Leishmania infantum induces high phagocytic capacity and intracellular nitric oxide production by human proinflammatory monocyte

BACKGROUND The mechanism of resistance to SbIII in Leishmania is complex, multifactorial and involves not only biochemical mechanisms, but also other elements, such as the immune system of the host. OBJECTIVES In this study, putative changes in the immunological profile of human monocytes infected with wild-type (WT) and antimony (SbIII)-resistant Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum lines were evaluated. METHODS Susceptibility assays WT and SbIII-resistant L. braziliensis and L. infantum were performed using lines THP-1 human monocytic lineage. Phagocytic capacity, cytokine profile, intracellular nitric oxide (NO) production and surface carbohydrate residues profile were performed in peripheral blood monocytes by flow cytometry. FINDINGS The phagocytic capacity and intracellular NO production by classical (CD14++CD16-) and proinflammatory (CD14++CD16+) monocytes were higher in the presence of L. infantum lines compared to L. braziliensis lines. The results also highlight proinflammatory monocytes as the cellular subpopulation of major relevance in a phagocytosis event and NO expression. It is important to note that L. infantum induced a proinflammatory cytokine profile characterised by higher levels of TNF-α in culture supernatant than L. braziliensis. Conversely, both Leishmania lines induce high levels of IL-6 in culture supernatant. Analysis of the expression profile of surface carbohydrates showed that L. braziliensis presents 4.3-fold higher expression of galactose(β1,4)N-acetylglucosamine than L. infantum line. Interestingly, the expression level of α-N-acetylgalactosamine residues was 2-fold lower in the SbIII-resistant L. braziliensis line than its counterpart WT line, indicating differences in surface glycoconjugates between these lines. MAIN CONCLUSIONS Our results showed that L. braziliensis and L. infantum induce different innate immune responses and a highly inflammatory profile, which is characteristic of infection by L. infantum, the species associated with visceral disease.

Estudios de susceptibilidad de cepas de Leishmania aethiopica frente a alcaloides de Galipea longiflora (Evanta) / Susceptibility studies on Leishmania aethiopica strains against total alkaloids from Galipea longiflora (Evanta)

El Instituto de Investigaciones Fármaco Bioquímicas (IIFB), de la Facultad de Ciencias Farmacéuticas y Bioquímicas, de la UMSA, desarrolla trabajos sobre la actividad leishmanicida, de los alcaloides totales (CAT) obtenidos de la corteza de la especie medicinal amazónica conocida como Evanta (Galipea longiflora) por los Pueblos Tacana, Tsimane y Mosetene. Como parte de las actividades del Proyecto UMSA-ASDI Biomoleculas de interés medicinal e industrial (antiparasitarios) hemos podido contar con la estadía, en el IIFB, de un investigador del Armauer Hansen Research Institute (AHRI) de Etiopia, lo que nos ha permitido desarrollar evaluaciones de CAT, Miltefocine y Amfotericina B, frente a cepas de Leishmania aethiopica, agente causante de las diversa formas de Leishmaniais cutánea en Etiopía. Un total de seis cepas, de L. aethiopica, fueron adaptadas a condiciones in vitro y mostraron un comportamiento homogéneo frente a CAT, cinco de estas cepas mostraron un valor promedio de IC50 = 8,68 ±1,56 mg/mL, valor algo inferior a los calculados para nuestras cepas de referencia, L. amazonensis y L. braziliensis con IC50 = 11,73 ± 4,32 mg/mL y IC50 = 12,28 ±- 2,95 mg/mL, respectivamente. Excepto por una cepa de L. aethiopica que mostro valores consistentemente más elevados que el resto con IC50= 14,37 ± 3,58 mg/mL. Como consecuencia de esta interacción científica, la Universidad Mayor de San Andrés (UMSA) ha firmado un Memorandum de Entendimiento para el desarrollo de investigaciones conjuntas, con el Armauer Hansen Research Institute (AHRI), dependiente del Ministerio de Salud de Etiopia y explorar la posibilidad de que nuestra experiencia de validación clínica con Evanta en el tratamiento de leishmaiasis cutánea, en Bolivia, podría ser replicada en Etiopía, donde se reportan entre 20,000 a 30,000 nuevos casos de Leismaniasis por año.

The Instituto de Investigaciones Fármaco Bioquímicas (IIFB), at the Faculty of Pharmaceutical and Biochemical Sciences, from UMSA, carry out work related to the leishmanicidal activity of the total alkaloids (CAT) obtained from the bark of the Amazonian medicinal species known as Evanta (Galipea longiflora) by the Tacana, Tsimane y Mosetene people. As part of the activities develop by the UMSA-ASDI Project Biomolecules of medicinal and industrial Interest (antiparasitic) we had a visit, in our laboratories at IIFB, of a researcher from The Armauer Hansen Research Institute (AHRI) from Ethiopia, during his stay we were able to carry out evaluations of CAT, Miltefocine and Anphotericin B, against strains of L. aethiopica, causative agent of the different manifestations of cutaneous leishmaniasis in Ethiopia. A total of six strains of L. aethiopica, were adapted to in vitro a conditions, at IIFB; and did show homogenous behavior against CAT. Five of the strains, showed an average calculated value for IC50 = 8.68 ±1.56 mg/mL, a value somewhat lower to the calculated for the reference strains L. amazonensis and L. braziliensis with IC50 = 11.73 ± 4.32 mg/mL and IC50 = 12.28 +/- 2.95 mg/mL, respectively. Except for one strain that showed values somewhat higher, to the other strains, consistently through our studies, with IC50 = 14.37 ± 3.58 mg/mL. As a consequence of our scientific interaction, the Universidad Mayor de San Andrés (UMSA) has signed a Memorandum of Understanding for the development of joint research with the Armauer Hansen Research Institute (AHRI) that belongs to the Ministry of Health in Ethiopia, and explore the possibilities to replicate the Bolivian clinical validation experience of Evanta in the treatment of cutaneous leishmaniasis, in Ethiopia where the annual incidence is estimated to be between 20, 000 to 30, 0000.

Antileishmanial metabolites from Lantana balansae

ABSTRACT Eleven compounds, 12-oxo-phytodienoic acid (1), persicogenin (2), eriodictyol 3′,4′,7-trimethyl ether (3), phytol (4), spathulenol (5), 4-hydroxycinnamic acid (6), onopordin (7), 5,8,4′-trihydroxy-7,3′-dimethoxyflavone (8), quercetin (9), jaceosidin (10), and 8-hydroxyluteolin (11), were isolated from an ethanol extract of Lantana balansae Briq., Verbenaceae, that was found to possess antileishmanial activity. The structures of the compounds were determined by NMR spectroscopy and HR mass spectrometry, and 1, 2, 3, 7, 8 and 9 were investigated for antiprotozoal activity toward promastigotes of Leishmania amazonensis and Leishmania braziliensis. Compound 1 was shown to be the most potent, with the IC50 values 2.0 µM toward L. amazonensis and 0.68 µM toward L. braziliensis, although less potent than the positive control Amphotericin B. All compounds have been reported previously, but this is the first report of the isolation of a cyclopentenone fatty acid (1) and flavanones (2 and 3) from a Lantana species.

Expressão gênica associada à produção de IFNG na resposta inicial à Leishmania braziliensis / Gene expression associated to IFNG production at initial response to infection with Leishmania braziliensis

Células de voluntários saudáveis, expostas in vitro a Leishmania, podem produzir altos níveis de IFNG na primeira exposição ao parasita, caracterizando os indivíduos como alto respondedores (AR), ou baixos níveis de IFNG, caracterizando os indivíduos baixo respondedores (BR). O objetivo deste estudo foi estudar o perfil de expressão gênica associado ao padrão de produção de IFNG de indivíduos AR e BR. Também avaliamos se as assinaturas gênicas identificadas nos indivíduos AR e BR se associam com o padrão de resposta imune observado em indivíduos de área endêmica identificada como subclínicos (SC) ou portadores de Leishmaniose Cutânea Localizada (LC). Inicialmente, Células Mononucleares do Sangue Periférico (CMSP) de voluntários saudáveis foram estimuladas in vitro com Leishmania braziliensis e identificamos indivíduos AR (com produção de IFNG acima de 330 pg/ml)...

Naïve volunteers exposed to Leishmania in vitro can be high IFNG producers, characterizing a high-responder (HR), or low IFNG producers, characterizing a low-responder (LR). The purpose of this work is to characterize the gene expression profile associated to IFNG production in HR and LR individuals. Formerly, we analyzed if the gene signature identified could be associated with the pattern of immune response in individuals from endemic areas identified as subclinical (SC), or patients with Localized Cutaneous Leishmaniasis (LC). Initially, we stimulated Peripheral Blood Mononuclear Cells (PBMCs) from healthy volunteers in vitro with Leishmania braziliensis where we identified HR (IFNG production above 330 pg/ml)...

DISEÑO Y PRODUCCIÓN DE UNA HERRAMIENTA MOLECULAR PARA EL ESTUDIO DEL N-TERMINAL DE LA NICOTINAMIDA MONONUCLEÓTIDO ADENILIL TRANSFERASA (NMNAT) EN Leishmania braziliensis / DESIGN AND PRODUCTION OF A MOLECULAR TOOL TO STUDY OF N-TERMINAL NICOTINAMIDE MONONUCLEOTIDE ADENYLYL TRANSFERASE (NMNAT) IN Leishmania braziliensis / DESIGN E PRODUÇÃO DE UMA FERRAMENTA MOLECULAR PARA O ESTUDO DO TERMINALN DA NICOTINAMIDA CICLASE MONONUCLEÓTIDO TRANSFERASE (NMNAT) EM Leishmania braziliensis

Leishmania braziliensis es un parásito protozoario causante de la mayor parte de casos de leishmaniasis cutánea en al menos quince países del continente americano. La Organización Mundial de la Salud (OMS) ha reportado que cerca de doce millones de personas están infectadas en el mundo y que este número aumenta cada año. Debido al delicado problema de salud pública derivado de la prevalencia de esta enfermedad se hace necesario el estudio del metabolismo de este parásito. En tal sentido se ha estudiado la proteína NMNAT de este parásito, la cual es una enzima central del metabolismo de todos los organismos al estar encargada de la síntesis del NAD+, un importante cofactor en reacciones redox de procesos centrales del metabolismo celular. En la NMNAT de L. braziliensis se ha encontrado una secuencia de 44 aminoácidos en el extremo N-terminal carente de homología con la proteína del hospedero. En este estudio se produjeron anticuerpos IgG específicos contra esta secuencia, utilizando como antígenos péptidos que contuvieran la secuencia mencionada. Los anticuerpos obtenidos mostraron un reconocimiento de la NMNAT recombinante de L. braziliensis mediante ensayo por western blot.

Leishmania braziliensis is a protozoan which is cause of the most of the cutaneous leishmaniasis cases in at least 15 countries from America. World Health Organization (WHO) has reported that around 12 millions of people are infected in the world and this number increase every year. Because of the delicate problem of public health due to the prevalence of this disease, it is necessary the metabolism study in this parasite. In this way has been studied NMNAT protein of the parasite, which is a central enzyme of the metabolism of all organisms, since it is in charge of synthesizing NAD+, an important cofactor in oxidation-reduction reactions of central processes in the cellular metabolism. In The NMNAT of L. has been found a 43 amino acids sequence in the N terminal, which does not have homology with the protein in the human host. In this study were produced IgG antibodies against this sequence, using like antigens peptides that had the mentioned sequence. The produced antibodies recognized the recombinant NMNAT of L. braziliensis through western blot assay.

Leishmania braziliensis é um parasita protozoário que causa a maioria dos casos de leishmaniose cutânea em pelo menos 15 países das Américas. A Organização Mundial de Saúde (OMS) informou que cerca de 12 milhões de pessoas estão infectadas em todo o mundo e esse número aumenta a cada ano. Devido ao delicado problema de saúde pública decorrentes da prevalência desta doença é necessário estudar o metabolismo do parasita. A este respeito temos estudado a proteína NMNAT deste parasita, que é uma enzima central no metabolismo de todos os organismos de estar envolvido na produção de NAD+, um importante cofator em reações redox de processos centrais de celulares metabolismo. No L. braziliensis NMNAT encontrou uma seqüencia de 43 aminoácidos no terminal N homologia com a proteína faltando host. Este estudo produziu anticorpos IgG específicos para esta seqüência, usando como peptídeos de antígeno contendo a seqüência mencionada. Os anticorpos obtidos mostraram um reconhecimento da NMNAT L. braziliensis recombinantes por meio de julgamento por western blot.