mL (F-RP) or 1.84 ng/mL (Ga-RP) had positive scan results in 100% and 91.5% (p < 0.001/p = 0.085). The identified PSA thresholds for PSMA-mappable PC lesions in BCR-patients (RP) showed a better separation for 18F-PSMA with regard to the distinguishing of positive and negative PC-lesions compared to 68Ga-PSMA. However, the two PSMA PET/CT tracers gave similar overall findings.

20.
Exp Neurol ; 347: 113881, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34597681

RESUMEN

Hypo-excitability was reported in the peri-infarct tissue following stroke, an effect counteracted by a blockage of α5-GABAA receptors in adult rodents. Our present study aims to evaluate the effect of a selective α5-GABAA receptor antagonist, S 44819, in stroke in juvenile animals. We have set up and characterized an original model of transient ischemic stroke in 28 day-old Sprague-Dawley rats (45-min occlusion of the middle cerebral artery by intraluminal suture). In this model, S 44819 (1, 3 and 10 mg/kg, b.i.d) was orally administered from day 3 to day 16 after stroke onset. Sensorimotor recovery was assessed on day 1, day 9 and day 16 after stroke onset. Results show that rats treated with S 44819 at the doses of 3 and 10 mg/kg displayed a significant improvement of the neurological deficits (neuroscore) on day 9 and day 16, when compared with animals treated with vehicle. Grip-test data analysis reveals that rats treated with S 44819 at the dose of 3 mg/kg displayed a better recovery on day 9 and day 16. These results are in agreement with those previously observed in adult rats, demonstrating that targeting α5-GABAA receptors improves neurological recovery after stroke in juvenile rats.


Asunto(s)
Benzodiazepinas/farmacología , Antagonistas de Receptores de GABA-A/farmacología , Oxazoles/farmacología , Recuperación de la Función/efectos de los fármacos , Accidente Cerebrovascular/fisiopatología , Animales , Masculino , Ratas , Ratas Sprague-Dawley
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA