Causas geneticas de las sorderas DFNB4: el sindrome de pendred y la sordera no sindromica eva

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Dpto. de Bioquimica. Fecha de lectura: 3 de Septiembre de 2009

Effect of Cytomegalovirus (CMV) and Ageing on T-Bet and Eomes Expression on T-Cell Subsets

The differential impact of ageing and cytomegalovirus (CMV) latent infection on human T-cell subsets remains to some extent controversial. The purpose of this study was to analyse the expression of the transcription factors T-bet and Eomes and CD57 on CD4+, CD4hiCD8lo and CD8+ T-cell subsets in healthy individuals, stratified by age and CMV serostatus. The percentage of CD4+ T-cells expressing T-bet or Eomes was very low, in particular in CD4+ T-cells from young CMV-seronegative individuals, and were higher in CMV-seropositive older individuals, in both CD57− and CD57+ CD4+ T-cells. The study of the minor peripheral blood double-positive CD4hiCD8lo T-cells showed that the percentage of these T-cells expressing both Eomes and T-bet was higher compared to CD4+ T-cells. The percentage of CD4hiCD8lo T-cells expressing T-bet was also associated with CMV seropositivity and the coexpression of Eomes, T-bet and CD57 on CD4hiCD8lo T-cells was only observed in CMV-seropositive donors, supporting the hypothesis that these cells are mature effector memory cells. The percentage of T-cells expressing Eomes and T-bet was higher in CD8+ T-cells than in CD4+ T-cells. The percentages of CD8+ T-cells expressing Eomes and T-bet increased with age in CMV-seronegative and -seropositive individuals and the percentages of CD57− CD8+ and CD57+ CD8+ T-cells coexpressing both transcription factors were similar in the different groups studied. These results support that CMV chronic infection and/or ageing are associated to the expansion of highly differentiated CD4+, CD4hiCD8lo and CD8+ T-cells that differentially express T-bet and Eomes suggesting that the expression of these transcription factors is essential for the generation and development of an effector-memory and effector T lymphocytes involved in conferring protection against chronic CMV infection

DNAM-1 and the TIGIT/PVRIG/TACTILE Axis: Novel Immune Checkpoints for Natural Killer Cell-Based Cancer Immunotherapy

Natural killer (NK) cells are lymphocytes of the innate immune response characterized by their role in the destruction of tumor cells. Activation of NK cells depend on a fine balance between activating and inhibitory signals mediated by different receptors. In recent years, a family of paired receptors that interact with ligands of the Nectin/Nectin-like (Necl) family has attracted great interest. Two of these ligands, Necl-5 (usually termed CD155 or PVR) and Nectin-2 (CD112), frequently expressed on different types of tumor cells, are recognized by a group of receptors expressed on T and NK cells that exert opposite functions after interacting with their ligands. These receptors include DNAM-1 (CD226), TIGIT, TACTILE (CD96) and the recently described PVRIG. Whereas activation through DNAM-1 after recognition of CD155 or CD112 enhances NK cell-mediated cytotoxicity against a wide range of tumor cells, TIGIT recognition of these ligands exerts an inhibitory effect on NK cells by diminishing IFN-γ production, as well as NK cell-mediated cytotoxicity. PVRIG has also been identified as an inhibitory receptor that recognizes CD112 but not CD155. However, little is known about the role of TACTILE as modulator of immune responses in humans. TACTILE control of tumor growth and metastases has been reported in murine models, and it has been suggested that it negatively regulates the anti-tumor functions mediated by DNAM-1. In NK cells from patients with solid cancer and leukemia, it has been observed a decreased expression of DNAM-1 that may shift the balance in favor to the inhibitory receptors TIGIT or PVRIG, further contributing to the diminished NK cell-mediated cytotoxic capacity observed in these patients. Analysis of DNAM-1, TIGIT, TACTILE and PVRIG on human NK cells from solid cancer or leukemia patients will clarify the role of these receptors in cancer surveillance. Overall, it can be speculated that in cancer patients the TIGIT/PVRIG pathways are upregulated and represent novel targets for checkpoint blockade immunotherapy

CD28null pro-atherogenic CD4 T-cells explain the link between CMV infection and an increased risk of Cardiovascular death

An increased risk of cardiovascular death in Cytomegalovirus (CMV)-infected individuals remains unexplained, although it might partly result from the fact that CMV infection is closely associated with the accumulation of CD28null T-cells, in particular CD28null CD4 T-cells. These cells can directly damage endothelium and precipitate cardiovascular events. However, the current paradigm holds that the accumulation of CD28null T-cells is a normal consequence of aging, whereas the link between these T-cell populations and CMV infection is explained by the increased prevalence of this infection in older people. Resolving whether CMV infection or aging triggers CD28null T-cell expansions is of critical importance because, unlike aging, CMV infection can be treated. Methods: We used multi-color flow-cytometry, antigen-specific activation assays, and HLA-typing to dissect the contributions of CMV infection and aging to the accumulation of CD28null CD4 and CD8 T-cells in CMV+ and CMV− individuals aged 19 to 94 years. Linear/logistic regression was used to test the effect of sex, age, CMV infection, and HLA-type on CD28null T-cell frequencies. Results: The median frequencies of CD28null CD4 T-cells and CD28null CD8 T-cells were >12-fold (p=0.000) but only approximately 2-fold higher (p=0.000), respectively, in CMV+ (n=136) compared with CMV− individuals (n=106). The effect of CMV infection on these T-cell subsets was confirmed by linear regression. Unexpectedly, aging contributed only marginally to an increase in CD28null T-cell frequencies, and only in CMV+ individuals. Interestingly, the presence of HLA-DRB1*0301 led to an approximately 9-fold reduction of the risk of having CD28null CD4 T-cell expansions (OR=0.108, p=0.003). Over 75% of CMV-reactive CD4 T-cells were CD28null. Conclusion: CMV infection and HLA type are major risk factors for CD28null CD4 T-cell-associated cardiovascular pathology. Increased numbers of CD28null CD8 T-cells are also associated with CMV infection, but to a lesser extent. Aging, however, makes only a negligible contribution to the expansion of these T-cell subsets, and only in the presence of CMV infection. Our results open up new avenues for risk assessment, prevention, and treatment

Characterization of the DNAM-1, TIGIT and TACTILE Axis on Circulating NK, NKT-Like and T Cell Subsets in Patients with Acute Myeloid Leukemia

Background: Acute myeloid leukemia (AML) remains a major clinical challenge due to poor overall survival, which is even more dramatic in elderly patients. TIGIT, an inhibitory receptor that interacts with CD155 and CD112 molecules, is considered as a checkpoint in T and NK cell activation. This receptor shares ligands with the co-stimulatory receptor DNAM-1 and with TACTILE. The aim of this work was to analyze the expression of DNAM-1, TIGIT and TACTILE in NK cells and T cell subsets in AML patients. Methods: We have studied 36 patients at the time of diagnosis of AML and 20 healthy volunteers. The expression of DNAM-1, TIGIT and TACTILE in NK cells and T cells, according to the expression of CD3 and CD56, was performed by flow cytometry. Results: NK cells, CD56− T cells and CD56+ T (NKT-like) cells from AML patients presented a reduced expression of DNAM-1 compared with healthy volunteers. An increased expression of TIGIT was observed in mainstream CD56− T cells. No differences were observed in the expression of TACTILE. Simplified presentation of incredibly complex evaluations (SPICE) analysis of the co-expression of DNAM-1, TIGIT and TACTILE showed an increase in NK and T cells lacking DNAM-1 and co-expressing TIGIT and TACTILE. Low percentages of DNAM-1−TIGIT+TACTILE+ NK cells and DNAM-1− TIGIT+TACTILE+ CD56− T cells were associated with a better survival of AML patients. Conclusions: The expression of DNAM-1 is reduced in NK cells and in CD4+ and CD8+ T cells from AML patients compared with those from healthy volunteers. An increased percentage of NK and T cells lacking DNAM-1 and co-expressing TIGIT and TACTILE is associated with patient survival, supporting the role of TIGIT as a novel candidate for checkpoint blockade

The use of social networking sites as an innovative tool at university: Facebook as a collaborative learning tool in Immunology

En la actualidad los docentes universitarios tienen el reto de enseñar a la conocida como “generación Y”, alumnos nacidos entre los años 1980 y 2000, los cuales no han conocido el mundo sin internet o teléfono móvil. Esto por supuesto implica que el acercamiento al conocimiento, y por tanto los modos de aprendizaje, son completamente diferentes a los de generaciones anteriores. Esto unido a la implementación de las nuevas titulaciones acordes con el proceso de convergencia europea y el sistema de créditos ECTS, y siguiendo los desafíos de la enseñanza contemplados en el Espacio Europeo de Educación Superior (EEES), hace inevitable la implementación de nuevas formas de comunicación entre los alumnos y los profesores en el ámbito Universitario. Aunque en este aspecto la mayoría de las Universidades cuentan ya con diferentes herramientas de e-Learning, su uso e implementación en algunas ocasiones puede resultar insuficiente. En este escenario, por el contrario, son muchas las posibilidades que ofrecen las redes sociales y su extenso uso entre el alumnado, quien accede generalmente con mucha frecuencia a sus perfiles y grupos, proporcionando una comunicación rápida, fácil y flexible. En el presente proyecto de innovación docente hemos combinado el uso de un grupo de Facebook con los recursos tradicionales en la docencia relativa a la asignatura de Inmunología, usando esta red social como herramienta de apoyo para compartir materiales e información. Todo ello buscando un nuevo ambiente de comunicación más directo entre alumnos y profesorado, sin por supuesto tener que sustituir las vías de comunicación formales como el correo electrónico y Moodle. Esto nos ha permitido evaluar su uso, participación y satisfacción entre el alumnado que ha participado en el proyecto.Nowadays, University teachers face the challenge of teaching the so-called “Y generation”, students born between 1980 and 2000, who haven't experienced their lives without the Internet or the mobile phone. This has a direct consequence on their approach to knowledge and, therefore, to the learning styles, which are completely different to those of former generations. This fact, together with the implementation of new degrees more in line with the European convergence process and the ECTS credit system, and following the educative challenges included in the new European Space of Higher Education (EEES), makes it necessary to implement new forms of communication between pupils and teachers in the university context. Although most universities already make use of different e-Learning tools, their use and implementation can sometimes be insufficient. In this scenery, on the contrary, the social networking sites and their extended use by students, who check their profiles and groups very often, offer a lot of possibilities, as they allow a fast, easy and flexible communication. In the present project of teaching innovation, we have combined the use of a Facebook group with the traditional resources used in Immunology, so that this social networking site becomes a support tool to share materials and information. In the same sense, we look for a new atmosphere where a more direct communication between students and teachers is possible, without avoiding the more formal forms of communication such as the email or Moodle. This has allowed us to evaluate its use, participation and satisfaction, both between the students and the teachers taking part in the project

In vitro culture with interleukin-15 leads to expression of activating receptors and recovery of natural killer cell function in acute myeloid leukemia patients

A pesar de los avances recientes en el abordaje terapéutico de las hemopatías malignas, sus pronósticos siguen siendo con frecuencia deficientes. La inmunoterapia podría abrir una nueva ventana de gran interés en este contexto. Las células asesinas naturales (NK) constituyen un área importante de investigación para las neoplasias malignas hematológicas, ya que esta subpoblación puede matar células diana de forma espontánea sin sensibilización previa, lo que representa una herramienta novedosa en el tratamiento de ellas. Se observa una función citolítica NK anormal en varias neoplasias malignas hematológicas, incluida la leucemia mieloide aguda (LMA) y los síndromes mielodisplásicos. Varios mecanismos están involucrados en esta función anormal, como la disminución de la expresión de los receptores de activación, el aumento de la expresión de los receptores inhibidores o la expresión defectuosa de los ligandos de las células NK en las células diana. Las nuevas inmunoterapias se centran en identificar factores que podrían aumentar la expresión de estos receptores activadores, para contrarrestar la expresión de los receptores inhibidores y, por lo tanto, mejorar las capacidades citotóxicas de las células NK contra las células tumorales. En este trabajo, analizamos el efecto de la interleucina (IL) -15 en la expresión de los receptores activadores de células NK que desempeñan un papel crucial en la lisis de blastos de pacientes con AML. Nuestros resultados mostraron que la IL-15 aumentó la expresión superficial de NKp30 en células NK de donantes sanos y pacientes con AML, con la consiguiente mejora de la citotoxicidad de las células NK. Además, la regulación positiva de NKp30 inducida por la IL-15 se asocia con una mejora de la maduración de las células dendríticas (DC) mieloides mediadas por NK. Las células NK cultivadas con IL-15 mostraron una regulación positiva de NKp30, que se asocia con un aumento de la actividad antitumoral y con una maduración mejorada de las DC inmaduras. En nuestro modelo in vitro, la IL-15 ejerció un gran estímulo activador que podría usarse como nueva inmunoterapia en pacientes con AML.Despite recent progress in the therapeutic approach of malignant hemopathies, their prognoses remain frequently poor. Immunotherapy could open a new window of great interest in this setting. Natural killer (NK) cells constitute an important area of research for hematologic malignancies, because this subpopulation is able to kill target cells spontaneously without previous sensitization, representing a novel tool in the treatment of them. Abnormal NK cytolytic function is observed in several hematological malignancies, including acute myeloid leukemia (AML) and myelodysplastic syndromes. Several mechanisms are involved in this abnormal function, such as decreased expression of activating receptors, increased expression of inhibitory receptors or defective expression of NK cell ligands on target cells. New immunotherapies are focused in identifying factors that could increase the expression of these activating receptors, to counteract inhibitory receptors expression, and therefore, to improve the NK cell cytotoxic capacities against tumor cells. In this work, we analyze the effect of interleukin (IL)-15 on the expression of NK cell-activating receptors that play a crucial role in the lysis of blasts from AML patients. Our results showed that IL-15 increased the surface expression of NKp30 on NK cells from healthy donors and AML patients with the consequent improvement of NK cell cytotoxicity. Besides, the upregulation of NKp30 induced by IL-15 is associated with an improvement of NK-mediated myeloid dendritic cells (DCs) maturation. NK cells cultured with IL-15 showed an upregulation of NKp30, which is associated with an increase anti-tumor activity and with an improved maturation of immature DCs. In our in vitro model, IL-15 exerted a great activating stimulus that could be used as novel immunotherapy in AML patients.• Ministerio de Economía y Competitividad. Beca SAF2013-46161-R, para Raquel Tarazona Lafarga • Junta de Extremadura. Beca IB16164, para Raquel Tarazona Lafarga • Ministerio de Salud. Beca PI13/02691 y PI16/01615, para Rafael Solana Lara • Junta de Andalucía. Ayuda CTS-208 • Junta de Extremadura y Fondos Europeos de Desarrollo Regional. Beca GR15183, para Raquel Tarazona Lafarga • Universidad de Extremadura y Fondos Europeos de Desarrollo Regional. Ayuda para Raquel Tarazona LafargapeerReviewe

EL USO DE REDES SOCIALES COMO INSTRUMENTO INNOVADOR EN LA EDUCACIÓN UNIVERSITARIA: FACEBOOK COMO HERRAMIENTA DE APRENDIZAJE COLABORATIVO EN LA ASIGNATURA DE INMUNOLOGÍA.

Nowadays, University teachers face the challenge of teaching the so-called “Y generation”, students born between 1980 and 2000, who haven't experienced their lives without the Internet or the mobile phone. This has a direct consequence on their approach to knowledge and, therefore, to the learning styles, which are completely different to those of former generations. This fact, together with the implementation of new degrees more in line with the European convergence process and the ECTS credit system, and following the educative challenges included in the new European Space of Higher Education (EEES), makes it necessary to implement new forms of communication between pupils and teachers in the university context. Although most universities already make use of different e-Learning tools, their use and implementation can sometimes be insufficient. In this scenery, on the contrary, the social networking sites and their extended use by students, who check their profiles and groups very often, offer a lot of possibilities, as they allow a fast, easy and flexible communication. In the present project of teaching innovation, we have combined the use of a Facebook group with the traditional resources used in Immunology, so that this social networking site becomes a support tool to share materials and information. In the same sense, we look for a new atmosphere where a more direct communication between students and teachers is possible, without avoiding the more formal forms of communication such as the email or Moodle. This has allowed us to evaluate its use, participation and satisfaction, both between the students and the teachers taking part in the project.En la actualidad los docentes universitarios tienen el reto de enseñar a la conocida como “generación Y”, alumnos nacidos entre los años 1980 y 2000, los cuales no han conocido el mundo sin internet o teléfono móvil. Esto por supuesto implica que el acercamiento al conocimiento, y por tanto los modos de aprendizaje, son completamente diferentes a los de generaciones anteriores. Esto unido a la implementación de las nuevas titulaciones acordes con el proceso de convergencia europea y el sistema de créditos ECTS, y siguiendo los desafíos de la enseñanza contemplados en el Espacio Europeo de Educación Superior (EEES), hace inevitable la implementación de nuevas formas de comunicación entre los alumnos y los profesores en el ámbito Universitario. Aunque en este aspecto la mayoría de las Universidades cuentan ya con diferentes herramientas de e-Learning, su uso e implementación en algunas ocasiones puede resultar insuficiente. En este escenario, por el contrario, son muchas las posibilidades que ofrecen las redes sociales y su extenso uso entre el alumnado, quien accede generalmente con mucha frecuencia a sus perfiles y grupos, proporcionando una comunicación rápida, fácil y flexible. En el presente proyecto de innovación docente hemos combinado el uso de un grupo de Facebook con los recursos tradicionales en la docencia relativa a la asignatura de Inmunología, usando esta red social como herramienta de apoyo para compartir materiales e información. Todo ello buscando un nuevo ambiente de comunicación más directo entre alumnos y profesorado, sin por supuesto tener que sustituir las vías de comunicación formales como el correo electrónico y Moodle. Esto nos ha permitido evaluar su uso, participación y satisfacción entre el alumnado que ha participado en el proyecto