Articles by Obdulio García-Nicolás in JoVE
Inyección de contraste percutánea guiada por ecocardiografía intramiocárdica y entrega de celular en un modelo preclínico grande Alejandro Giraldo*1, Jesús Talavera López*2, Maria Josefa Fernandez-Del-Palacio2, Obdulio García-Nicolás3,4, Juan Seva4, Gavin Brooks1, José María Moraleda5 1Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, 2Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad de Murcia, 3Institute of Virology and Immunology (IVI), 4Departamento de Anatomía y Anatomía Comparada, Facultad de Veterinaria, Universidad de Murcia, 5Unidad de Trasplante Hematopoyético y Terapia Celular, Departamento de Hematología, Hospital Universitario Virgen de la Arrixaca, IMIB, Universidad de Murcia Nuevas estrategias terapéuticas en medicina regenerativa cardiaca requieren extensos y detallados estudios en modelos animales preclínicos grandes antes que pueden ser considerados para el uso en seres humanos. Aquí, demostramos una técnica de inyección de contraste percutánea guiada por ecocardiografía intramiocárdica en conejos, que es valiosa para la hipótesis que prueba la eficacia de estas nuevas terapias.
Other articles by Obdulio García-Nicolás on PubMed
Japanese Encephalitis Virus Tropism in Experimentally Infected Pigs Veterinary Research. | Pubmed ID: 26911997 Pigs are considered to be the main amplifying host for Japanese encephalitis virus (JEV), and their infection can correlate with human cases of disease. Despite their importance in the ecology of the virus as it relates to human cases of encephalitis, the pathogenesis of JEV in pigs remains obscure. In the present study, the localization and kinetics of virus replication were investigated in various tissues after experimental intravenous infection of pigs. The data demonstrate a rapid and broad spreading of the virus to the central nervous system (CNS) and various other organs. A particular tropism of JEV in pigs not only to the CNS but also for secondary lymphoid tissue, in particular the tonsils with the overall highest viral loads, was observed. In this organ, even 11 days post infection, the latest time point of the experiment, no apparent decrease in viral RNA loads and live virus was found despite the presence of a neutralizing antibody response. This was also well beyond the clinical and viremic phase. These results are of significance for the pathogenesis of JEV, and call for further experimental studies focusing on the cellular source and duration of virus replication in pigs.
Heterogeneous Antigenic Properties of the Porcine Reproductive and Respiratory Syndrome Virus Nucleocapsid Veterinary Research. | Pubmed ID: 27871316 Porcine reproductive and respiratory syndrome virus (PRRSV) is an arterivirus responsible for a widespread contagious disease of domestic pigs with high economic impact. Switzerland is one of the rare PRRSV-free countries in Europe, although sporadic outbreaks have occurred in the past. The PRRSV isolate IVI-1173 from the short outbreak in Switzerland in 2012 was entirely sequenced, and a functional full-length cDNA clone was constructed. Genetic and antigenic characterization of IVI-1173 revealed the importance of amino acid 90 of the nucleocapsid protein N as part of a conformational epitope. IVI-1173 was not detected by SDOW17, a monoclonal antibody against N widely used to detect PRRSV-infected cells. Substitution of alanine at position 90 of N [N(A90)] with a threonine [N(T90)] restored reactivity of vIVI1173-N(T90) to SDOW17 completely. The relevance of this amino acid for the conformational SDOW17 epitope of PRRSV N was further confirmed by the opposite substitution in a functional cDNA clone of the genotype 2 isolate RVB-581. Finally, N proteins from ten genotype 1 strains differing from threonine at position 90 were analysed for reactivity with SDOW17. N(A90) totally disrupted or severely affected the epitope in 7 out of 8 strains tested. Based on these findings, 225 genotype 1 strains were screened for the prevalence of N(A90). N(A90) is rare in classical subtype 1 and in subtype 3 strains, but is frequent in Russian subtype 1 (70%) and in subtype 2 (45%) isolates. In conclusion, this study highlights the variable antigenic properties of N among genotype 1 PRRSV strains.
A Japanese Encephalitis Virus Vaccine Inducing Antibodies Strongly Enhancing In Vitro Infection Is Protective in Pigs Viruses. | Pubmed ID: 28531165 The Japanese encephalitis virus (JEV) is responsible for zoonotic severe viral encephalitis transmitted by Culex mosquitoes. Although birds are reservoirs, pigs play a role as amplifying hosts, and are affected in particular through reproductive failure. Here, we show that a lentiviral JEV vector, expressing JEV prM and E proteins (TRIP/JEV.prME), but not JEV infection induces strong antibody-dependent enhancement (ADE) activities for infection of macrophages. Such antibodies strongly promoted infection via Fc receptors. ADE was found at both neutralizing and non-neutralizing serum dilutions. Nevertheless, in vivo JEV challenge of pigs demonstrated comparable protection induced by the TRIP/JEV.prME vaccine or heterologous JEV infection. Thus, either ADE antibodies cause no harm in the presence of neutralizing antibodies or may even have protective effects in vivo in pigs. Additionally, we found that both pre-infected and vaccinated pigs were not fully protected as low levels of viral RNA were found in lymphoid and nervous system tissue in some animals. Strikingly, the virus from the pre-infection persisted in the tonsils throughout the experiment. Finally, despite the vaccination challenge, viral RNA was detected in the oronasal swabs in all vaccinated pigs. These latter data are relevant when JEV vaccination is employed in pigs.