[Emergency plans in crisis situations].

In November 2015, in Paris, a wave of terrorist attacks brought horror to France. The medical and nursing teams were severely tested but demonstrated efficiency and courage. The organisation of the emergency response requires fast and essential decision making and actions.

Single-cell resolution of intracellular T cell Ca dynamics in response to frequency-based HO stimulation.

Adaptive immune cells, such as T cells, integrate information from their extracellular environment through complex signaling networks with exquisite sensitivity in order to direct decisions on proliferation, apoptosis, and cytokine production. These signaling networks are reliant on the interplay between finely tuned secondary messengers, such as Ca and HO. Frequency response analysis, originally developed in control engineering, is a tool used for discerning complex networks.

Calcium Dynamics of Ex Vivo Long-Term Cultured CD8+ T Cells Are Regulated by Changes in Redox Metabolism.

T cells reach a state of replicative senescence characterized by a decreased ability to proliferate and respond to foreign antigens. Calcium release associated with TCR engagement is widely used as a surrogate measure of T cell response. Using an ex vivo culture model that partially replicates features of organismal aging, we observe that while the amplitude of Ca2+ signaling does not change with time in culture, older T cells exhibit faster Ca2+ rise and a faster decay.

Single-cell analysis of embryoid body heterogeneity using microfluidic trapping array.

The differentiation of pluripotent stem cells as embryoid bodies (EBs) remains a common method for inducing differentiation toward many lineages. However, differentiation via EBs typically yields a significant amount of heterogeneity in the cell population, as most cells differentiate simultaneously toward different lineages, while others remain undifferentiated. Moreover, physical parameters, such as the size of EBs, can modulate the heterogeneity of differentiated phenotypes due to the establishment of nutrient and oxygen gradients.

Three-dimensional in vitro tri-culture platform to investigate effects of crosstalk between mesenchymal stem cells, osteoblasts, and adipocytes.

The bone marrow niche for mesenchymal stem cells (MSCs) contains different amounts of bone and fat that vary with age and certain pathologies. How this dynamic niche environment may affect their differentiation potential and/or healing properties for clinical applications remains unknown, largely due to the lack of physiologically relevant in vitro models. We developed an enabling platform to isolate and study effects of signaling interactions between tissue-scale, laminated hydrogel modules of multiple cell types in tandem.

Imaging single-cell signaling dynamics with a deterministic high-density single-cell trap array.

Stochasticity in gene expression, protein or metabolite levels contributes to cell-cell variations, the analysis of which could lead to a better understanding of cellular processes and drug responses. Current technologies are limited in their throughput, resolution (in space, time, and tracking individual cells instead of population average) and the ability to control cellular environment. A few microfluidic tools have been developed to trap and image cells; however, in most designs available to date, there is a compromise among loading efficiency, speed, the ability to trap single cells, and density or number of trapped cells.

Predicting cytotoxic T-cell age from multivariate analysis of static and dynamic biomarkers.

Adoptive T-cell transfer therapy relies upon in vitro expansion of autologous cytotoxic T cells that are capable of tumor recognition. The success of this cell-based therapy depends on the specificity and responsiveness of the T cell clones before transfer. During ex vivo expansion, CD8+ T cells present signs of replicative senescence and loss of function.

Parallel multi-time point cell stimulation and lysis on-chip for studying early signaling events in T cell activation.

Dynamics of complex signaling networks are important to many biological problems. Quantitative data at early time points after cellular stimulation are necessary for accurate model generation. However, the large amount of data needed is often extremely time-consuming and expensive to acquire with conventional methods.