Processing of blood samples influences PBMC viability and outcome of cell-mediated immune responses in antiretroviral therapy-naïve HIV-1-infected patients

AbstractIntracellular cytokine staining (ICS) assay is increasingly used in vaccine clinical trials to measure antigen-specific T-cell mediated immune (CMI) responses in cryopreserved peripheral blood mononuclear cells (PBMCs) and whole blood. However, recent observations indicate that several parameters involved in blood processing can impact PBMC viability and CMI responses, especially in antiretroviral therapy (ART)-naïve HIV-1-infected individuals.In this phase I study (NCT01610427), we collected blood samples from 22 ART-naïve HIV-1-infected adults. PBMCs were isolated and processed for ICS assay. The individual and combined effects of the following parameters were investigated: time between blood collection and PBMC processing (time-to-process: 2, 7 or 24h); time between PBMC thawing and initiation of in vitro stimulation with HIV-1 antigens (resting-time: 0, 2, 6 and 18h); and duration of antigen-stimulation in PBMC cultures (stimulation-time: 6h or overnight). The cell recovery after thawing, cell viability after ICS and magnitude of HIV-specific CD8+ T-cell responses were considered to determine the optimal combination of process conditions. The impact of time-to-process (2 or 4h) on HIV-specific CD8+ T-cell responses was also assessed in a whole blood ICS assay.A higher quality of cells in terms of recovery and viability (up to 81% and >80% respectively) was obtained with shorter time-to-process (less than 7h) and resting-time (less than 2h) intervals. Longer (overnight) rather than shorter (6h) stimulation-time intervals increased the frequency of CD8+-specific T-cell responses using ICS in PBMCs without change of the functionality. The CD8+ specific T-cell responses detected using fresh whole blood showed a good correlation with the responses detected using frozen PBMCs.Our results support the need of standardized procedures for the evaluation of CMI responses, especially in HIV-1-infected, ART-naïve patients

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La place des matériaux organiques dans le mobilier de la tombe princière de Lavau (Aube) : premiers résultats

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La place des matériaux organiques dans le mobilier de la tombe princière de Lavau (Aube) : premiers résultats

International audienc

La place des matériaux organiques dans le mobilier de la tombe princière de Lavau (Aube) : premiers résultats

International audienc

Influence of texture and microstructure on the reactivity of aluminum powders

International audienceAluminum powders are commonly used in energetics materials and it is possible to improve their reactivity by preparing them as nanopowders. In this article, it is shown that high-energy ball milling can be used to tune the reactivity of nanoflakes. Several nanopowders are synthesized using three different grinding ball diameters (5 mm, 10 mm and 15 mm). The powders are characterized in terms of morphology, structure and microstructure. Changing the diameter of the grinding balls results in powders with different characteristics. Among the three diameters used, an optimum is found for powders synthetized with 10 mm diameter balls: they possess the highest specific area, the smallest aluminum crystallites and the lowest amount of deformation. The reactivity of the various nanopowders, evaluated using thermal analysis under air, is shown to be dependent on both textural and microstructural properties of the powders. Such considerations on the microstructural properties of nanopowders are of utmost importance in the quest for the best materials for energetics applications

Interface Type on Noninvasive Ventilation Efficacy in Patients With Neuromuscular Disease : A Randomized Cross-Over Trial

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