Implicación de células citotóxicas en reacciones de hipersensibilidad retardada a medicamentos y regulación de la producción de IFN-gamma mediada por células NK

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de lectura: 23-02-200

An Extract from the Plant Deschampsia antarctica

The Antarctic plant Deschampsia antarctica (DA) is able to survive in extreme conditions thanks to its special mechanism of protection against environmental aggressions. In this work, we investigated whether an aqueous extract of the plant (EDA) retains some of its defensive properties and is able to protect our skin against common external oxidants. We evaluated EDA over young human fibroblasts and exposed to H2O2, and we measured cell proliferation, viability, and senescence-associated β-galactosidase (SA-β-Gal). We also tested the expression of several senescence-associated proteins including sirtuin1, lamin A/C, the replicative protein PCNA, and the redox protein thioredoxin 2. We found that EDA promoted per se cell proliferation and viability and increased the expression of anti-senescence-related markers. Then, we selected a dose of H2O2 as an inductor of senescence in human fibroblasts, and we found that an EDA treatment 24 h prior H2O2 exposure increased fibroblast proliferation. EDA significantly inhibited the increase in SA-β-Gal levels induced by H2O2 and promoted the expression of sirtuin 1 and lamin A/C proteins. Altogether, these results suggest that EDA protects human fibroblasts from cellular senescence induced by H2O2, pointing to this compound as a potential therapeutic agent to treat or prevent skin senescence

Type I interferon regulates the survival and functionality of B cells in rainbow trout

This work was supported by the European Research Council (ERC Consolidator Grant No. 2016 725061 TEMUBLYM), by the Spanish Ministry of Science, Innovation and Universities (project AGL2017-85494-C2-1-R) and by the Comunidad de Madrid (Grant No. 2016-T1/BIO-1672).Peer reviewedPublisher PD

Unexpected role for the human Cx37 C1019T polymorphism in tumour cell proliferation

Connexins are a large family of proteins that form gap junction channels allowing exchange of ions and small metabolites between neighboring cells. They have been implicated in pathological processes such as tumourigenesis in which they may act as tumour suppressors. A polymorphism in the human connexin37 (Cx37) gene (C1019T), resulting in a non-conservative amino acid change in the regulatory C-terminus (CT) of the Cx37 protein (P319S) has been suggested to be implicated in predisposition to angiosarcomas. In this study, we have used communication-deficient HeLa and SK-HEP-1 cells transfected with Cx37-319S, Cx37-319P or empty vector. We showed that the expression of Cx37-319P limited proliferation of HeLa and SK-HEP-1 cells, whereas Cx37-319S expression was without effect. Using an in vitro kinase assay, we demonstrated phosphorylation of Cx37 CT by glycogen synthase kinase-3 (GSK-3), a kinase known to be implicated in cell proliferation and cancer. GSK-3-induced phosphorylation was associated with reduced gap junctional intercellular communication (GJIC) as measured by microinjection of the tracer neurobiotin. Inhibition of GSK-3 by LiCl or SB415286 reduced phosphorylation of Cx37-319P and increased GJIC. This latter effect on GJIC involved the beta and not the alpha isoform of GSK-3. In contrast, GSK-3 inhibitors were without effect on HeLa cells expressing Cx37-319S. In conclusion, our data indicate functional effects of the Cx37 C1019T polymorphism on GJIC that might contribute to tumour cell growt

Endothelial Cx40 limits myocardial ischaemia/reperfusion injury in mice

Aims Gap junctions are indispensable for the function of heart and blood vessels by providing electrical coupling and direct cell-to-cell transfer of small signalling molecules. Gap junction channels between neighbouring cells are composed of 12 connexins (Cx). Changes in Cx43 expression, localization, and channel properties in cardiomyocytes contribute to infarction and reperfusion injury of the heart. It is increasingly recognized that deleterious consequences of ischaemia/reperfusion (IR) are modulated by the inflammatory response and endothelial function. The role of the endothelial connexins, i.e. Cx40 and Cx37, in cardiac IR injury is, however, not known. Methods and results Following 30 min ischaemia and 24 h reperfusion, we found a significant increase in myocardial infarct size in mice with endothelial-specific deletion of Cx40 (Cx40del), but not in Cx37-deficient mice. The cardioprotective effect of endothelial Cx40 was associated with a decrease in neutrophil infiltration. Moreover, beneficial effects of endothelial Cx40 were not observed in isolated Langendorff-perfused hearts, suggesting direct involvement of endothelial-leucocyte interactions in the cardiac injury. Single-dose administration of methotrexate, a CD73 activator, reduced infarct size and neutrophil infiltration into the infarcted myocardium in Cx40del but not in control mice. Similar to Cx40del mice, CD73-deficient mice showed increased sensitivity to cardiac IR injury, which could not be conversed by methotrexate. Conclusion Endothelial Cx40, but not Cx37, is implicated in resistance of the heart to IR injury by activation of the CD73 pathway. Thus, the Cx40-CD73 axis may represent an interesting target for controlling reperfusion damage associated with revascularization in coronary diseas

CD38 Defines a Subset of B Cells in Rainbow Trout Kidney With High IgM Secreting Capacities

Funding Information: This work was supported by the European Research Council (ERC Consolidator Grant 2016 725061 TEMUBLYM) and by the Comunidad de Madrid (grant 2016-T1/BIO-1672).Peer reviewedPublisher PD

CpG Oligodeoxynucleotides Modulate Innate and Adaptive Functions of IgM+ B Cells in Rainbow Trout

Oligodeoxynucleotides (ODN) containing unmethylated CpG motifs have been widely postulated as vaccine adjuvants both in mammals and teleost fish. However, to date, the effects that CpGs provoke on cells of the adaptive immune system remain mostly unexplored in fish. Given that rainbow trout (Oncorhynchus mykiss) IgM+ B cells from spleen and blood transcribe high levels of toll like receptor 9 (TLR9), the receptor responsible for CpG detection in mammals, in the current work, we have investigated the effects of CpGs on both spleen and blood IgM+ B cells from this species. CpGs were shown to exert strong proliferative effects on both spleen and blood IgM+ B cells, also increasing their survival. The fact that CpGs increase the size of IgM+ B cells, reduce the expression of surface IgM and IgD and up-regulate the number of IgM-secreting cells strongly suggest that IgM+ B cells differentiate to plasmablasts/plasma cells in response to CpG stimulation. Additionally, CpGs were shown to modulate the antigen presenting capacities of trout IgM+ B cells through an increased surface MHC II expression and transcriptional up-regulation of co-stimulatory molecules, although in this case, significant differences were observed between the effects exerted on spleen and blood cells. Similarly, differences were observed between spleen and blood IgM+ B cells when CpG stimulation was combined with B cell receptor (BCR) cross-linking. Finally, CpGs were also shown to affect innate functions of teleost IgM+ B cells such as their phagocytic capacity. These results demonstrate that CpGs regulate many adaptive and innate functions of teleost B cells, supporting their inclusion as adjuvants in novel vaccine formulations

Non-myeloablative autologous haematopoietic stem cell transplantation expands regulatory cells and depletes IL-17 producing mucosal-associated invariant T cells in multiple sclerosis

Autologous haematopoietic stem cell transplantation has been tried as one experimental strategy for the treatment of patients with aggressive multiple sclerosis refractory to other immunotherapies. The procedure is aimed at ablating and repopulating the immune repertoire by sequentially mobilizing and harvesting haematopoietic stem cells, administering an immunosuppressive conditioning regimen, and re-infusing the autologous haematopoietic cell product. ‘Non-myeloablative' conditioning regimens to achieve lymphocytic ablation without marrow suppression have been proposed to improve safety and tolerability. One trial with non-myeloablative autologous haematopoietic stem cell transplantation reported clinical improvement and inflammatory stabilization in treated patients with highly active multiple sclerosis. The aim of the present study was to understand the changes in the reconstituted immune repertoire bearing potential relevance to its mode of action. Peripheral blood was obtained from 12 patients with multiple sclerosis participating in the aforementioned trial and longitudinally followed for 2 years. We examined the phenotype and function of peripheral blood lymphocytes by cell surface or intracellular staining and multi-colour fluorescence activated cell sorting alone or in combination with proliferation assays. During immune reconstitution post-transplantation we observed significant though transient increases in the proportion of CD4+FoxP3+ T cells and CD56high natural killer cell subsets, which are cell subsets associated with immunoregulatory function. CD8+CD57+ cytotoxic T cells were persistently increased after therapy and were able to suppress CD4+ T cell proliferation with variable potency. In contrast, a CD161high proinflammatory CD8+ T cell subset was depleted at all time-points post-transplantation. Phenotypic characterization revealed that the CD161highCD8+ T cells were mucosal-associated invariant T cells, a novel cell population originating in the gut mucosa but expressing the central nervous system-homing receptor CCR6. Detection of mucosal-associated invariant T cells in post-mortem multiple sclerosis brain white matter active lesions confirmed their involvement in the disease pathology. Intracellular cytokine staining demonstrated interferon γ and interleukin 17 production and lack of interleukin 10 production, a pro-inflammatory profile. Mucosal-associated invariant T cell frequency did not change in patients treated with interferon β; and was more depleted after autologous haematopoietic stem cell transplantation than in patients who had received high-dose cyclophosphamide (n = 7) or alemtuzumab (n = 21) treatment alone, suggesting an additive or synergistic effect of the conditioning regime components. We propose that a favourably modified balance of regulatory and pro-inflammatory lymphocytes underlies the suppression of central nervous system inflammation in patients with multiple sclerosis following non-myeloablative autologous haematopoietic stem cell transplantation with a conditioning regimen consisting of cyclophosphamide and alemtuzuma

Antología I. Taller Literario Mariano Lebrón Saviñón

Nan Chevalier (biografía): Reynaldo Paulino (Nan) Chevalier nació en Puerto Plata, República Dominicana, en 1965. Se licenció en letras y en psicología en la Universidad Autónoma de Santo Domingo (UASD), donde cursó un posgrado en lengua y literatura y una maestría en literatura hispanoamericana. Fue director de la Escuela de Letras de la UASD; en la actualidad es director del Departamento de Español de UNAPEC. Ha publicado Las formas que retornan (poemas), Editora Búho, 1998; Ave de mal agüero (poemas), Letra Gráfica, 2003; La segunda señal (cuentos), Letra Gráfica, 2003; Ciudad de mis ruinas (novela), Letra Gráfica, 2007; Antihéroes onettianos: habitantes de proyectos fallidos (Colección Premios FUNGLODE 2011-Ensayo), Serigraf, 2012; El muñeco de trapos (Colección Premios FUNGLODE 2011-Cuento), Serigraf, 2012; El hombre que parecía esconderse (novela), Alfaguara, 2014; El domador de fieras y otros nanorrelatos (minificción), Editora Nacional, 2015; La recámara aislante del tiempo (cuentos), Búho, 2014, y Viaje sin retorno desde un puerto fantasma (novela), Búho, 2015. Sus textos han sido incluidos en revistas y antologías, como Juego de imágenes: la nueva poesía dominicana, de Frank Martínez y Néstor Rodríguez (editores); La espiral sonora (Antología del poema en prosa en Santo Domingo 1890-2000), Basilio Belliard (compilador); Poemas de último minuto, Mónica Volonteri (compiladora); Al filo del agua: XX años de poesía dominicana, Miguel Antonio Jiménez (compilador); Vendimia Primera, Luis R. Santos (compilador), Colección de cuentos del Banco Central de la República Dominicana; Puente de palabras: Compilación de cuentos costarricenses y dominicanos, Avelino Stanley (compilador); Alforja, Revista de Poesía, Hernán Lara Zavala (editor), México; Coloquios, José Manuel Fernández Pequeño (editor); Vetas, Clodomiro Moquete (editor); Voci da Quisqueya, María Antonieta Ferro (compiladora), Italia; El cuerno de oro (cuentos sobre infidelidades), Eulogio Javier (compilador), Guatemala, 2008; La ciudad en nosotros, Soledad Álvarez (compiladora); País Cultural, Basilio Belliard (editor), 2009; Algarero cultural, número 18, Javier Payeros/Valentín Amaro (editores), Guatemala; Ruptura del límite, Avelino Stanley (compilador), Bogotá; Sieteculebras. Revista andina de cultura, Perú; El viaje, Luis Reinaldo Pérez (editor); y Los nuevos caníbales, Puerto Rico, 2015. Ha recibido, entre otros, el Premio FUNGLODE de Cuento (2011); y el Premio Único del III Concurso Nacional de Minificción, Ministerio de Cultura de la República Dominicana (2013).La vida interna de un taller literario está llena de aventuras espirituales e intelectuales. Sus integrantes se embarcan en la lectura de importantes textos literarios pertenecientes tanto a la tradición nacional y la propia lengua como a tradiciones de otros países y de otros idiomas. Esas lecturas, que son compartidas, van enriqueciendo la vida gracias a las originales historias, al dominio lingüístico y a la complejidad de las visiones puestas en juego en cada obra. Es así como todos los integrantes van madurando sus particulares concepciones del mundo y van aprendiendo a educar su íntima búsqueda de la belleza. Búsqueda que va fortaleciéndose a medida que cada tallerista va encontrándose a sí mismo a través de esos juegos de espejos que son los libros. Suele suceder, entonces, que la propia voz comience a tomar forma y que demande expresarse por unos cauces que les sean originarios. Es cuando surgen las obras, las florescencias, las creaciones que ayudan a forjar para uno mismo un lugar habitable en el mundo. Esta antología es precisamente la primera muestra pública de las voces emergentes de los miembros del Taller Literario Mariano Lebrón Saviñón, uno de los órganos culturales de la Universidad APEC. La componen textos llenos de vida y pasión, de una mirada maravillada a esta existencia convulsa, que puede a veces ser turbulenta, pero que siempre es hermosa. Son textos para olvidarse de sí y perderse en la inquietante lumbre que ofrecen