Suchergebnisse

Changes in the human gastrointestinal microbiome are associated with several diseases. To infer causality, experiments in representative models are essential, but widely used animal models exhibit limitations. Here we present a modular, microfluidics-based model (HuMiX, human-microbial crosstalk), which allows co-culture of human and microbial cells under conditions representative of the gastrointestinal human-microbe interface. We demonstrate the ability of HuMiX to recapitulate in vivo transcriptional, metabolic and immunological responses in human intestinal epithelial cells following their co-culture with the commensal Lactobacillus rhamnosus GG (LGG) grown under anaerobic conditions. In addition, we show that the co-culture of human epithelial cells with the obligate anaerobe Bacteroides caccae and LGG results in a transcriptional response, which is distinct from that of a co-culture solely comprising LGG. HuMiX facilitates investigations of host-microbe molecular interactions and provides insights into a range of fundamental research questions linking the gastrointestinal microbiome to human health and disease. ; We thank the scientists and technical staff of the Luxembourg Centre for Systems Biomedicine and Center for Applied Nanobioscience and Medicine, particularly Matthew Barrett and Brett Duane for their excellent technical assistance and engineering support. We are grateful to Francois Bernardin, Nathalie Nicot and Laurent Vallar for the microarray analysis; Aidos Baumuratov for imaging support; Linda Wampach for HuMiX illustrations; and Anna Heintz-Buschart for fruitful discussions. This work was supported by an ATTRACT programme grant (ATTRACT/A09/03), a CORE programme grant (CORE/11/BM/1186762), a European Union Joint Programming in Neurodegenerative Diseases grant (INTER/JPND/12/01) and a Proof-of-Concept grant (PoC-15/11014639) to P.W., Accompany Measures mobility grant (12/AM2c/05) to P.W. and P.S., an INTER mobility grant to P.S. (INTER/14/7516918), and an Aide a la Formation Recherche (AFR) postdoctoral grant (AFR/PDR 2013-1/BM/5821107) as well as a CORE programme grant (CORE/14/BM/8066232) to J.V.F., all funded by the Luxembourg National Research Fund (FNR). This work was further supported by a grant attributed to C.S.-D. by the 'Fondation Recherche sur le SIDA du Luxembourg'. Bioinformatics analyses presented in this paper were carried out in part using the HPC facilities of the University of Luxembourg (http://hpc.uni.lu). ; This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.

AbstractIntroductionThe chemokine receptor CCR5 is the main co‐receptor for R5‐tropic HIV‐1 variants. We have previously described a novel 24‐base pair deletion in the coding region of CCR5 among individuals from Rwanda. Here, we investigated the prevalence of hCCR5Δ24 in different cohorts and its impact on CCR5 expression and HIV‐1 infection in vitro.MethodsWe screened hCCR5Δ24 in a total of 3232 individuals which were either HIV‐1 uninfected, high‐risk HIV‐1 seronegative and seropositive partners from serodiscordant couples, Long‐Term Survivors, or HIV‐1 infected volunteers from Africa (Rwanda, Kenya, Guinea‐Conakry) and Luxembourg, using a real‐time PCR assay. The role of the 24‐base pair deletion on CCR5 expression and HIV infection was assessed in cell lines and PBMC using mRNA quantification, confocal analysis, flow and imaging cytometry.Results and DiscussionAmong the 1661 patients from Rwanda, 12 individuals were heterozygous for hCCR5Δ24 but none were homozygous. Although heterozygosity for this allele may not confer complete resistance to HIV‐1 infection, the prevalence of the mutation was 2.41% (95%CI: 0.43; 8.37) in 83 Long‐Term Survivors (LTS) and 0.99% (95%CI: 0.45; 2.14) in 613 HIV‐1 exposed seronegative members as compared with 0.35% (95% Cl: 0.06; 1.25) in 579 HIV‐1 seropositive members. The prevalence of hCCR5Δ24 was 0.55% (95%CI: 0.15; 1.69) in 547 infants from Kenya but the mutation was not detected in 224 infants from Guinea‐Conakry nor in 800 Caucasian individuals from Luxembourg. Expression of hCCR5Δ24 in cell lines and PBMC showed that the hCCR5Δ24 protein is stably expressed but is not transported to the plasma membrane due to a conformational change. Instead, the mutant receptor was retained intracellularly, colocalized with an endoplasmic reticulum marker and did not mediate HIV‐1 infection. Co‐transfection of hCCR5Δ24 and wtCCR5 did not indicate a transdominant negative effect of CCR5Δ24 on wtCCR5.ConclusionsOur findings indicate that hCCR5Δ24 is not expressed at the cell surface. This could explain the higher prevalence of the heterozygous hCCR5Δ24 in LTS and HIV‐1 exposed seronegative members from serodiscordant couples. Our data suggest an East‐African localization of this deletion, which needs to be confirmed in larger cohorts from African and non‐African countries.

AbstractIntroduction: Lopinavir/ritonavir‐based antiretroviral therapy (ART) is recommended for all HIV‐infected children less than three years. However, little is known about its field implementation and effectiveness in West Africa. We assessed the 12‐month response to lopinavir/ritonavir‐based antiretroviral therapy in a cohort of West African children treated before the age of two years.Methods: HIV‐1‐infected, ART‐naive except for a prevention of mother‐to‐child transmission (PMTCT), tuberculosis‐free, and less than two years of age children with parent's consent were enrolled in a 12‐month prospective therapeutic cohort with lopinavir/ritonavir ART and cotrimoxazole prophylaxis in Ouagadougou and Abidjan. Virological suppression (VS) at 12 months (viral load [VL] <500 copies/mL) and its correlates were assessed.Results: Between May 2011 and January 2013, 156 children initiated ART at a median age of 13.9 months (interquartile range: 7.8–18.4); 63% were from Abidjan; 53% were girls; 37% were not exposed to any PMTCT intervention or maternal ART; mother was the main caregiver in 81%; 61% were classified World Health Organization Stage 3 to 4. After 12 months on ART, 11 children had died (7%), 5 were lost‐to‐follow‐up/withdrew (3%), and VS was achieved in 109: 70% of children enrolled and 78% of those followed‐up. When adjusting for country and gender, the access to tap water at home versus none (adjusted odds ratio (aOR): 2.75, 95% confidence interval (CI): 1.09–6.94), the mother as the main caregiver versus the father (aOR: 2.82, 95% CI: 1.03–7.71), and the increase of CD4 percentage greater than 10% between inclusion and 6 months versus <10% (aOR: 2.55, 95% CI: 1.05–6.18) were significantly associated with a higher rate of VS. At 12 months, 28 out of 29 children with VL ≥1000 copies/mL had a resistance genotype test: 21 (75%) had ≥1 antiretroviral (ARV) resistance (61% to lamivudine, 29% to efavirenz, and 4% to zidovudine and lopinavir/ritonavir), of which 11 (52%) existed before ART initiation.Conclusions: Twelve‐month VS rate on lopinavir/ritonavir‐based ART was high, comparable to those in Africa or high‐income countries. The father as the main child caregiver and lack of access to tap water are risk factors for viral failure and justify a special caution to improve adherence in these easy‐to‐identify situations before ART initiation. Public health challenges remain to optimize outcomes in children with earlier ART initiation in West Africa.

All-oral direct-acting antiviral drugs (DAAs) for hepatitis C virus, which have response rates of 95% or more, represent a major clinical advance. However, the high list price of DAAs has led many governments to restrict their reimbursement. We reviewed the availability of, and national criteria for, interferon-free DAA reimbursement among countries in the European Union and European Economic Area, and Switzerland. Reimbursement documentation was reviewed between Nov 18, 2016, and Aug 1, 2017. Primary outcomes were fibrosis stage, drug or alcohol use, prescriber type, and HIV co-infection restrictions. Among the 35 European countries and jurisdictions included, the most commonly reimbursed DAA was ombitasvir, paritaprevir, and ritonavir, with dasabuvir, and with or without ribavirin (33 [94%] countries and jurisdictions). 16 (46%) countries and jurisdictions required patients to have fibrosis at stage F2 or higher, 29 (83%) had no listed restrictions based on drug or alcohol use, 33 (94%) required a specialist prescriber, and 34 (97%) had no additional restrictions for people co-infected with HIV and hepatitis C virus. These findings have implications for meeting WHO targets, with evidence of some countries not following the 2016 hepatitis C virus treatment guidelines by the European Association for the Study of Liver.

All-oral direct-acting antiviral drugs (DAAs) for hepatitis C virus, which have response rates of 95% or more, represent a major clinical advance. However, the high list price of DAAs has led many governments to restrict their reimbursement. We reviewed the availability of, and national criteria for, interferon-free DAA reimbursement among countries in the European Union and European Economic Area, and Switzerland. Reimbursement documentation was reviewed between Nov 18, 2016, and Aug 1, 2017. Primary outcomes were fibrosis stage, drug or alcohol use, prescriber type, and HIV co-infection restrictions. Among the 35 European countries and jurisdictions included, the most commonly reimbursed DAA was ombitasvir, paritaprevir, and ritonavir, with dasabuvir, and with or without ribavirin (33 [94%] countries and jurisdictions). 16 (46%) countries and jurisdictions required patients to have fibrosis at stage F2 or higher, 29 (83%) had no listed restrictions based on drug or alcohol use, 33 (94%) required a specialist prescriber, and 34 (97%) had no additional restrictions for people co-infected with HIV and hepatitis C virus. These findings have implications for meeting WHO targets, with evidence of some countries not following the 2016 hepatitis C virus treatment guidelines by the European Association for the Study of Liver.

All-oral direct-acting antiviral drugs (DAAs) for hepatitis C virus, which have response rates of 95% or more, represent a major clinical advance. However, the high list price of DAAs has led many governments to restrict their reimbursement. We reviewed the availability of, and national criteria for, interferon-free DAA reimbursement among countries in the European Union and European Economic Area, and Switzerland. Reimbursement documentation was reviewed between Nov 18, 2016, and Aug 1, 2017. Primary outcomes were fibrosis stage, drug or alcohol use, prescriber type, and HIV co-infection restrictions. Among the 35 European countries and jurisdictions included, the most commonly reimbursed DAA was ombitasvir, paritaprevir, and ritonavir, with dasabuvir, and with or without ribavirin (33 [94%] countries and jurisdictions). 16 (46%) countries and jurisdictions required patients to have fibrosis at stage F2 or higher, 29 (83%) had no listed restrictions based on drug or alcohol use, 33 (94%) required a specialist prescriber, and 34 (97%) had no additional restrictions for people co-infected with HIV and hepatitis C virus. These findings have implications for meeting WHO targets, with evidence of some countries not following the 2016 hepatitis C virus treatment guidelines by the European Association for the Study of Liver.