Validation of Bact/Alert automathic system in the microbiological control of cell medicinal products of Advanced Therapies

Objetivo. El Control de calidad para demostrar que un producto está libre de agentes microbianos adventicios es un aspecto clave de control de procesos y evaluación de la calidad de todas las preparaciones medicinales celulares y en la ingeniería tisular. El objetivo de este estudio es validar el sistema de detección por hemocultivo BacT / ALERT para el control microbiológico de las células mesenquimales para terapia celular, según la Farmacopea Europea (EU.PH), 2.6.27. “Control microbiológico de productos celulares” (1). Método. Para el cálculo del límite de detección las botellas de hemocultivo fueron inoculadas e incubadas con 4 réplicas de 30 UFC, 5 réplicas de 15 UFC y 5 réplicas de 6 UFC de los microorganismos en ausencia de producto celular. Se llevaron a cabo también experimentos en presencia de producto con 400.000 células mesenquimales. Este método se ha comparado con el método de referencia de Esterilidad de la EU.PH (2). La especificidad se ensayó inoculando 5 réplicas con 400.000 células mesenquimales sin microorganismos. Resultados. Todas las botellas inoculadas con células mesenquimales sin microorganismos permanecieron negativas después de 7 días de incubación. Todas las botellas inoculadas con cepas bacterianas aerobias y anaerobias fueron detectadas como positivas por el sistema, en el caso del límite inferior (6 UFC) en menos de 36 horas. Se detectaron como positivas las botellas inoculadas con Candida albicans (6 UFC) en menos de 48 horas y con Aspergillus niger (6 UFC) en menos de 72 horas. No hubo diferencias notables en el tiempo de detección entre botellas inoculadas con y sin la presencia de células mesenquimales. Conclusión: El sistema de detección de hemocultivos Bact/Alert es un método fiable para la detección de la contaminación microbiana de medicamentos a base de células mesenquimales y cumple los requisitos de la UE PH, 2.6.27, para el control microbiológico de productos celulares.Objective. Quality control to demonstrate that a product is free from adventitious microbial agents is a key aspect of process control and quality evaluation of all cell medicinal preparations and in tisular engineering. Evaluate the validation of the BacT/ALERT Blood Culture System for the microbial control of mesenchymal cells for cell therapy according European Pharmacopoeia (EU.PH), 2.6.27. “Microbiological control of cellular products” (1). Method. Blood culture bottles were challenged with 4 replica of 30 cfu, 5 replica of 15 cfu and 5 replica of 6 cfu of the test microorganisms. Test were also carried out in the presence in each contaminated culture bottle of 400.000 mesenchymal cells. This method has been compared with the reference method for Sterility of the EU.PH (2). Specificity was tested inoculating 5 replicas of broth culture media with 400.000 cells without microorganisms. Results. All bottles challenged with mesenchymal cells without microorganisms remained negative after 7 days of incubation. All inoculated bottles with aerobic and anaerobic bacterial strains were flagged as positive for the system, in case of low inoculum (6 cfu) in less than 36 hours. Candida inoculated bottles (6 cfu) were detected in less than 48 hours and Aspergillus (6 cfu) in less than 72 hours. There were no significant differences in the detection time between bottles inoculated with and without the presence of mesenchymal cells. Conclusion: The BacT/ALERT blood culture detection system and is a reliable method for detection of microbial contamination of mesenchymal cells medicinal products that fulfils the requirements of the EU PH, 2.6.27, for the microbiological control of cellular products

Pilot study of cutaneous tolerability of fibrin-agarose substitutes in healthy volunteers

Objetivos: En el presente estudio se persigue comprobar posibles reacciones adversas, derivadas del uso tópico de láminas de fibrina-agarosa en el antebrazo de voluntarios sanos. Metodología: Se llevó a cabo un estudio experimental en siete voluntarios sanos, cinco varones y dos mujeres, que no presentaban ningún tipo de lesión cutánea visible. En el antebrazo de cada voluntario se colocaron dos láminas de fibrina-agarosa de 4 cm2 . Cada lámina se cubrió con un apósito impregnado y sobre una de las láminas se aplicó pomada antibiótica con mupirocina. Ambas láminas se cubrieron finalmente con un apósito protector y se mantuvieron en contacto directo sobre la piel durante 48 horas. Resultados: Los resultados determinaron que no se detectaron reacciones adversas después de 48 horas de evolución ni en los siguientes 7 días en ningún voluntario. Se observaron diferencias entre las dos láminas implantadas en cada voluntario, ya que al retirar el apósito cubierto con pomada antibiótica, la lámina presentaba un aspecto más hidratado que la que no llevaba pomada antibiótica. Conclusiones: El uso tópico de las láminas de fibrina-agarosa en voluntarios sanos no presenta reacciones adversas del tipo irritación o alergia al aplicarse directamente por vía tópica. Aunque el tamaño muestral del estudio es limitado, sugiere que la combinación de fibrina-agarosa se presenta como el biomaterial idóneo para el desarrollo de un modelo de piel artificial humana.Purpose: This study aims to analyse possible adverse reactions resulting from the topical use of fibrin-agarose substitutes in the forearm of healthy volunteers. Methods: An experimental study was carried out in seven healthy volunteers, five males and two females, who did not have any cutaneous lesion. Two fibrin-agarose substitutes of 4 cm2 were placed in the forearm of each volunteer. Each substitute was covered with an impregnated dressing and one of the substitutes was covered with antibiotic ointment (mupirocin). Both substitutes were finally covered with a protective dressing. The substitutes were maintained for 48 hours. Results: The results determined that no adverse reactions were detected in any volunteer after 48 hours and a week of evolution. Differences were observed between the two substitutes implanted in each volunteer, since when removing the covered dressing with antibiotic ointment, the substitute presented a more hydrated appearance than the one without antibiotic cream. Conclusions: The implant of fibrin-agarose substitutes in healthy volunteers does not present irritation or allergic type adverse reactions when they applied directly topically on the skin. Although the sample size is low, the fibrin-agarose combination is presented as the biomaterial suitable for the development of an artificial human skin model

Epithelial in vitro differentiation of human mesenchymal stem cells (hMSCs) from adipose tissue (AT) and bone marrow (BM): cellular characterization and study of HLA I and II expression

AGRADECIMIENTOS Laboratorio de Citogenética del servicio de Análisis Clínicos del Hospital Universitario Virgen de las Nieves. Servicio de Análisis Clínicos (Sección de Citometría/Biopatología tumoral) del Hos- pital Universitario Virgen de las Nieves.Introducción: Las células troncales mesenquimales derivadas de tejido adiposo o médula ósea constituyen uno de los tratamientos de terapia celular más utilizados en los ensayos clínicos actuales por su capacidad inmunomoduladora. Además, por su potencial de diferenciación a células epiteliales pueden ser utilizadas en ingeniería tisular incorporadas a tejidos artificiales como la piel o córnea, sustituyendo a las células epiteliales autólogas de estos tejidos. Es necesario realizar una correcta caracterización de estas células diferenciadas y estudiar el efecto de la diferenciación en la expresión del HLA de clase I y II. Objetivos: Caracterizar y realizar los controles de calidad GMP en dos líneas de células mesenquimales troncales humanas de distintos orígenes (tejido adiposo y médula ósea) tras diferenciarlas a células epiteliales in vitro, y analizar si se modifica la expresión de los marcadores HLA I y II antes y después del proceso diferenciador. Metodología: Se ha realizado el aislamiento y expansión de las dos líneas celulares de células mesenquimales troncales a partir del tejido fuente y se ha procedido a su diferenciación in vitro a células epiteliales mediante medios de cultivos suplementados con factores de crecimiento específico. Se han realizado controles de calidad siguiendo los requerimientos de las normas de correcta fabricación y se ha estudiado por citometría de flujo la expresión de HLA tipo I y II antes y después del proceso diferenciador. Finalmente se ha comprobado mediante estudio histológico e inmunohistoquímico las características de las células diferenciadas. Resultados: Se han aislado dos líneas de células mesenquimales troncales de tejido adiposo y médula ósea que cumplen los controles de calidad propuestos. Tras el proceso diferenciador in vitro, las células mesenquimales troncales humanas no expresan marcadores HLA (I y II) importantes en la respuesta inmune, pero sí expresan débilmente proteínas relacionadas con los principales estratos epiteliales (CK5, CK6 y CK14). Conclusión: La ausencia de expresión de marcadores de HLA I y II por citometría de flujo en las células diferenciadas favorecería su uso con carácter alogénico en la construcción de piel y córneas humanas por ingeniería de tejidos, sin embargo, son necesarios más estudios que confirmen estos resultados preliminares y protocolos que optimicen el proceso diferenciador in vitro de las células mesenquimales troncales.Background: Human mesenchymal stem cells derived from adipose tissue and bone marrow are one of the most common cell therapy procedures used in recent clinical trials due to their immunomodulation capacity. Furthermore, for their epithelial differentiation potential can be used in tissue engineering, incorporated in artificial tissues such as skin and cornea, replacing autologous epithelial cells. It is necessary to make a correct cellular characterization of differentiated cells and to study the effect in HLA I and II expression. Objetives: Characterization and quality controls under GMP conditions of in vitro differentiated human mesenchymal stem cells from different sources (adipose tissue and bone marrow) to epithelial lineage, and study of HLA I and II expression before and after differentiation. Methods: Isolation and expansion of two human mesenchymal stem cells lines from their tissues of origin and in vitro differentiation to epithelial cells using culture mediums supplemented with specific growth factors. Quality controls according Good Manufacturing Practices have been made and HLA I and II expression before and after differentiation have been studied. Finally, characteristics of differentiated cells have been demonstrated by histological and immunohistochemical analysis. Results: Two human mesenchymal stem cells lines from adipose tissue and bone marrow have been isolated complying with the proposed quality controls. After in vitro differentiation, human mesenchymal stem cells do not express HLA (I and II) markers, which are important in immune response, but weakly express proteins related to main epithelial layers of human skin (CK5, CK6 and CK14). Conclusion: The absence of expression of HLA I and II by flow cytometry in differentiated cells would promote the use of them with allogenic character to construct human skin and cornea by tissue engineering, however, more studies and protocols are required to confirm these preliminary results and to optimize in vitro differentiation of human mesenchymal stem cells.FIS ISC-III and FEDER PI13/0257

Optimization of human keratinocyte culture to develop an artificial human skin model: cell alternatives as feeder layer of Advanced Therapies

Agradecimientos: Servicio de Medicina Nuclear del Complejo Hospitalario Universitario de GranadaObjetivos: En el presente estudio se persigue optimizar el cultivo de queratinocitos para desarrollar un modelo de piel artificial humana. Para ello, se utilizan como capa alimentadora células de origen humano: fibroblastos dérmicos humanos y células mesenquimales troncales derivadas de tejido adiposo. Los resultados obtenidos se comparan con los fibroblastos 3T3, capa alimentadora de origen murino utilizada desde hace décadas. Metodología: Se llevó a cabo un estudio experimental, utilizando células de origen humano y células de origen murino subletalmente irradiadas, como capa alimentadora para el establecimiento del cultivo de queratinocitos. Se evaluó la tasa de expansión celular y la tasa de duplicación en el pase celular de queratinocitos y en la recuperación celular final que se llevó a cabo a las 3 semanas de cultivo; así como el rendimiento celular y la viabilidad celular, que también se evaluaron en el procesamiento inicial. Resultados: Los resultados determinan que los fibroblastos dérmicos humanos irradiados y las células mesenquimales troncales derivadas de tejido adiposo pueden actuar como capa alimentadora promoviendo la adhesión y la expansión celular de los queratinocitos. Los fibroblastos dérmicos humanos proporcionan resultados equiparables a los obtenidos con los fibroblastos 3T3 murinos. Conclusiones: Los fibroblastos dérmicos humanos irradiados proporcionan una capa alimentadora funcional que permite la expansión in vitro de manera eficaz de los queratinocitos que se van a utilizar con fines clínicos para el desarrollo de un modelo de piel artificial humana.Purpose: This study aims to optimize keratinocyte culture to develop an artificial human skin model. For this purpose, human cells are used as feeder layer: human dermal fibroblasts and adipose derived mesenchymal stem cells. The results obtained are compared with 3T3 fibroblasts, murine feeder layer used for decades. Methods: We conducted an experimental study using human and murine sub-lethally irradiated cells as feeder layer for the establishment of keratinocyte culture. Cell expansion rate and doubling rate were evaluated in the keratinocyte cell passage and in the final cell recovery (was carried out at 3 weeks). The yield and viability of keratinocytes were also evaluated in the initial processing. Results: The results determine that irradiated human dermal fibroblasts and irradiated adipose derived mesenchymal stem cells can act as feeder layer promoting adhesion and expansion of keratinocytes. Human dermal fibroblasts provide comparable results to those obtained with murine 3T3 fibroblasts. Conclusions: Irradiated human dermal fibroblasts provide a functional feeder layer which allows effectively in vitro expansion of keratinocytes to be used for clinical purposes for the development of an artificial human skin model

Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

Common variants in Alzheimer’s disease and risk stratification by polygenic risk scores

Genetic discoveries of Alzheimer’s disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer’s disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer’s disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer’s disease

New insights into the genetic etiology of Alzheimer’s disease and related dementias

Characterization of the genetic landscape of Alzheimer’s disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‘proxy’ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

New insights into the genetic etiology of Alzheimer’s disease and related dementias

Characterization of the genetic landscape of Alzheimer’s disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‘proxy’ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele