Biology subjects

Sangare, L.

Publications and source records attributed to Sangare, L..

3 recordsLinked to original sources

bioRxiv2025

Toxoplasma effector TgWIP hijacks dendritic cell actin and motility via Nck1/Grb2 and the WAVE complex

The intracellular parasite Toxoplasma gondii enhances its dissemination to distant organs by hijacking infected leukocytes via a Trojan Horse mechanism. Upon infecting dendritic cells (DCs), Toxoplasma induces a hypermigratory phenotype characterized by podosome dissolution and formation of F-actin stress fibers. We previously showed that these cytoskeletal changes depend on the effector protein Toxoplasma WAVE complex-interacting protein (TgWIP) secreted from parasites to infected leukocytes. Here, we identify the host adaptor proteins Non-catalytic region of tyrosine kinase adaptor protein 1 and 2 (Nck1/2) and Growth factor receptor-bound protein 2 (Grb2) as direct TgWIP interactors. TgWIP mainly uses two distinct proline-rich regions (PRRs) to interact with Nck1 and Grb2. Mutating these PRRs abrogates TgWIP binding to Nck1 and Grb2 and diminishes podosome dissolution and DC hypermotility. Furthermore, we show that TgWIP directly interacts with the actin nucleation promoting factor WAVE Regulatory Complex (WRC) via a WRC-interacting receptor sequence (WIRS). Disrupting this interaction also influences actin cytoskeletal remodeling and DC hypermotility. Collectively, our data reveal that TgWIP directly interacts with multiple actin regulators, including Nck1, Grb2, and the WRC, to remodel the actin cytoskeleton of the host cells, elucidating a key mechanism that Toxoplasma exploits to enhance host cell migration and dissemination.

microbiology↗

bioRxiv2019

Whatman FTA(R) cards versus plasma specimens for the quantitation of HIV-1 RNA using two Real-Time PCR assays

BackgroundSeveral studies have been conducted to compare the use DBS as alternative to plasma specimens, but mainly using Whatman 903(R) cards as filter paper. The aim of this study was to evaluate Whatman FTA(R) cards (FTA cards) specimens for HIV-1 viral load testing by comparing it to plasma specimens, using 2 real-Time PCR assays.\n\nMethodologyA cross-sectional study was conducted between April 2017 and September 2017, in HIV-1 patients admitted at Yalgado Ouedraogo teaching hospital. Paired FTA cards and plasma specimens were collected and analyzed using Abbott RealTime HIV-1 assay (Abbott) and COBAS(R) AmpliPrep/COBAS(R) TaqMan v2.0 (Roche), following manufacturers protocol.\n\nResultsA total of 107 patients were included. No Statistical differences (p-value > 0.05) were observed between the mean viral loads obtained from FTA cards and plasma specimens with Roche and Abbott assays. Twenty-nine samples with Roche and 15 samples with Abbott assay showed discrepant results. At viral loads of [≤]1000 copies/mL, the sensitivity and specificity of FTA cards were 78.6%, and 100% with Roche, and 92.3% and 95.9% with Abbott. Strong correlation was found between FTA cards and plasma specimens with both assays. With Roche, Bland-Altman analysis showed bias of -0.3 and 95% limits of agreement of -2.6 to 1.8 log10, with 97/99 cases (97.9%) within agreement limits. With Abbott, Bland-Altman analysis showed bias of -0.1 and 95% limits of agreement of -2.3 to 2.1 log10, with 96/99 cases (96.9%) within agreement limits.\n\nConclusionOur study demonstrated the feasibility of using FTA cards filter paper for HIV-1 viral load testing. However, further studies are required for FTA cards filter paper validation in HIV-1 treatment monitoring.

molecular biology↗

bioRxiv2019

Rice bran supplementation modulates growth, microbiome and metabolome in weaning infants: a clinical trial in Nicaragua and Mali

Rice bran supplementation provides nutrients, prebiotics and phytochemicals that enhance gut immunity, reduce enteric pathogens in mice and diarrhea in neonatal pigs, and warranted attention for improvement of environmental enteric dysfunction (EED) in children at risk. EED is a condition that drives childhood stunting via intestinal dysbiosis and impaired nutrient metabolism. This study investigated effects of rice bran supplementation on growth, EED biomarkers, gut microbiome and metabolome in weaning infants from 6 to 12 months old in Nicaragua and Mali. Healthy infants were randomized to a control group or rice bran group that received daily supplementation at increasing doses each month. Stool microbiomes were characterized using 16S rDNA amplicon sequencing. Stool metabolomes were analyzed using ultra-high-performance liquid-chromatography tandem mass-spectrometry. Statistical comparisons were completed at 6, 8, and 12 months of age. Daily consumption of rice bran was safe and feasible for infant growth, decreasing alpha-1 antitrypsin levels, and modulating gut microbiome and metabolome when compared to control. Rice bran merits investigation as a practical intervention strategy that could decrease EED prevalence and risk for children from low- and middle-income countries where rice is grown as a staple food, and bran is used as animal feed or wasted. One Sentence SummaryDietary rice bran supplementation during infant weaning from 6-12 months of age improved growth outcomes, modulated environmental enteric dysfunction biomarkers, and supported metabolism by the gut microbiome. The authors declare no competing financial or non financial interests to disclose as defined by Nature Research. There are also no other interests that might be perceived to influence the results and/or discussion reported in this paper. Correspondence and requests for materials should be addressed to Dr. Elizabeth Ryan (e.p.ryan@colostate.edu).

clinical trials↗