Suchergebnisse

BACKGROUND: Multipotent progenitor cells have been harvested from different human tissues, including the bone marrow, adipose tissue, and umbilical cord blood. Previously, we identified a population of mesenchymal progenitor cells (MPCs) isolated from the traumatized muscle of patients undergoing reconstructive surgery following a war-related blast injury. These cells demonstrated the ability to differentiate into multiple mesenchymal lineages. While distal radius fractures from a civilian setting have a much lower injury mechanism (low-energy trauma), we hypothesized that debrided traumatized muscle near the fracture site would contain multipotent progenitor cells with the ability to differentiate and regenerate the injured tissue. METHODS: The traumatized muscle was debrided from the pronator quadratus in patients undergoing open reduction and internal fixation for a distal radius fracture at the Walter Reed National Military Medical Center. Using a previously described protocol for the isolation of MPCs from war-related extremity injuries, cells were harvested from the low-energy traumatized muscle samples and expanded in culture. Isolated cells were characterized by flow cytometry and q-RT-PCRs and induced to adipogenic, osteogenic, and chondrogenic differentiation. Downstream analyses consisted of lineage-specific staining and q-RT-PCR. RESULTS: Cells isolated from low-energy traumatized muscle samples were CD73+, CD90+, and CD105+ that are the characteristic of adult human mesenchymal stem cells. These cells expressed high levels of the stem cell markers OCT4 and NANOG 1-day after isolation, which was dramatically reduced over-time in monolayer culture. Following induction, lineage-specific markers were demonstrated by each specific staining and confirmed by gene expression analysis, demonstrating the ability of these cells to differentiate into adipogenic, osteogenic, and chondrogenic lineages. CONCLUSIONS: Adult multipotent progenitor cells are an essential component for the success of regenerative ...

AbstractIntroductionHIV infection causes pathological changes in the natural killer (NK) cell compartment that can be only partially restored by antiretroviral therapy (ART). We investigated NK cells phenotype and function in children with perinatally acquired HIV (PHIV) and long‐term viral control (five years) due to effective ART in a multicentre cross‐sectional European study (CARMA, EPIICAL consortium). The impact of age at ART start and viral reservoir was also evaluated.MethodsPeripheral blood mononuclear cells (PBMCs) from 40 PHIV who started ART within two years of life (early treated patients (ET), ≤6 months; late treated patients (LT), > 6 months), with at least five years of HIV‐1 suppression (<40 HIV copies/mL), were collected between November 2017 and August 2018. NK phenotype and function were analysed by flow cytometry and transcriptional profile of PBMCs by RNA‐Seq. HIV‐1 DNA was measured by real‐time polymerase chain reaction (Data were analysed by Spearman correlation plots and multivariable Poisson regression model (adjusted for baseline %CD4 and RNA HIV viral load and for age at ART start as an interaction term, either ET or LT) to explore the association between NK cell parameters and HIV reservoir modulated by age at ART start.ResultsA significantly higher frequency of CD56neg NK cells was found in LT compared with ET. We further found in LT a positive correlation of CD56neg NK cells with HIV‐1 DNA. LT also displayed increased expression of the NKG2D and NKp46 activating receptors and perforin compared with ET. Moreover, CD107a+ and IFN‐γ+ frequencies in non‐stimulated NK were associated with HIV‐1 DNA in LT patients. Finally, RNA‐Seq analysis showed in LT an up‐regulation of genes related to NK‐activating pathways and susceptibility to apoptosis compared with ET.ConclusionsWe show that early initiation of ART during infancy preserves the NK compartment and is associated with lower HIV‐1 reservoir. Such condition persists over adolescence due to long‐term viral control achieved through effective ART.