Motavizumab, A Neutralizing Anti-Respiratory Syncytial Virus (Rsv) Monoclonal Antibody Significantly Modifies The Local And Systemic Cytokine Responses Induced By Rsv In The Mouse Model

Motavizumab (MEDI-524) is a monoclonal antibody with enhanced neutralizing activity against RSV. In mice, motavizumab suppressed RSV replication which resulted in significant reduction of clinical parameters of disease severity. We evaluated the effect of motavizumab on the local and systemic immune response induced by RSV in the mouse model. Balb/c mice were intranasally inoculated with 106.5 PFU RSV A2 or medium. Motavizumab was given once intraperitoneally (1.25 mg/mouse) as prophylaxis, 24 h before virus inoculation. Bronchoalveolar lavage (BAL) and serum samples were obtained at days 1, 5 (acute) and 28 (long-term) post inoculation and analyzed with a multiplex assay (Beadlyte Upstate, NY) for simultaneous quantitation of 18 cytokines: IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, KC (similar to human IL-8), IL-10, IL-12p40, IL-12p70, IL-13, IL-17, TNF-α, MCP-1, RANTES, IFN-γ and GM-CSF. Overall, cytokine concentrations were lower in serum than in BAL samples. By day 28, only KC was detected in BAL specimens at low concentrations in all groups. Administration of motavizumab significantly reduced (p < 0.05) BAL concentrations of IL-1α, IL-12p70 and TNF-α on day 1, and concentrations of IFN-γ on days 1 and 5 compared with RSV-infected untreated controls. In the systemic compartment, the concentrations of IL-10, IFN-γ and KC were significantly reduced in the motavizumab-treated mice compared with the untreated controls. In summary, prophylactic administration of motavizumab was associated with significant reductions on RSV replication and concentrations of cytokine and chemokines, which are likely related to the improvement observed in clinical markers of disease severity

Constitutive expression of selected genes from the pentose phosphate and aromatic pathways increases the shikimic acid yield in high-glucose batch cultures of an Escherichia coli strain lacking PTS and pykF

BACKGROUND: During the last two decades many efforts have been directed towards obtaining efficient microbial processes for the production of shikimic acid (SA); however, feeding high amounts of substrate to increase the titer of this compound has invariably rendered low conversion yields, leaving room for improvement of the producing strains. In this work we report an alternative platform to overproduce SA in a laboratory-evolved Escherichia coli strain, based on plasmid-driven constitutive expression of six genes selected from the pentose phosphate and aromatic amino acid pathways, artificially arranged as an operon. Production strains also carried inactivated genes coding for phosphotransferase system components (ptsHIcrr), shikimate kinases I and II (aroK and aroL), pyruvate kinase I (pykF) and the lactose operon repressor (lacI). RESULTS: The strong and constitutive expression of the constructed operon permitted SA production from the beginning of the cultures, as evidenced in 1 L batch-mode fermentors starting with high concentrations of glucose and yeast extract. Inactivation of the pykF gene improved SA production under the evaluated conditions by increasing the titer, yield and productivity of this metabolite compared to the isogenic pykF(+) strain. The best producing strain accumulated up to 43 g/L of SA in 30 h and relatively low concentrations of acetate and aromatic byproducts were detected, with SA accounting for 80% of the produced aromatic compounds. These results were consistent with high expression levels of the glycolytic pathway and synthetic operon genes from the beginning of fermentations, as revealed by transcriptomic analysis. Despite the consumption of 100 g/L of glucose, the yields on glucose of SA and of total aromatic compounds were about 50% and 60% of the theoretical maximum, respectively. The obtained yields and specific production and consumption rates proved to be constant with three different substrate concentrations. CONCLUSIONS: The developed production system allowed continuous SA accumulation until glucose exhaustion and eliminated the requirement for culture inducers. The obtained SA titers and yields represent the highest reported values for a high-substrate batch process, postulating the strategy described in this report as an interesting alternative to the traditionally employed fed-batch processes for SA production

Molecular epidemiology of Plasmodium vivax in Latin America: polymorphism and evolutionary relationships of the circumsporozoite gene

BACKGROUND: The origins and dispersal of Plasmodium vivax to its current worldwide distribution remains controversial. Although progress on P. vivax genetics and genomics has been achieved worldwide, information concerning New World parasites remains fragmented and largely incomplete. More information on the genetic diversity in Latin America (LA) is needed to better explain current patterns of parasite dispersion and evolution. METHODS: Plasmodium vivax circumsporozoite protein gene polymorphism was investigated using polymerase chain reaction amplification and restriction fragment length polymorphism (PCR-RFLP), and Sanger sequencing in isolates from the Pacific Ocean coast of Mexico, Nicaragua, and Peru. In conjunction with worldwide sequences retrieved from the Genbank, mismatch distribution analysis of central repeat region (CRR), frequency estimation of unique repeat types and phylogenetic analysis of the 3′ terminal region, were performed to obtain an integrative view of the genetic relationships between regional and worldwide isolates. RESULTS: Four RFLP subtypes, vk210a, b, c and d were identified in Southern Mexico and three subtypes vk210a, e and f in Nicaragua. The nucleotide sequences showed that Mexican vk210a and all Nicaraguan isolates were similar to other American parasites. In contrast, vk210b, c and d were less frequent, had a domain ANKKAEDA in their carboxyl end and clustered with Asian isolates. All vk247 isolates from Mexico and Peru had identical RFLP pattern. Their nucleotide sequences showed two copies of GGQAAGGNAANKKAGDAGA at the carboxyl end. Differences in mismatch distribution parameters of the CRR separate vk247 from most vk210 isolates. While vk247 isolates display a homogeneous pattern with no geographical clustering, vk210 isolates display a heterogeneous geographically clustered pattern which clearly separates LA from non-American isolates, except vk210b, c and d from Southern Mexico. CONCLUSIONS: The presence of vk210a in Mexico and vk210e, f and g in Nicaragua are consistent with other previously reported LA isolates and reflect their circulation throughout the continent. The vk210b, c and d are novel genotypes in LA. Their genetic relationships and low variability within these vk210 and/or within the vk247 parasites in Southern Mexico suggest its recent introduction and/or recent expansion to this region. The global analysis of P. vivax csp suggests this parasite introduction to the region and likely LA by different independent events

América Latina. Los derechos y las prácticas ciudadanas a la luz de los movimientos populares

A partir, fundamentalmente, de los análisis de caso y los datos que ha sistematizado el Observatorio Social de América Latina (OSAL), nuestra propuesta gira en torno a dos preguntas centrales: ¿qué características presenta la noción de ciudadanía en las luchas sociales latinoamericanas recientes?, y ¿qué importancia adquiere dicha dimensión para la consecución de un propósito democrático? Buscando responder ambas, hemos dividido la exposición en tres apartados. En el primero se exploran los elementos que han favorecido el reposicionamiento de la noción de ciudadanía, dentro del horizonte y discurso de las movilizaciones que a partir del año 2000 han aparecido en distintos puntos del subcontinente. En el segundo, se examinan las características más relevantes que desde nuestro punto de vista hilvanan su diversidad. Y, finalmente, en el último se desarrollan las razones por las cuales consideramos que la noción de ciudadanía ocupa un lugar estratégico en la lucha social latinoamericana de este inicio de milenio.Presentación | 9 Lucha social y derechos ciudadanos en América Latina Margarita Favela Gavia y Diana Guillén | 21 Conflictos y tensiones en torno del Estado ampliado en América Latina: Brasil y México entre la crisis orgánica del Estado y el problema de la hegemonía Lucio Oliver | 51 Movimiento-partido: el caso del Movimiento de los Trabajadores sin Tierra (MST) en Brasil Adelita Neto Carleial | 81 Seguridad alimentaria y diseño de nuevos espacios públicos en Brasil Elza Maria Franco Braga | 111 Democracia y ciudadanía en el movimiento lopezobradorista Carlos Figueroa Ibarra y Octavio H. Moreno | 129 Venciendo el miedo: retoños de movimientos sociales en el contexto de la recuperación democrática en Perú (2000-2006) Fabiola Escárzaga | 155 Reflexiones sobre la democracia y el significado de un gobierno de los movimientos sociales en Bolivia Dunia Mokrani Chávez | 191 Entre la izquierda partidista y la izquierda social: el movimiento étnico maya y las opciones político-partidistas en Guatemala Luis Fernando Mack, Máximo Ba Tiul e Ivonne Solórzano | 215 Movimiento social y proceso político en Haití (1986-2006) Alejandro Álvarez Martínez | 24

How Plants Sense Wounds: Damaged-Self Recognition Is Based on Plant-Derived Elicitors and Induces Octadecanoid Signaling

Background: Animal-derived elicitors can be used by plants to detect herbivory but they function only in specific insect– plant interactions. How can plants generally perceive damage caused by herbivores? Damaged-self recognition occurs when plants perceive molecular signals of damage: degraded plant molecules or molecules localized outside their original compartment. Methodology/Principal Findings: Flame wounding or applying leaf extract or solutions of sucrose or ATP to slightly wounded lima bean (Phaseolus lunatus) leaves induced the secretion of extrafloral nectar, an indirect defense mechanism. Chemically related molecules that would not be released in high concentrations from damaged plant cells (glucose, fructose, salt, and sorbitol) did not elicit a detectable response, excluding osmotic shock as an alternative explanation. Treatments inducing extrafloral nectar secretion also enhanced endogenous concentrations of the defense hormone jasmonic acid (JA). Endogenous JA was also induced by mechanically damaging leaves of lima bean, Arabidopsis, maize, strawberry, sesame and tomato. In lima bean, tomato and sesame, the application of leaf extract further increased endogenous JA content, indicating that damaged-self recognition is taxonomically widely distributed. Transcriptomic patterns obtained with untargeted 454 pyrosequencing of lima bean in response to flame wounding or the application of leaf extract or JA were highly similar to each other, but differed from the response to mere mechanical damage. W

EFECTO DE LA DENSIDAD CELULAR Y LA MULTIPLICIDAD DE INFECCIÓN SOBRE LA PRODUCCIÓN DE BACULOVIRUS RECOMBINANTES EN CULTIVOS DE CÉLULAS DE INSECTO

El sistema células de insecto-baculovirus ha demostrado ser un sistema útil y versátil para la producción de proteínas recombinantes. Consiste en la infección de células de insecto con un baculovirus recombinante que contiene el gen de la proteína de interés. Una de las principales limitantes del sistema es obtener resguardos virales con alto contenido de partículas virales infecciosas (unidades formadoras de placa, ufp). En este trabajo se evaluó el efecto de la multiplicidad de infección (MDI) y la concentración celular al momento de la infección (CCI) en la amplificación de un baculovirus recombinante. Se evaluaron combinaciones de MDI de 0.1 y 1 ufp/ célula con CCI de 1 y 2 x106 cél/mL. Se siguieron las cinéticas de crecimiento de las células infectadas, la concentración de proteína total y de la proteína gp64 en el sobrenadante de los cultivos y los títulos virales al momento de la cosecha. Se encontró que una MDI de 0.1 ufp/cél y una concentración celular de 1x106 cél/mL resultaron en el mayor título viral, 3.8 ± 2 x108 ufp/mL. Los mayores títulos virales estuvieron acompañados por un menor crecimiento celular. Los resultados de este trabajo pueden ser utilizados para producir resguardos de baculovirus recombinantes con títulos virales altos y mejorar la eficiencia del proceso

Efecto de la densidad celular y la multiplicidad de infección sobre la producción de baculovirus recombinantes en cultivos de células de insecto

The insect cell-baculovirus expression system is versatile and useful for the production of recombinant proteins. It consists in infecting insect cell cultures with a recombinant baculovirus that contains the gene of interest. An important limitation of the system is the limited availability of baculoviral stocks with high titers of infectious particles (plaque forming units, pfu). In this work, the effect of multiplicity of infection (MOI) and cell concentration at the time of infection (CCI) on the yield of baculovirus infectious particles was investigated. Combinations of two values for MOI (0.1 or 1 pfu/cell) and CCI (1 or 2 x106 cel/mL) were tested. Kinetics of cell growth, total protein and gp64 concentrations in the culture supernatant, and the baculovirus titer at the time of harvest were determined. The highest viral titers, 3.8 ± 2 x108 pfu/mL, were obtained in cultures infected at a MOI = 0.1 pfu/cell and a CCI = 1x106 cell/mL. Such cultures had the lowest cell growth after infection. The results obtained in this work can be used for the efficient production of baculovirus stocks with high viral titers.El sistema células de insecto-baculovirus ha demostrado ser un sistema útil y versátil para la producción de proteínas recombinantes. Consiste en la infección de células de insecto con un baculovirus recombinante que contiene el gen de la proteína de interés. Una de las principales limitantes del sistema es obtener resguardos virales con alto contenido de partículas virales infecciosas (unidades formadoras de placa, ufp). En este trabajo se evaluó el efecto de la multiplicidad de infección (MDI) y la concentración celular al momento de la infección (CCI) en la amplificación de un baculovirus recombinante. Se evaluaron combinaciones de MDI de 0.1 y 1 ufp/célula con CCI de 1 y 2 x106 cél/mL. Se siguieron las cinéticas de crecimiento de las células infectadas, la concentración de proteína total y de la proteína gp64 en el sobrenadante de los cultivos y los títulos virales al momento de la cosecha. Se encontró que una MDI de 0.1 ufp/cél y una concentración celular de 1x106 cél/mL resultaron en el mayor título viral, 3.8 ± 2 x108 ufp/mL. Los mayores títulos virales estuvieron acompañados por un menor crecimiento celular. Los resultados de este trabajo pueden ser utilizados para producir resguardos de baculovirus recombinantes con títulos virales altos y mejorar la eficiencia del proceso