RESUMEN
Clinically applied bioartificial liver (BAL) support systems are difficult to compare with regard to overall hepatocyte-specific function and clinical outcome. We compared two clinically applied BAL systems, the Modular Extracorporeal Liver Support (MELS) CellModule and the AMC-bioartificial liver (AMC-BAL) in an in vitro set-up. Both BAL systems were loaded with 10 billion freshly isolated porcine hepatocytes, cultured for 7 days and tested on days 1, 2, 4 and 7. Average decrease in hepatocyte-specific functions over 7 days was 9.7%. Three parameters differed between both bioreactors: lidocaine elimination at days 1 and 2 was significantly higher in the AMCBAL, ammonia elimination showed a significantly higher trend for the AMC-BAL over 7 days and LDH release was significantly lower at day 7 for the MELS CellModule. In conclusion, this first in vitro comparison of two clinically applied BAL systems shows comparable functional capacity over a period of 7 days.
Asunto(s)
Reactores Biológicos , Hepatocitos/fisiología , Hígado Artificial , Animales , Técnicas de Cultivo de Célula , Diseño de Equipo , Femenino , Consumo de Oxígeno , Porcinos , Factores de TiempoRESUMEN
Pathological confirmation is desired prior to high-risk surgery for suspected perihilar cholangiocarcinoma (PHC), but preoperative tissue diagnosis is limited by poor sensitivity of available techniques. This study aimed to validate whether a tumor-specific enhanced green fluorescent protein (eGFP)-expressing oncolytic virus could be used for cholangiocarcinoma (CC) cell detection. Extrahepatic CC cell lines SK-ChA-1, EGI-1, TFK-1 and control cells (primary human liver cells) were exposed to the oncolytic herpes simplex type 1 virus NV1066 for up to 24 h in adherent culture. The technique was validated for cells in suspension and cultured cells that had been exposed to crude patient bile. Optimal incubation time of the CC cells with NV1066 at a multiplicity of infection of 0.1 was determined at 6-8 h, yielding 15% eGFP-expressing cells, as measured by flow cytometry. Cells were able to survive 2-h crude bile exposure and remained capable of producing eGFP following NV1066 infection. Detection of malignant cells was possible at the highest dilution tested (10 CC cells among 2 × 105 control cells), though hampered by non-target cell autofluorescence. The technique was not applicable to cells in suspension due to insufficient eGFP production. Accordingly, as yet the technique is not suitable for standardized clinical diagnostics in PHC.
Asunto(s)
Proteínas Fluorescentes Verdes/metabolismo , Hepatocitos/metabolismo , Herpesvirus Humano 1/metabolismo , Virus Oncolíticos/metabolismo , Animales , Ácidos y Sales Biliares/farmacología , Neoplasias de los Conductos Biliares/genética , Neoplasias de los Conductos Biliares/metabolismo , Neoplasias de los Conductos Biliares/virología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Chlorocebus aethiops , Colangiocarcinoma/genética , Colangiocarcinoma/metabolismo , Colangiocarcinoma/virología , Citometría de Flujo , Proteínas Fluorescentes Verdes/genética , Hepatocitos/citología , Hepatocitos/virología , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/fisiología , Humanos , Virus Oncolíticos/genética , Virus Oncolíticos/fisiología , Células VeroRESUMEN
Bioartificial liver (BAL) systems have been developed to bridge patients with acute liver failure (ALF) to liver transplantation or liver regeneration. Clinical application of BAL systems is dependent on the supportive quality of cells used and direct availability of the whole system. Reliable transport of BAL systems from the laboratory to remote treatment centers is therefore inevitable. Subsequently, preservation conditions play a crucial role during transport of a BAL, with temperature being one of the most determining factors. In this study, we assessed the effect of subnormothermic preservation on freshly isolated porcine hepatocytes cultured in monolayer under oxygenation. Additionally, the effect of the University of Wisconsin (UW) preservation solution was compared with Williams' E (WE) culture medium at 4 degrees C. The control group was cultured for 3 days at 37 degrees C, whereas the transport groups were cultured at 4 degrees C, 15 degrees C, 21 degrees C, or 28 degrees C for 24 h at day 2. All groups were tested each day for cell damage and hepatic functions. Subnormothermic culture (i.e., 15 degrees C to 28 degrees C) for a period of 24 h did not reduce any hepatic function and did not increase cellular damage. In contrast, culture of hepatocytes in WE medium and preservation in UW solution at 4 degrees C significantly reduced hepatic function. In conclusion, freshly isolated porcine hepatocytes can be preserved for 24 h at subnormothermic temperatures as low as 15 degrees C. Future research will focus on the implementation of the AMC-BAL in an oxygenated culture medium perfusion system for transport between the laboratory and the hospital.
Asunto(s)
Reactores Biológicos , Trasplante de Células/métodos , Frío , Hepatocitos/fisiología , Preservación Biológica/métodos , Albúminas/análisis , Animales , Aspartato Aminotransferasas/análisis , Recuento de Células , Supervivencia Celular , Células Cultivadas , Hepatocitos/citología , Hepatocitos/metabolismo , L-Lactato Deshidrogenasa/análisis , Hígado Artificial , Porcinos , Temperatura , Factores de Tiempo , Urea/análisisRESUMEN
UNLABELLED: The variety of methods for measuring bioactive mass and functionality of bioartificial livers (BAL) is confusing and prevents accurate comparison of reported data. Here we present a comparison of different hepatocyte quantification methods and propose that estimation of cell pellet volume after centrifugation generates a reliable, useful and fast method. In addition a correlation is made between several function tests performed in 26 bioreactors to assess their predictive value. The ammonia eliminating capacity was found to be most predictive for other liver functions, except for lidocaine elimination as a measure of mixed function oxidase activity, which should therefore be determined separately. The oxygen consumption test proved to be an easy and predictive parameter as well. The first generation of our BAL system needed further development to assure optimal treatment of acute liver failure (ALF) patients. Changes in the porcine hepatocyte isolation method and bioreactor loading as well as changes in bioreactor configuration, including use of different materials, resulted in a significantly improved level and maintenance of in vitro BAL function. A fourfold increase in ammonia eliminating capacity, which is only reduced to 75% after seven days of culturing, offers promising prospects for further clinical application. CONCLUSION: The current second generation of our BAL and improvement of hepatocyte isolation and testing protocols have led to a significant increase in the level as well as the maintenance of hepatocyte specific function in our BAL. Finally, consensus on definition of the bioactive mass to be loaded in the bioreactor and insight in the variation and reliability of the functional and metabolic parameters enhances comparison of the different types of bioartificial livers presented in literature.
Asunto(s)
Hepatocitos/citología , Hígado Artificial , Amoníaco/metabolismo , Animales , Aspartato Aminotransferasas/metabolismo , Reactores Biológicos , Recuento de Células , Separación Celular , Centrifugación , Femenino , L-Lactato Deshidrogenasa/metabolismo , Lidocaína/metabolismo , Pruebas de Función Hepática , Consumo de Oxígeno , PorcinosRESUMEN
We developed a transfection-neutralization assay for human immunodeficiency virus type 1 (HIV-1) infectious molecular clones. In this assay CD4 negative adherent cells, transfected in microtiter plates with fixed amounts of proviral DNA of molecular HIV-1 clones, are cocultivated with CD4 positive T cell lines or primary peripheral blood mononuclear cells (PBMC) in the presence of anti-HIV-1 sera or monoclonal antibodies (MAbs). Results obtained with this technique were reproducible and compared favorably with a conventional cell-free infection inhibition assay. The transfection-neutralization assay obviates the need for virus stock preparation and, therefore, is particularly suitable for the evaluation of HIV-1 clones with slow replication kinetics and of recombinant chimeric HIV-1 clones inclined to undergo additional mutations during stock preparation. The potential value of this assay for the analysis of the specificity of neutralizing sera and MAbs was demonstrated in experiments with V3 chimeric molecular clones.