Mult-I-Cell-S

Cellular secreting activities, i.e. exportation of biomolecules outside of the cell, are crucial for numerous cell types (neurons, blood cells, hormone secreting cells…). In the specific case of immune responses, several biomolecules are involved in the inflammation firing processes. The characterization of these molecules production, at a single cell level is particularly relevant for both better fundamental insights understanding and for diagnostic/prognostic purposes for a more rapid and efficient identification of the inflammation triggering factors. Last but not least, this inflammation signature might also be a valuable tool in the vaccinal response tracking, either in prospective fields (search for new compounds with potential vaccine properties), or in a posteriori mode to follow vaccinal performances. The current approaches used so far either in research laboratories or in biomedical analysis laboratories for both qualitative and quantitative characterization, are mainly based on the search for these secreted products in cell supernatants upon incubation with several cells from the same sub-type or not. Such population-averaged data might be significantly different from data obtained from ‘individualized’ cells. For example, if the proteins A, B and C are found in a sample, they might be secreted by the same individual cell or by two (or three) different cell sub-types. It is not possible so far to address such questions though it might be crucial for better inflammation response understanding at idividual cell levels, and thus also ensuring a better knowledge of the immune response in general. So far, the only technique that give access to a mono-parametric analysis at a single cell level is the ELISPOT. This approach is an end-point assay and allows visualization, a posteriori, of colored ‘shadows’ were secreting cells were grown and cultured. Though some rare references exist on dual secreted targets assaying, this technique has mainly been dedicated to single target assessment. The project we are proposing is aimed at developing new tools for accessing secreting activities data at single cell levels. To that end, we plan to develop functionalized surfaces (with micrometric-large spots) enabling a 2D organization of living blood cells. These microarrays will also be functionalized with dedicated probe molecules for secreted targets capture (for one, and more importantly, for several targets produced by the same individual cell) and will be analyzed in a real-time manner during cell incubation on the biochip. This multidisciplinary program involves high level expertise in several domains such as 1) Chemistry for molecular probes handling and grafting on the biochip but also for surface treatments suitable for both complex biological sample (blood) handling and micrometric electrochemical arraying on electrodes, 2) Physics for the microarrying systems design and fabrication and also for dedicated optical detection systems developments and last but not least 3) Biology as this project was born from discussions with immunologists (characterization of medically relevant targets, sample characterization with regular techniques and also interpretation of biochip produced data, in close collaboration with the two others partners). The objective to be reached is the development of new tools for the characterization of immune responses.