Mycobacterium tuberculosis Rv0679c protein sequences involved in host-cell infection: Potential TB vaccine candidate antigen

Hasta la fecha, la función de muchas proteínas de membrana hipotéticas de Mycobacterium tuberculosis aún se desconoce y su participación en las interacciones patógeno-huésped aún no se ha definido claramente. En este estudio, se evaluó la actividad biológica de los péptidos derivados de la proteína de membrana hipotética Rv0679c de M. tuberculosis y su participación en las interacciones patógeno-huésped. La transcripción del gen Rv0679c se estudió en 26 Mycobacteriumspp. Son. Los anticuerpos generados contra los supuestos epítopos de células B de Rv0679c se usaron en ensayos de inmunotransferencia y microscopía inmunoelectrónica. Los péptidos sintéticos que abarcan toda la longitud de la proteína fueron probados por su capacidad para unirse a las células A549 y U937. Los péptidos de unión de alta actividad (HABP) identificados en Rv0679c se probaron para determinar su capacidad para inhibir la invasión de micobacterias en las células.To date, the function of many hypothetical membrane proteins of Mycobacterium tuberculosis is still unknown and their involvement in pathogen-host interactions has not been yet clearly defined. In this study, the biological activity of peptides derived from the hypothetical membrane protein Rv0679c of M. tuberculosis and their involvement in pathogen-host interactions was assessed. Transcription of the Rv0679c gene was studied in 26 Mycobacterium spp. Strains. Antibodies raised against putative B-cell epitopes of Rv0679c were used in Western blot and immunoelectron microscopy assays. Synthetic peptides spanning the entire length of the protein were tested for their ability to bind to A549 and U937 cells. High-activity binding peptides (HABPs) identified in Rv0679c were tested for their ability to inhibit mycobacterial invasion into cells

A large size chimeric highly immunogenic peptide presents multistage plasmodium antigens as a vaccine candidate system against malaria

Rational strategies for obtaining malaria vaccine candidates should include not only a proper selection of target antigens for antibody stimulation, but also a versatile molecular design based on ordering the right pieces from the complex pathogen molecular puzzle towards more active and functional immunogens. Classical Plasmodium falciparum antigens regarded as vaccine candidates have been selected as model targets in this study. Among all possibilities we have chosen epitopes of PfCSP, STARP; MSA1 and Pf155/RESA from pre- A nd erythrocyte stages respectively for designing a large 82-residue chimeric immunogen. A number of options aimed at diminishing steric hindrance for synthetic procedures were assessed based on standard Fmoc chemistry such as building block orthogonal ligation; pseudo-proline and microwave-assisted procedures, therefore the large-chimeric target was produced, characterized and immunologically tested. Antigenicity and functional in vivo efficacy tests of the large-chimera formulations administered alone or as antigen mixtures have proven the stimulation of high antibody titers, showing strong correlation with protection and parasite clearance of vaccinated BALB/c mice after being lethally challenged with both P. berghei-ANKA and P. yoelii 17XL malaria strains. Besides, 3D structure features shown by the large-chimera encouraged as to propose using these rational designed large synthetic molecules as reliable vaccine candidate-presenting systems

La imagen y la narrativa como herramientas para el abordaje psicosocial en escenarios de violencia. Municipios de Chaparral e Ibagué

La imagen y la narrativa como herramientas para el abordaje psicosocial en escenarios de violencia. Municipios de Chaparral e Ibagué.El presente trabajo contiene información correspondiente del diplomado de profundización acompañamiento psicosocial en escenarios de violencia. En primera instancia se observa el análisis del relato “1 Estefanía Gutiérrez”; teniendo en cuenta el abordaje psicosocial, en el cual se abarcan temas como la restauración de la identidad y la autonomía, que le brindan a la víctima la oportunidad de aumentar las cualidades como agente de cambio tanto en el ámbito individual como en el colectivo; también se busca reconocer a las personas como seres subjetivos para lograr proyectar un oportuno acompañamiento, se implementaron nueve preguntas referente al relato elegido, tres Estratégicas que inducen a dar una respuesta, tres circulares que permiten comprender la conexión con el entorno y tres reflexivas que ayudan al individuo a reflexionar sobre las fortalezas que tiene para reconstruir su proyecto de vida. En segundo lugar se observara el análisis del caso de las comunidades de Cacarica en donde se establece una serie de estrategias de acompañamiento psicosocial, para ello se parte desde la argumentación de determinados ítems, con base a las lecturas sugeridas de la unidad 4, 5 y 9; en la cual se reconocen diversas acciones de apoyo para la realizar una intervención, tales como la terapia de crisis e Intervención Debriefing, así mismo como las estrategias psicosociales que se pueden implementar entre ellas la foto voz, las coaliciones comunitarias y la terapia narrativa. Finalmente se anexa el informe analítico y reflexivo, como producto de la experiencia obtenida a partir de la herramienta de foto voz, en el cual, se experimentó el uso de esta herramienta vinculada a las estructuras simbólicas, la imagen como acción política, los recursos de afrontamiento, la memoria y subjetividad. Palabras Claves: Enfoques Narrativos, Intervención, Estrategias, VíctimasThe present work contains corresponding information of the diploma of deepening psychosocial accompaniment in scenarios of violence. In the first instance the analysis of the story "1 Estefania Gutiérrez" is observed; taking into account the psychosocial approach, which includes topics such as the restoration of identity and autonomy, which give the victim the opportunity to increase the qualities as an agent of change both individually and collectively; also seeks to recognize people as subjective beings to achieve a timely accompaniment, were implemented nine questions concerning the chosen story, three Strategies that lead to give an answer, three circular that allow to understand the connection with the environment and three reflective that help the individual to reflect on the strengths he has to rebuild his life project. Secondly, the analysis of the case of the communities of Cacarica, where a series of psychosocial accompaniment strategies is established, is based on the argumentation of certain items, based on the suggested readings of unit 4, 5 and 9; in which various actions of support for intervention are recognized, such as crisis therapy and Intervention Debriefing, as well as the psychosocial strategies that can be implemented, among them, photo voice, community coalitions and narrative therapy. Finally, the analytical and reflective report is annexed, as a product of the experience gained from the photo voice tool, in which the use of this tool linked to symbolic structures, image as political action, resources of coping, memory and subjectivity. Keywords: Narrative Approaches, Intervention, Strategies, Victim

Mycobacterium tuberculosis Rv0679c protein sequences involved in host-cell infection: Potential TB vaccine candidate antigen

BACKGROUND: To date, the function of many hypothetical membrane proteins of Mycobacterium tuberculosis is still unknown and their involvement in pathogen-host interactions has not been yet clearly defined. In this study, the biological activity of peptides derived from the hypothetical membrane protein Rv0679c of M. tuberculosis and their involvement in pathogen-host interactions was assessed. Transcription of the Rv0679c gene was studied in 26 Mycobacterium spp. Strains. Antibodies raised against putative B-cell epitopes of Rv0679c were used in Western blot and immunoelectron microscopy assays. Synthetic peptides spanning the entire length of the protein were tested for their ability to bind to A549 and U937 cells. High-activity binding peptides (HABPs) identified in Rv0679c were tested for their ability to inhibit mycobacterial invasion into cells. RESULTS: The gene encoding Rv0679c was detected in all strains of the M. tuberculosis complex (MTC), but was only transcribed in M. tuberculosis H37Rv, M. tuberculosis H37Ra and M. africanum. Anti-Rv0679c antibodies specifically recognized the protein in M. tuberculosis H37Rv sonicate and showed its localization on mycobacterial surface. Four HABPs inhibited invasion of M. tuberculosis to target cells by up to 75%. CONCLUSIONS: The results indicate that Rv0679c HABPs and in particular HABP 30979 could be playing an important role during M. tuberculosis invasion of host cells, and therefore could be interesting research targets for studies aimed at developing strategies to control tuberculosis

Índice de calidad ecológica con base en macroinvertebrados acuáticos para la cuenca del río Negro (ICE RN-MAE), Colombia

Los índices disponibles para la evaluación del estado ecológico de los ríos en Colombia están basados principalmente en hipótesis subjetivas generalizadas acerca de la toleración de los macroinvertebrados, un proceso que presenta limitaciones. En este estudio se presenta la aplicación de un método para establecer un índice de calidad ecológica para sistemas lóticos, basado en abundancia de macroinvertebrados y variables fisicoquímicas. Se tomó como caso de estudio la cuenca del rio Negro (Colombia). Este nuevo índice se ha formulado como alternativa al BMWP-Col y consiste en la determinación de un gradiente ambiental a partir de un Análisis de Correspondencia Canónica de correlaciones entre abundancias y registros fisicoquímicos. Los puntajes de las estaciones -obtenidos en las correlaciones- son estandarizados y usados en un modelo de Promedios Ponderados (WA); en el modelo se ponderan también las abundancias para estimar los valores óptimos y de tolerancia de cada taxón. Con ellos y la abundancia se calcula los valores del Índice de Calidad Ecológica con base en macroinvertebrados acuáticos para la cuenca del rio Negro (ICE RN-MAE). Se utilizan los valores del índice junto con las concentraciones de fósforo total (FT) en un análisis de agrupamiento, para así clasificar los sitios de estudio. De ahí se obtienen finalmente los valores medios, máximos, mínimos y de desviación estándar del ICE RN-MAE y FT. Con ellos se definen los umbrales que corresponden a diferentes categorías de calidad ecológica (buena, regular y crítica)

Identification of peptides with high red blood cell and hepatocyte binding activity in the Plasmodium falciparum multi-stage invasion proteins: PfSPATR and MCP-1

Plasmodium falciparum multi-stage proteins are involved in vital processes for parasite survival, which turns them into attractive targets for studies aimed at developing a fully effective antimalarial vaccine. MCP-1 and PfSPATR are both found in sporozoite and merozoite forms, and have been associated respectively with invasion of hepatocytes and red blood cells (RBCs). Binding assays with synthetic peptides derived from these two important proteins have enabled identifying those sequences binding with high specific activity (named High activity binding peptides-HABPs) to hepatoma-derived HepG2 cells and human RBCs. Twelve RBC HABPs were identified within the MCP-1 amino acid sequence, most of them in the C-terminal region. The MCP-1 HABPs 33387 and 33397 also presented high activity binding to HepG2 cells. PfSPATR presented four RBC HABPs and two HepG2 HABPs, but only one (32686) could bind to both cell types. RBC binding assays evidenced that binding of all HABPs was saturable and differentially affected by the enzymatic treatment of target cells. Moreover, all HABPs inhibited in vitro invasion of merozoites at 200 ?M and had particular structural features when analyzed by circular dichroism. The results suggest that these synthetic peptides capable of binding to the two P. falciparum target cells could be potentially included in the design of a multi-stage, subunit-based, chemically synthesized antimalarial vaccine. © 2008 Elsevier Masson SAS. All rights reserved

Identification of peptides with high red blood cell and hepatocyte binding activity in the Plasmodium falciparum multi-stage invasion proteins: PfSPATR and MCP-1

Plasmodium falciparum multi-stage proteins are involved in vital processes for parasite survival, which turns them into attractive targets for studies aimed at developing a fully effective antimalarial vaccine. MCP-1 and PfSPATR are both found in sporozoite and merozoite forms, and have been associated respectively with invasion of hepatocytes and red blood cells (RBCs). Binding assays with synthetic peptides derived from these two important proteins have enabled identifying those sequences binding with high specific activity (named High activity binding peptides-HABPs) to hepatoma-derived HepG2 cells and human RBCs. Twelve RBC HABPs were identified within the MCP-1 amino acid sequence, most of them in the C-terminal region. The MCP-1 HABPs 33387 and 33397 also presented high activity binding to HepG2 cells. PfSPATR presented four RBC HABPs and two HepG2 HABPs, but only one (32686) could bind to both cell types. RBC binding assays evidenced that binding of all HABPs was saturable and differentially affected by the enzymatic treatment of target cells. Moreover, all HABPs inhibited in vitro invasion of merozoites at 200 ?M and had particular structural features when analyzed by circular dichroism. The results suggest that these synthetic peptides capable of binding to the two P. falciparum target cells could be potentially included in the design of a multi-stage, subunit-based, chemically synthesized antimalarial vaccine. © 2008 Elsevier Masson SAS. All rights reserved

Characterization of Plasmodium falciparum integral membrane protein Pf25-IMP and identification of its red blood cell binding sequences inhibiting merozoite invasion in vitro

The identification of proteins present on the surface of Plasmodium falciparum-infected red blood cells as well as of free merozoites has been widely considered as one of the main areas of research in the development of an antimalarial vaccine due to their involvement in the parasite's pathogenesis and invasion mechanisms. Major advances had been accomplished in this area thanks to the analysis of the reported genomic sequence of P. falciparum, allowing for the identification of genes encoding for putative integral membrane proteins. This study reports for the first time the transcription of the MAL8P1.3 gene, which codifies for a 25-kDa integral membrane protein of P. falciparum (FCB-2 strain), namely, Pf25-IMP. Western blot and immunofluorescence assays using goat polyclonal sera indicate that this protein is expressed in erythrocytic asexual blood stages. A highly robust, sensible, and specific receptor-ligand interaction assay allowed identification of two high activity binding peptides (HABPs) derived from Pf25-IMP: 30577 (41YKTANENVKLASSLSDRLSR 60) and 30583 (161LNKKTVVRKIAEGLGYTIVF180). Both HABPs bound with high affinity to human red blood cells (RBCs), and such binding was susceptible to enzyme treatment with trypsin. A common RBC surface receptor of apparently 48 kDa was found for both HABPs, plus an additional 31-kDa receptor for HABP 30577. HABP 30577 inhibited merozoite invasion in vitro by 73%, while HABP 30583 showed a 59% inhibition at 200 ?M concentration. The data suggest a possible role of Pf25-IMP in merozoite invasion to RBCs and support its inclusion in further immunological studies for evaluating its potential as vaccine candidates. Published by Cold Spring Harbor Laboratory Press. Copyright © 2008 The Protein Society

Estudios de péptidos de la proteína del antígeno de membrana asociado a rhoptry (RAMA) de Plasmodium falciparum que se unen específicamente a los glóbulos rojos humanos

Plasmodium falciparum rhoptry-associated membrane antigen (RAMA) peptides used in normal red blood cell (RBC) binding assays revealed that peptides 33426 (79NINILSSVHRKGRILYDSF97) and 33460 (777HKKREKSISPHSYQKVSTKVQ797) bound with high activity, presenting nanomolar affinity constants. Such high binding activity peptides (HABPs) displayed helicoid and random coil structures as determined by circular dichroism. HABPs inhibited P. falciparum in vitro invasion of normal RBC by up to 61% (depending on concentration), suggesting that some RAMA protein regions could be involved in P. falciparum invasion of RBC. The nature and localisation of receptors on RBC surface responsible for HABP binding were studied using enzyme-treated erythrocytes and structural analysis

Mycobacterium tuberculosis Rv0679c protein sequences involved in host-cell infection: Potential TB vaccine candidate antigen

Hasta la fecha, la función de muchas proteínas de membrana hipotéticas de Mycobacterium tuberculosis aún se desconoce y su participación en las interacciones patógeno-huésped aún no se ha definido claramente. En este estudio, se evaluó la actividad biológica de los péptidos derivados de la proteína de membrana hipotética Rv0679c de M. tuberculosis y su participación en las interacciones patógeno-huésped. La transcripción del gen Rv0679c se estudió en 26 Mycobacteriumspp. Son. Los anticuerpos generados contra los supuestos epítopos de células B de Rv0679c se usaron en ensayos de inmunotransferencia y microscopía inmunoelectrónica. Los péptidos sintéticos que abarcan toda la longitud de la proteína fueron probados por su capacidad para unirse a las células A549 y U937. Los péptidos de unión de alta actividad (HABP) identificados en Rv0679c se probaron para determinar su capacidad para inhibir la invasión de micobacterias en las células.To date, the function of many hypothetical membrane proteins of Mycobacterium tuberculosis is still unknown and their involvement in pathogen-host interactions has not been yet clearly defined. In this study, the biological activity of peptides derived from the hypothetical membrane protein Rv0679c of M. tuberculosis and their involvement in pathogen-host interactions was assessed. Transcription of the Rv0679c gene was studied in 26 Mycobacterium spp. Strains. Antibodies raised against putative B-cell epitopes of Rv0679c were used in Western blot and immunoelectron microscopy assays. Synthetic peptides spanning the entire length of the protein were tested for their ability to bind to A549 and U937 cells. High-activity binding peptides (HABPs) identified in Rv0679c were tested for their ability to inhibit mycobacterial invasion into cells