161 research outputs found
Tor Vergata’s Roadmap to Open Science: Experience in Biosciences
This paper has been presented at Open Science International Staff Week celebrated in Getafe (Madrid) - November 6-8, 201
impact of human leukocyte antigen polymorphisms in human immunodeficiency virus progression in a paediatric cohort infected with a mono phyletic human immunodeficiency virus 1 strain
Objective: HLA polymorphisms within the peptide binding pocket have been associated with rapid and slowprogression to AIDS, suggesting that the capability to present efficiently HIV-1 epitopes is crucial for the infection control. To minimize the effects of genetic background due to population coming from different geographic area and viral strain variability in the cohort, an analysis of all the polymorphisms associated with the HLA-A, -B and -DR alleles has been performed in a cohort of children with a monophyletic HIV-1 infection (CRF02_AG) during an outbreak in Libya. Methods: High-resolution HLA-typing has been performed in 58 children infected with a monophyletic strain of HIV-1: 26 Long-Term Non-Progressors (LTNP), 9 Slow-Progressors (SP) and 23 Fast-Progressors (FP). HLA amino acid polymorphism frequency has been compared in the in FP respect to LTNP. Results: HLA-B resulted the most interesting locus of the study; 10 positions located in B- and F-pocket for peptidebinding have been found significant after Bonferroni's correction: 11S (LTNP=7.69% FP=34.78% OR=0.156 P<0.05), 74D (LTNP=15.38%, FP=52.17%, OR=0.167; p<0.015) and 94T (LTNP=15.38%, FP=52.17%, OR=0.045; p<0.001), resulted associated with AIDS progression; 66N (LTNP=42.31% FP=8.7% OR=7.7; p<0.02), 80I (LTNP=80.77%, FP=34.78%, OR=7.86; p<0.036), 81A (LTNP=84.61%, FP=47.83%, OR=6; p<0.015), 82L (LTNP=88.46%, FP=47.83%, OR=7.86; p<0.006) and 83R (LTNP=88.46%, FP=47.83%, OR=7.86; p<0.006), has been associated with non-progression. Further, carrying Bw4-epitope resulted associated with LTNP (phenotype-frequency: LTNP=88.46%, FP=47.83%, OR=8.36; p<0.006), with homozygosis for Bw4 (LTNP=30.8%, FP=8.7%, p<0.05) associated with delayed progression and homozygosis for Bw6 (LTNP=11.5%, FP=52.1%, p<0.05) associated with fast progression to AIDS. Conclusion: The progression to AIDS might be in part determined by the binding capability of B-pocket and F-pocket of HLA-B and in part by the interaction of NK's inhibitory receptor with HLA-B Bw4-epitope which regulate innate immune response and might have important implications for a better disease control
The Ebola virus disease outbreak in Tonkolili district, Sierra Leone: a retrospective analysis of the Viral Haemorrhagic Fever surveillance system, July 2014–June 2015
In Sierra Leone, the Ebola virus disease (EVD) outbreak occurred with substantial differences between districts with someone even not affected. To monitor the epidemic, a community event-based surveillance system was set up, collecting data into the Viral Haemorrhagic Fever (VHF) database. We analysed the VHF database of Tonkolili district to describe the epi- demiology of the EVD outbreak during July 2014–June 2015 (data availability). Multivariable analysis was used to identify risk factors for EVD, fatal EVD and barriers to healthcare access, by comparing EVD-positive vs. EVD-negative cases. Key-performance indicators for EVD response were also measured. Overall, 454 EVD-positive cases were reported. At multivariable analysis, the odds of EVD was higher among those reporting contacts with an EVD-positive/ suspected case (odds ratio (OR) 2.47; 95% confidence interval (CI) 2.44–2.50; P < 0.01) and those attending funeral (OR 1.02; 95% CI 1.01–1.04; P < 0.01). EVD cases from Kunike chief- dom had a lower odds of death (OR 0.22; 95% CI 0.08–0.44; P < 0.01) and were also more likely to be hospitalised (OR 2.34; 95% CI 1.23–4.57; P < 0.05). Only 25.1% of alerts were gen- erated within 1 day from symptom onset. EVD preparedness and response plans for Tonkolili should include social-mobilisation activities targeting Ebola/knowledge-attitudes-practice dur- ing funeral attendance, to avoid contact with suspected cases and to increase awareness on EVD symptoms, in order to reduce delays between symptom onset to alert generation and consequently improve the outbreak-response promptness
structural differences in kir3dl1 and lilrb1 interaction with hla b and the loading peptide polymorphisms in silico evidences
KIR3DL1 and LILRB1 interact with HLA class I. Using KIR3DL1/HLA-B interaction to set up the procedure, structural immune-informatics approaches have been performed in LILRB1/HLA-B alleles' combination also considering the contribution of the HLA bound peptide. All KIR3DL1 alleles interact strongly with HLA-B alleles carrying Bw4 epitope and negative charged amino acid residues in peptide position P8 disrupt KIR3DL1 binding. HLA-B alleles carrying Ile 194 show a higher strength of interaction with LILRB1 in all the analyzed haplotypes. Finally, we hypothesize a contribution of the amino acid at position 1 of the HLA bound peptide in the modulation of HLA-B/LILRB1 interaction
Structural Differences in KIR3DL1 and LILRB1 Interaction with HLA-B and the Loading Peptide Polymorphisms: In Silico
KIR3DL1 and LILRB1 interact with HLA class I. Using KIR3DL1/HLA-B interaction to set up the procedure, structural immune-informatics approaches have been performed in LILRB1/HLA-B alleles’ combination also considering the contribution of the HLA bound peptide. All KIR3DL1 alleles interact strongly with HLA-B alleles carrying Bw4 epitope and negative charged amino acid residues in peptide position P8 disrupt KIR3DL1 binding. HLA-B alleles carrying Ile 194 show a higher strength of interaction with LILRB1 in all the analyzed haplotypes. Finally, we hypothesize a contribution of the amino acid at position 1 of the HLA bound peptide in the modulation of HLA-B/LILRB1 interaction
Antioxidant and Anti-Inflammatory Activities of Extracts from Cassia alata, Eleusine indica, Eremomastax speciosa, Carica papaya and Polyscias fulva Medicinal Plants Collected in Cameroon
Abstract
Background: The vast majority of the population around the world has always used medicinal plants as first source of
health care to fight infectious and non infectious diseases. Most of these medicinal plants may have scientific evidence to be
considered in general practice.
Objective: The aim of this work was to investigate the antioxidant capacities and anti-inflammatory activities of ethanol
extracts of leaves of Cassia alata, Eleusine indica, Carica papaya, Eremomastax speciosa and the stem bark of Polyscias fulva,
collected in Cameroon.
Methods: Chemiluminescence was used to analyze the antioxidant activities of plant extracts against hydrogen peroxide or
superoxide anion. Comet assays were used to analyze the protection against antioxidant-induced DNA damage induced in
white blood cells after treating with hydrogen peroxide. Flow cytometry was used to measure cd T cells proliferation and
anti-inflammatory activity of cd T cells and of immature dendritic cells (imDC) in the presence of different concentrations of
plant extracts.
Results: Ethanol extracts showed strong antioxidant properties against both hydrogen peroxide and superoxide anion.
Cassia alata showed the highest antioxidant activity. The effect of plant extracts on cd T cells and imDC was evidenced by
the dose dependent reduction in TNF-a production in the presence of Cassia alata, Carica papaya, Eremomastax speciosa
Eleusine indica, and Polyscias fulva. cd T cells proliferation was affected to the greatest extent by Polyscias fulva.
Conclusion: These results clearly show the antioxidant capacity and anti-inflammatory activities of plant extracts collected
in Cameroon. These properties of leaves and stem bark extracts may contribute to the value for these plants in traditional
medicine and in general medical practice
Lymphocyte distribution and intrahepatic compartmentalization during HCV infection: a main role for MHC-unrestricted T cells
Hepatitis C virus (HCV) infection induces an acute and chronic liver inflammation through an immune-mediated pathway that may lead to cirrhosis and liver failure. Indeed, HCV-related hepatitis is characterized by a dramatic lymphocyte infiltrate into the liver which is mainly composed by HCV non-specific cells. Several data indicated that interferon (IFN)-gamma secretion by intrahepatic lymphocytes (IHL) may drive non-specific cell homing to the liver, inducing interferon inducible protein-10 (IP-10) production. An interesting hallmark of these IHL is the recruitment of lymphocytes associated with mechanisms of innate immunity, such as natural killer (NK), natural killer T (NKT) and gamma delta T lymphocytes. CD81 triggering on NK cell surface by the HCV envelope glycoprotein E2 was recently shown to inhibit NK cell function in the liver of HCV-infected persons, resulting in a possible mechanism contributing to the lack of virus clearance and to the establishment of chronic infection. In contrast, intrahepatic NKT cells restricted to CD1d molecules expressed on the hepatocyte surface may contribute to a large extent to liver damage. Finally, an increased frequency of T cells expressing the gamma delta T cell receptor (TCR) was observed in HCV-infected liver and recent observations indicate that intrahepatic gamma delta T cell activation could be directly induced by the HCV/E2 particle through CD81 triggering. These cells are not HCV specific, are able to kill target cells including primary hepatocytes and their ability to produce T helper (Th)1 cytokines is associated with a higher degree of liver disease. Together, CD1d/NKT and/or E2/CD81 interactions may play a major role in the establishment of HCV immunopathogenesis. In the absence of virus clearance, the chemokine-driven recruitment of lymphocytes with an innate cytotoxic behavior in the liver of HCV-infected patients may boost itself, leading to necroinflammatory and fibrotic liver disease
Micro-Vesicles of Moringa oleifera Seeds in Heterozygous Rats for DAT Gene: Effects of Oral Intake on Behavioral Profile and Hematological Parameters
Previous studies have shown multiple biological properties of Moringa oleifera, a plant native to Africa and Asia. In the present study, potential physiological properties of microvesicles extracted from Moringa oleifera seeds were assessed. For this purpose, we investigated behavioral profile and hematological parameters in a recent rat model characterized by dysregulation in dopamine transporter, a key regulator of dopaminergic system. Experimental design consisted of male Wistar-DAT rats aged between two and four months: wild-type (WT) (n = 5) and heterozygous (DATHET) (n = 4) control groups, which drank tap water; WT (n = 5) and DATHET (n = 6) groups which drank a solution of Moringa microvesicles and water (2: 68 mL per day), which was orally administered for two months. Rats were monitored for spontaneous locomotor activity on a 24/7 basis. In the early lit hours, treated DATHET subjects showed higher locomotor activity, proposing a sleep-delay effect of Moringa. In forced swimming test, WT subjects who took Moringa exhibited more depressive behavior. In DATHET rats, Moringa seemed to potentiate the struggle to find a way out, counteracting an initial panic. Hemoglobin and hematocrit underwent opposite changes in either genotype, supporting the opposite effects on behavioral phenotype observed. Future work is clearly needed to further explore these preliminary profiles
Antibacterial activity of alkaloids from Sida acuta
Sida acuta is a shrub indigenous to pantropical regions. The plant is widely used for its various pharmacological properties. Among compounds of pharmacological interest occurring in the plant, are indoloquinoline alkaloids. The aim of the present study was to investigate the antimicrobial activity of alkaloids of S. acuta from Burkina Faso. The alkaloids had a good antimicrobial activity against the test microorganisms. In the agar-well diffusion assay, highest inhibition zone diameters were recorded with Gram-positive bacteria. The broth microdilution assay gave minimal inhibitory concentration values ranging from 16 to 400 μg/ml and minimal bactericidal concentration values ranging from 80 to up to 400 μg/ml. The gas chromatography-mass spectrometry analysis of the same alkaloids led to the identification of cryptolepine and quindoline as the major components.Keywords: Cryptolepine, quindoline, indoloquinolines, antibacterial, Sida acut
Seroprevalence of Ebola virus infection in Bombali District, Sierra Leone
A serosurvey of anti-Ebola Zaire virus nucleoprotein IgG prevalence was carried out among Ebola virus disease survivors and their Community Contacts in Bombali District, Sierra Leone. Our data suggest that the specie of Ebola virus (Zaire) responsible of the 2013-2016 epidemic in West Africa may cause mild or asymptomatic infection in a proportion of cases, possibly due to an efficient immune response
- …