P. falciparum and P. vivax Orthologous Coiled-Coil Candidates for a Potential Cross-Protective Vaccine.

Over the last four decades, significant efforts have been invested to develop vaccines against malaria. Although most efforts are focused on the development of P. falciparum vaccines, the current availability of the parasite genomes, bioinformatics tools, and high throughput systems for both recombinant and synthetic antigen production have helped to accelerate vaccine development against the P. vivax parasite. We have previously in silico identified several P. falciparum and P. vivax proteins containing α-helical coiled-coil motifs that represent novel putative antigens for vaccine development since they are highly immunogenic and have been associated with protection in many in vitro functional assays. Here, we selected five pairs of P. falciparum and P. vivax orthologous peptides to assess their sero-reactivity using plasma samples collected in P. falciparum- endemic African countries. Pf-Pv cross-reactivity was also investigated. The pairs Pf27/Pv27, Pf43/Pv43, and Pf45/Pv45 resulted to be the most promising candidates for a cross-protective vaccine because they showed a high degree of recognition in direct and competition ELISA assays and cross-reactivity with their respective ortholog. The recognition of P. vivax peptides by plasma of P. falciparum infected individuals indicates the existence of a high degree of cross-reactivity between these two Plasmodium species. The design of longer polypeptides combining these epitopes will allow the assessment of their immunogenicity and protective efficacy in animal models.

Malaria in gold-mining areas in Colombia.

Gold-mining may play an important role in the maintenance of malaria worldwide. Gold-mining, mostly illegal, has significantly expanded in Colombia during the last decade in areas with limited health care and disease prevention. We report a descriptive study that was carried out to determine the malaria prevalence in gold-mining areas of Colombia, using data from the public health surveillance system (National Health Institute) during the period 2010-2013. Gold-mining was more prevalent in the departments of Antioquia, Córdoba, Bolívar, Chocó, Nariño, Cauca, and Valle, which contributed 89.3% (270,753 cases) of the national malaria incidence from 2010-2013 and 31.6% of malaria cases were from mining areas. Mining regions, such as El Bagre, Zaragoza, and Segovia, in Antioquia, Puerto Libertador and Montelíbano, in Córdoba, and Buenaventura, in Valle del Cauca, were the most endemic areas. The annual parasite index (API) correlated with gold production (R2 0.82, p < 0.0001); for every 100 kg of gold produced, the API increased by 0.54 cases per 1,000 inhabitants. Lack of malaria control activities, together with high migration and proliferation of mosquito breeding sites, contribute to malaria in gold-mining regions. Specific control activities must be introduced to control this significant source of malaria in Colombia.

Malaria in gold-mining areas in Colombia

Gold-mining may play an important role in the maintenance of malaria worldwide. Gold-mining, mostly illegal, has significantly expanded in Colombia during the last decade in areas with limited health care and disease prevention. We report a descriptive study that was carried out to determine the malaria prevalence in gold-mining areas of Colombia, using data from the public health surveillance system (National Health Institute) during the period 2010-2013. Gold-mining was more prevalent in the departments of Antioquia, Córdoba, Bolívar, Chocó, Nariño, Cauca, and Valle, which contributed 89.3% (270,753 cases) of the national malaria incidence from 2010-2013 and 31.6% of malaria cases were from mining areas. Mining regions, such as El Bagre, Zaragoza, and Segovia, in Antioquia, Puerto Libertador and Montelíbano, in Córdoba, and Buenaventura, in Valle del Cauca, were the most endemic areas. The annual parasite index (API) correlated with gold production (R2 0.82, p < 0.0001); for every 100 kg of gold produced, the API increased by 0.54 cases per 1,000 inhabitants. Lack of malaria control activities, together with high migration and proliferation of mosquito breeding sites, contribute to malaria in gold-mining regions. Specific control activities must be introduced to control this significant source of malaria in Colombia.

Caracterización de la transmisión de Plasmodium malariae en cuatro regiones colombianas endémicas de malaria / Characterization of Plasmodium malariae transmission in four malaria endemic regions in Colombia

En Colombia, la detección del número de casos de infección por Plasmodium malariae muestra una distribución porcentual focalizada en la Costa Pacífica, donde alcanza un 95 por ciento, en contraste con el 5 por ciento de casos más esporádicos que se presentan en otras regiones. El departamento del Valle del Cauca aporta el 85 por ciento y el 15 por ciento restante corresponde a los departamentos de Chocó y Cauca. La región de Zacarías aporta el 70 por ciento, seguida por las regiones de Citronela, Puerto Merizalde, Anchicayá, Meseta y Boca Dagua, regiones que conjuntamente contribuyen con el 30 por ciento. En un estudio transversal, realizado en 1997 mediante gota gruesa en la población de Zacarías, se encontró una frecuencia de 9,1 por ciento de casos de P. malariae. Se usaron muestras de donantes infectados con gametocitos de P. malariae para alimentar mosquitos Anopheles albimanus y reproducir exitosamente el ciclo ex vivo. Se analizaron 242 plasmas obtenidos de individuos de Zacarías y Punta Soldado (Valle) y Pizarro (Chocó) para determinar la presencia de anticuerpos específicos para P. malariae. Se encontró que el 9,1 por ciento contenía anticuerpos identificables por la técnica de Elisa contra una preparación cruda de antígeno y que el 42,1 por ciento presentaba anticuerpos contra el péptido sintético (NAAG) derivado de la proteína circumesporozoíto (CS). En 50 muestras analizadas de la región del Bajo Guaviare, se encontró presencia de anticuerpos contra (NAAG) en el 16 por ciento. Los resultados de este estudio muestran una gran delimitación de los casos de la Costa Pacífica, el área de Zacarías, indicando también la posible presencia de este parásito en otras regiones del país

Los linfocitos T CD8+ en la respuesta inmune celular: ¿como funcionan?, ¿como se evaluan? / Lyphocytes T CC8+ in immune cell reaction

Los conocimientos generados en el campo de la función y la actividad de los linfocitos T CD8+, al igual que en la caracterización de las moléculas del Complejo Mayor de Histocompatibilidad han sido parte fundamental para determinar los mecanismos inmune celulares que actúan en el control de procesos infecciosos y tumorales. Los linfocitos T CD8+, tienen la capacidad de reconocer antígenos presentados por las moléculas de clase I en la superficie de las células. Una vez el antígeno es reconocido por los linfocitos, se inicia una serie de vías de activación en el linfocito que llevan finalmente a la eliminación de la célula blanco, mediante mecanismos como citotoxicidad directa o la inducción de muerte celular programada. En este artículo se revisan los principales aspectos de la respuesta celular mediada por los linfocitos T CD8+ que permiten su identificación utilizando técnicas de laboratorio como la prueba de liberación de cromio y la determinación de citocinas por ELISPOT