Virus Del Chikungunya: Características Virales Y Evolución Genética

El virus Chikungunya pertenece al género Alphavirus de la familia de los Togaviridae. Es transmitido por artrópodos, en particular por la picada de especies de mosquitos tales como Aedes aegypti y Aedes albopictus. El curso clínico característico de la infección incluye fiebres, artralgias y exantema. Desde que fue reportado en 1952 en los límites de Tanzania y Mozambique, ha generado brotes de enorme significado epidemiológico. Recientemente, fue causado un brote en las Américas por una cepa del virus, aparentemente, asiática. En la presente revisión presentamos su filogenia, estructura y organización del genoma. Enfatizaremos en el mecanismo de multiplicación y la expresión genética. Finalmente, la interacción virus-huésped y sus mecanismos de adaptación a vectores específicos también son discutido

Alergenos: relación entre función biológica y alergenicidad

Allergens can be found from many diverse sources but they have the particular quality of being able to induce immunoglobulin E (IgE) production and to provoke allergy. A common biological molecular characteristic which can explain their allergenic capacity is not known amongst the allergens. In the last few years allergens' different biological functions have been demonstrated or inferred, generating a new hypothesis about the role of the said functions in allergenic activity. To identify which biological functions have been demonstrated or inferred in the allergens and to analyse their possible influence on allergenic role, approximately two hundred allergens were revised using those already classified by the WHO's Allergen Nomenclature committee as the basis for characterisation, as were others less characterised, but having some known physicochemical properties. The allergens were grouped according to biological activity and were tabulated with their source of origin, molecular weight (MW), isoelectric point (Ip), reactivity frequency in the allergic population, potential glycosilation and disulphur formation of enlacing sites. Eighty-eight allergens were identified amongst those in which some biological activity had been reported. The grouping of these according to activity produced the following results: enzymatic (47,2%), enzyme inhibition (11,3%), transport (18,1%), cellular activity regulation (15,9%) and other activities such as conferring resistance to disease on plants and cytolysis (7,9%). In many of these allergens, biological activity has been inferred by their structural homology with known function proteins but the experiments which corroborate the said function have not been carried out. The majority of these allergens have a MWLos alergenos se encuentran en muy diversas fuentes, pero, tienen la particularidad de inducir la producción de inmunoglobulina E (IgE) y provocar alergia. No se conoce una característica molecular biológica común entre los alergenos que explique su capacidad alergénica. En los últimos años, se han demostrado o inferido diferentes funciones biológicas en los alergenos, generando nuevas hipótesis sobre el papel de dichas funciones en la actividad alergénica. Con el fin de identificar qué funciones biológicas se han demostrado o inferido en los alergenos y analizar su posible influencia en el papel alergénico, se revisaron aproximadamente doscientos alergenos teniendo como base los ya caracterizados por el Comité de Nomenclatura de Alergenos de la OMS, como también otros menos caracterizados pero con algunas propiedades fisicoquímicas conocidas. Los alergenos se agruparon de acuerdo con la actividad biológica y se tabularon con su fuente de origen, peso molecular (PM), punto isoeléctrico (pl), frecuencia de reactividad en la población alérgica, potenciales sitios de glicosilación y formación de enlaces disulfuro. Se identificaron 88 alergenos en los que se ha informado alguna actividad biológica. El agrupamiento de estos según la actividad produjo los siguientes resultados: enzimática (47,2%), inhibición de enzimas (11,3%), transporte (18,1%), regulación de la actividad celular (15,9%) y otras actividades como la de conferir resistencia a enfermedades en plantas y citólisis (7,9%). En muchos de estos alergenos, la actividad biológica ha sido inferida por su homología estructural con proteínas de función conocida, pero los experimentos que corroboren dicha función no se han realizado. La mayoría de estos alergenos tienen en común P

A new pipeline for structural characterization and classification of RNA-Seq microbiome data

Background High-throughput sequencing enables the analysis of the composition of numerous biological systems, such as microbial communities. The identification of dependencies within these systems requires the analysis and assimilation of the underlying interaction patterns between all the variables that make up that system. However, this task poses a challenge when considering the compositional nature of the data coming from DNA-sequencing experiments because traditional interaction metrics (e.g., correlation) produce unreliable results when analyzing relative fractions instead of absolute abundances. The compositionality-associated challenges extend to the classification task, as it usually involves the characterization of the interactions between the principal descriptive variables of the datasets. The classification of new samples/patients into binary categories corresponding to dissimilar biological settings or phenotypes (e.g., control and cases) could help researchers in the development of treatments/drugs. Results Here, we develop and exemplify a new approach, applicable to compositional data, for the classification of new samples into two groups with different biological settings. We propose a new metric to characterize and quantify the overall correlation structure deviation between these groups and a technique for dimensionality reduction to facilitate graphical representation. We conduct simulation experiments with synthetic data to assess the proposed method’s classification accuracy. Moreover, we illustrate the performance of the proposed approach using Operational Taxonomic Unit (OTU) count tables obtained through 16S rRNA gene sequencing data from two microbiota experiments. Also, compare our method’s performance with that of two state-of-the-art methods. Conclusions Simulation experiments show that our method achieves a classification accuracy equal to or greater than 98% when using synthetic data. Finally, our method outperforms the other classification methods with real datasets from gene sequencing experiments

Attenuation of dengue virus infection by adeno-associated virus-mediated siRNA delivery

BACKGROUND: The need for safe and effective treatment of dengue virus (DEN), a class A agent that causes dengue hemorrhagic fever/dengue shock syndrome, has been a critical global priority. An effective vaccine for DEN is not yet available. In this study the possibility of attenuating DEN infection using adeno-associated virus (AAV)-encoded short interfering RNAs (siRNA) was examined in Vero cells and human dendritic cells (DCs). METHODS: A cassette encoding siRNA targeted to a 3' untranslated sequence common to all DEN serotypes was designed and tested for its ability to attenuate DEN infection by use of AAV delivery. RESULTS: Vero cells or DCs infected with AAV-siRNA showed a significant, dose-dependent reduction in DEN infection. Treatment of DCs with AAV-siRNA also decreased the DEN-induced apoptosis of DCs and did not induce significant inflammation. CONCLUSION: These results demonstrate that AAV-mediated siRNA delivery is capable of reducing DEN infection in cells and may be useful in decreasing DEN replication in humans

Exploring the secrets of virus entry: the first respiratory syncytial virus carrying beta lactamase

BackgroundRespiratory Syncytial Virus (RSV) presents a significant health threat, especially to young children. In-depth understanding of RSV entry mechanisms is essential for effective antiviral development. This study introduces an innovative RSV variant, featuring the fusion of the beta-lactamase (BlaM) enzyme with the RSV-P phosphoprotein, providing a versatile tool for dissecting viral entry dynamics.MethodsUsing the AlphaFold2 algorithm, we modeled the tertiary structure of the P-BlaM chimera, revealing structural similarities with both RSV-P and BlaM. Functional assessments, utilizing flow cytometry, quantified beta-lactamase activity and GFP expression in infected bronchial epithelial cells. Western blot analysis confirmed the integrity of P-BlaM within virions.ResultsThe modeled P-BlaM chimera exhibited structural parallels with RSV-P and BlaM. Functional assays demonstrated robust beta-lactamase activity in recombinant virions, confirming successful P-BlaM incorporation as a structural protein. Quercetin, known for its antiviral properties, impeded viral entry by affecting virion fusion. Additionally, Ulixertinib, an ERK-1/2 inhibitor, significantly curtailed viral entry, implicating ERK-1/2 pathway signaling.ConclusionsOur engineered RSV-P-BlaM chimera emerges as a valuable tool, illuminating RSV entry mechanisms. Structural and functional analyses unveil potential therapeutic targets. Quercetin and Ulixertinib, identified as distinct stage inhibitors, show promise for targeted antiviral strategies. Time-of-addition assays pinpoint quercetin’s specific interference stage, advancing our comprehension of RSV entry and guiding future antiviral developments

Respiratory Syncytial Virus NS1 Protein Colocalizes with Mitochondrial Antiviral Signaling Protein MAVS following Infection

Respiratory syncytial virus (RSV) nonstructural protein 1(NS1) attenuates type-I interferon (IFN) production during RSV infection; however the precise role of RSV NS1 protein in orchestrating the early host-virus interaction during infection is poorly understood. Since NS1 constitutes the first RSV gene transcribed and the production of IFN depends upon RLR (RIG-I-like receptor) signaling, we reasoned that NS1 may interfere with this signaling. Herein, we report that NS1 is localized to mitochondria and binds to mitochondrial antiviral signaling protein (MAVS). Live-cell imaging of rgRSV-infected A549 human epithelial cells showed that RSV replication and transcription occurs in proximity to mitochondria. NS1 localization to mitochondria was directly visualized by confocal microscopy using a cell-permeable chemical probe for His6-NS1. Further, NS1 colocalization with MAVS in A549 cells infected with RSV was shown by confocal laser microscopy and immuno-electron microscopy. NS1 protein is present in the mitochondrial fraction and co-immunoprecipitates with MAVS in total cell lysatesof A549 cells transfected with the plasmid pNS1-Flag. By immunoprecipitation with anti-RIG-I antibody, RSV NS1 was shown to associate with MAVS at an early stage of RSV infection, and to disrupt MAVS interaction with RIG-I (retinoic acid inducible gene) and the downstream IFN antiviral and inflammatory response. Together, these results demonstrate that NS1 binds to MAVS and that this binding inhibits the MAVS-RIG-I interaction required for IFN production

Addendum for: A Study of Image Analysis Algorithms for Segmentation, Feature Extraction and Classification of Cells

Acknowledgement section is added to original article by this addendum

Virus Del Chikungunya: Características Virales Y Evolución Genética

El virus Chikungunya pertenece al género Alphavirus de la familia de los Togaviridae. Es transmitido por artrópodos, en particular por la picada de especies de mosquitos tales como Aedes aegypti y Aedes albopictus. El curso clínico característico de la infección incluye fiebres, artralgias y exantema. Desde que fue reportado en 1952 en los límites de Tanzania y Mozambique, ha generado brotes de enorme significado epidemiológico. Recientemente, fue causado un brote en las Américas por una cepa del virus, aparentemente, asiática. En la presente revisión presentamos su filogenia, estructura y organización del genoma. Enfatizaremos en el mecanismo de multiplicación y la expresión genética. Finalmente, la interacción virus-huésped y sus mecanismos de adaptación a vectores específicos también son discutido

Study of Image Analysis Algorithms for Segmentation, Feature Extraction and Classification of Cells

Recent advances in microcopy and improvements in image processing algorithms have allowed the development of computer-assisted analytical approaches in cell identification. Several applications could be mentioned in this field: Cellular phenotype identification, disease detection and treatment, identifying virus entry in cells and virus classification; these applications could help to complement the opinion of medical experts. Although many surveys have been presented in medical image analysis, they focus mainly in tissues and organs and none of the surveys about image cells consider an analysis following the stages in the typical image processing: Segmentation, feature extraction and classification. The goal of this study is to provide comprehensive and critical analyses about the trends in each stage of cell image processing. In this paper, we present a literature survey about cell identification using different image processing techniques