Cd40–Cd40 Ligand Interactions in Vivo Regulate Migration of Antigen-Bearing Dendritic Cells from the Skin to Draining Lymph Nodes

Whereas CD40–CD40 ligand interactions are important for various dendritic cell (DC) functions in vitro, their in vivo relevance is unknown. We analyzed the DC status of CD40 ligand −/− mice using a contact hypersensitivity (CHS) model system that enables multiple functions of DCs to be assessed in vivo. Immunohistochemistry of skin sections revealed no differences in terms of numbers and morphology of dendritic epidermal Langerhans cells (LCs) in unsensitized CD40 ligand −/− mice as compared with wild-type C57BL/6 mice. However, after contact sensitization of CD40 ligand −/− mice, LCs failed to migrate out of the skin and substantially fewer DCs accumulated in draining lymph nodes (DLNs). Furthermore, very few antigen-bearing DCs could be detected in the paracortical region of lymph nodes draining sensitized skin. This defect in DC migration after hapten sensitization was associated with defective CHS responses and decreased cutaneous tumor necrosis factor (TNF)-α production and was corrected by injecting recombinant TNF-α or an agonistic anti-CD40 monoclonal antibody. Thus, CD40–CD40 ligand interactions in vivo regulate the migration of antigen-bearing DCs from the skin to DLNs via TNF-α production and play a vital role in the initiation of acquired T cell–mediated immunity

In Vitro Murine Lymphoma L5178y-R Cells Growth Inhibition By Endophytic Fungi Isolated From Lophocereus Marginatus

Background: Chemotherapy is one of the main treatments to fight cancer. However, about 90% of failures in this procedure are due to the invasion and metastasis of drug-resistant cancer cells. Therefore, the search for new drugs has become critical in oncology. Endophytic fungi, as important sources of bioactive compounds, represent an alternative for the isolation, characterization, and development of new pharmacological treatments for cancer control. The aim of the present study was to evaluate the cytotoxic activity of liquid culture extracts of endophytic fungi isolated from Lophocereus marginatus against murine lymphoma L5178Y-R cells. Methods: Endophytic fungi obtained from L. marginatus stems were isolated and morphologically characterized. Aqueous, methanolic, and ethyl acetate extracts were obtained from fungal liquid cultures. To evaluate the anticancer activity, we used tumor L5178Y-R cells and control peripheral blood mononuclear cells (PBMCs). Extracts were evaluated at 250 and 25 µg/mL and 250 µg/mL, using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide) colorimetric reduction assay to determine cytotoxicity. Vincristine and 1% DMSO were used as positive and negative controls, respectively. The IC50 value and selectivity index (SI) were determined only for the extracts that presented the highest antitumor activity. These isolates were molecularly identified from sequencing of the spacer region of the ribosomal DNA internal transcript (ITS). A metabolite production curve was performed with selected isolates to determine the time of the highest antitumor activity. Results: Ten endophytic fungi from L. marginatus were isolated and morphologically characterized. Results showed that aqueous extracts presented lower lymphoma cells growth inhibition (\u3c 50%) at the highest concentration evaluated (250 µg/mL), as compared with ethyl acetate and methanolic extracts, which showed up to 93.4% and 94.3% cells growth inhibition, respectively. Ten extracts with \u3e 80% tumor cells growth inhibition were selected and evaluated at 250 µg/mL on PBMCs viability. Extracts showing less than 50% cytotoxicity to PBMCs were selected and IC50 and IS were determined. Strain PME-H005 presented the highest toxicity against L5178Y-R cells and the highest SI with IC50 of 39.7 µg/mL and IS \u3e 6.2, as compared with PBMCs. Four isolates that showed the highest antitumor activity were molecularly identified, corresponding to the species Penicillium citrinum, Aspergillus versicolor, Metarhizium anisopliae, and Cladosporium sp. When performing the metabolite production curve, it was observed that only A. versicolor PME-H005 and M. anisopliae PME-H007 strains retained antitumor activity, where the ethyl acetate extracts showed the highest activity with IC50 values of 23.2 µg/ mL (28 d) for the PME-H005 strain and 2.7 µg/mL (21 d) for PME-H007. Conclusions: A. versicolor PME-H005 and M. anisopliae PME-H007 strains extracts showed significant antitumor activity against L5178Y-R lymphoma cells. Further research is required to characterize bioactive compounds responsible for this activity

Soluble flagellin coimmunization attenuates Th1 priming to Salmonella and clearance by modulating dendritic cell activation and cytokine production

Soluble flagellin (sFliC) from Salmonella Typhimurium (STm) can induce a Th2 response to itself and coadministered antigens through ligation of TLR5. These properties suggest that sFliC could potentially modulate responses to Th1 antigens like live STm if both antigens are given concurrently. After coimmunization of mice with sFliC and STm there was a reduction in Th1 T\ua0cells (T-bet+IFN-γ+ CD4 T\ua0cells) compared to STm alone and there was impaired clearance of STm. In contrast, there was no significant defect in the early extrafollicular B-cell response to STm. These effects are dependent upon TLR5 and flagellin expression by STm. The mechanism for these effects is not related to IL-4 induced to sFliC but rather to the effects of sFliC coimmunization on DCs. After coimmunization with STm and sFliC, splenic DCs had a lower expression of costimulatory molecules and profoundly altered kinetics of IL-12 and TNFα expression. Ex vivo experiments using in vivo conditioned DCs confirmed the effects of sFliC were due to altered DC function during a critical window in the coordinated interplay between DCs and naïve T\ua0cells. This has marked implications for understanding how limits in Th1 priming can be achieved during infection-induced, Th1-mediated inflammation

Depredación por Podisus maculiventris (Say) sobre larvas de Choristoneura rosaceana (Harris)

Choristoneura rosaceana (Harris) es una plaga del manzano Malus domestica Borkh. de reciente aparición en México. Su control depende básicamente del uso de insecticidas químicos; sin embargo, existen registros de enemigos naturales de esta plaga que ejercen un control considerable. El objetivo del estudio fue evaluar la capacidad de depredación de Podisus maculiventris (Say) sobre C. rosaceana. Para lo anterior, en agosto y septiembre de 2014, se recolectaron 1200 larvas de C. rosaceana en huertos de manzano. Asimismo, se recolectaron 87 especímenes del depredador P. maculiventris, de diferentes estadios ninfales, de los cuales 75 se recolectaron en huertos de manzano y 17 en parcelas de maíz, además se recolectaron 22 grupos de huevos (17 en maíz y cinco en manzano). Se realizaron ensayos de consumo de P. maculiventris sobre larvas de C. rosaceana, donde el promedio fue de 0.72 larvas consumidas por día, siendo el primer estadio ninfal el que mostró un mayor promedio de consumo (1.9 larvas/día), en las primeras 24 h y el segundo estadio mostró el mayor promedio a los 7 días (1.2 larvas consumidas/día).Choristoneura rosaceana (Harris) es una plaga del manzano Malus domestica Borkh. de reciente aparición en México. Su control depende básicamente del uso de insecticidas químicos; sin embargo, existen registros de enemigos naturales de esta plaga que ejercen un control considerable. El objetivo del estudio fue evaluar la capacidad de depredación de Podisus maculiventris (Say) sobre C. rosaceana. Para lo anterior, en agosto y septiembre de 2014, se recolectaron 1200 larvas de C. rosaceana en huertos de manzano. Asimismo, se recolectaron 87 especímenes del depredador P. maculiventris, de diferentes estadios ninfales, de los cuales 75 se recolectaron en huertos de manzano y 17 en parcelas de maíz, además se recolectaron 22 grupos de huevos (17 en maíz y cinco en manzano). Se realizaron ensayos de consumo de P. maculiventris sobre larvas de C. rosaceana, donde el promedio fue de 0.72 larvas consumidas por día, siendo el primer estadio ninfal el que mostró un mayor promedio de consumo (1.9 larvas/día), en las primeras 24 h y el segundo estadio mostró el mayor promedio a los 7 días (1.2 larvas consumidas/día)

Depredación por Podisus maculiventris (Say) sobre larvas de Choristoneura rosaceana (Harris)

Choristoneura rosaceana (Harris) es una plaga del manzano Malus domestica Borkh. de reciente aparición en México. Su control depende básicamente del uso de insecticidas químicos; sin embargo, existen registros de enemigos naturales de esta plaga que ejercen un control considerable. El objetivo del estudio fue evaluar la capacidad de depredación de Podisus maculiventris (Say) sobre C. rosaceana. Para lo anterior, en agosto y septiembre de 2014, se recolectaron 1200 larvas de C. rosaceana en huertos de manzano. Asimismo, se recolectaron 87 especímenes del depredador P. maculiventris, de diferentes estadios ninfales, de los cuales 75 se recolectaron en huertos de manzano y 17 en parcelas de maíz, además se recolectaron 22 grupos de huevos (17 en maíz y cinco en manzano). Se realizaron ensayos de consumo de P. maculiventris sobre larvas de C. rosaceana, donde el promedio fue de 0.72 larvas consumidas por día, siendo el primer estadio ninfal el que mostró un mayor promedio de consumo (1.9 larvas/día), en las primeras 24 h y el segundo estadio mostró el mayor promedio a los 7 días (1.2 larvas consumidas/día).Choristoneura rosaceana (Harris) es una plaga del manzano Malus domestica Borkh. de reciente aparición en México. Su control depende básicamente del uso de insecticidas químicos; sin embargo, existen registros de enemigos naturales de esta plaga que ejercen un control considerable. El objetivo del estudio fue evaluar la capacidad de depredación de Podisus maculiventris (Say) sobre C. rosaceana. Para lo anterior, en agosto y septiembre de 2014, se recolectaron 1200 larvas de C. rosaceana en huertos de manzano. Asimismo, se recolectaron 87 especímenes del depredador P. maculiventris, de diferentes estadios ninfales, de los cuales 75 se recolectaron en huertos de manzano y 17 en parcelas de maíz, además se recolectaron 22 grupos de huevos (17 en maíz y cinco en manzano). Se realizaron ensayos de consumo de P. maculiventris sobre larvas de C. rosaceana, donde el promedio fue de 0.72 larvas consumidas por día, siendo el primer estadio ninfal el que mostró un mayor promedio de consumo (1.9 larvas/día), en las primeras 24 h y el segundo estadio mostró el mayor promedio a los 7 días (1.2 larvas consumidas/día)

CHAMPION: Chalmers Hierarchical Atomic, Molecular, Polymeric & Ionic Analysis Toolkit

We present CHAMPION: a software developed to automatically detect time-dependent bonds between atoms based on their dynamics, classify the local graph topology around them, and analyze the physicochemical properties of these topologies by statistical physics. In stark contrast to methodologies where bonds are detected based on static conditions such as cut-off distances, CHAMPION considers pairs of atoms to be bound only if they move together and act as a bound pair over time. Furthermore, the time-dependent global bond graph is possible to split into dynamically shifting connected components or subgraphs around a certain chemical motif and thereby allow the physicochemical properties of each such topology to be analyzed by statistical physics. Applicable to condensed matter and liquids in general, and electrolytes in particular, this allows both quantitative and qualitative descriptions of local structure, as well as dynamical processes such as speciation and diffusion. We present here a detailed overview of CHAMPION, including its underlying methodology, implementation and capabilities.Comment: 11 pages, 8 figure

Jak3 Is Involved in Dendritic Cell Maturation and CCR7-Dependent Migration

BACKGROUND: CCR7-mediated signalling is important for dendritic cell maturation and homing to the lymph nodes. We have previously demonstrated that Jak3 participates in the signalling pathway of CCR7 in T lymphocytes. METHODOLOGY AND PRINCIPAL FINDINGS: Here, we used Jak3(-/-) mice to analyze the role of Jak3 in CCR7-mediated dendritic cells migration and function. First, we found no differences in the generation of DCs from Jak3(-/-) bone marrow progenitors, when compared to wild type cells. However, phenotypic analysis of the bone marrow derived DCs obtained from Jak3(-/-) mice showed reduced expression of co-stimulatory molecules compared to wild type (Jak3(+/+)). In addition, when we analyzed the migration of Jak3(-/-) and Jak3(+/+) mature DCs in response to CCL19 and CCL21 chemokines, we found that the absence of Jak3 results in impaired chemotactic responses both in vitro and in vivo. Moreover, lymphocyte proliferation and contact hypersensitivity experiments showed that DC-mediated T lymphocyte activation is reduced in the absence of Jak3. CONCLUSION/SIGNIFICANCE: Altogether, our data provide strong evidence that Jak3 is important for DC maturation, migration and function, through a CCR7-mediated signalling pathway

Entamoeba lysyl-tRNA Synthetase Contains a Cytokine-Like Domain with Chemokine Activity towards Human Endothelial Cells

Immunological pressure encountered by protozoan parasites drives the selection of strategies to modulate or avoid the immune responses of their hosts. Here we show that the parasite Entamoeba histolytica has evolved a chemokine that mimics the sequence, structure, and function of the human cytokine HsEMAPII (Homo sapiens endothelial monocyte activating polypeptide II). This Entamoeba EMAPII-like polypeptide (EELP) is translated as a domain attached to two different aminoacyl-tRNA synthetases (aaRS) that are overexpressed when parasites are exposed to inflammatory signals. EELP is dispensable for the tRNA aminoacylation activity of the enzymes that harbor it, and it is cleaved from them by Entamoeba proteases to generate a standalone cytokine. Isolated EELP acts as a chemoattractant for human cells, but its cell specificity is different from that of HsEMAPII. We show that cell specificity differences between HsEMAPII and EELP can be swapped by site directed mutagenesis of only two residues in the cytokines' signal sequence. Thus, Entamoeba has evolved a functional mimic of an aaRS-associated human cytokine with modified cell specificity