Microfluidics-assisted multiplexed biomarker detection for in situ mapping of immune cells in tumor sections

Because of the close interaction between tumors and the immune system, immunotherapies are nowadays considered as the most promising treatment against cancer. In order to define the diagnosis and the subsequent therapy, crucial information about the immune cells at the tumor site is needed. Indeed, different types or activation status of cells may be indicative for specific and personalized treatments. Here, we present a quantitative method to identify ten different immuno-markers in the same tumor cut section, thereby saving precious samples and enabling correlative analysis on several cell families and their activation status in a tumor microenvironment context. We designed and fabricated a microfluidic chip with optimal thermomechanical and optical properties for fast delivery of reagents on tissue slides and for fully automatic imaging by integration with an optical microscope. The multiplexing capability of the system is enabled by an optimized cyclic immunofluorescence protocol, with which we demonstrated quantitative sequential immunostaining of up to ten biomarkers on the same tissue section. Furthermore, we developed high-quality image-processing algorithms to map each cell in the entire tissue. As proof-of-concept analyses, we identified coexpression and colocalization patterns of biomarkers to classify the immune cells and their activation status. Thanks to the quantitativeness and the automation of both the experimental and analytical methods, we believe that this multiplexing approach will meet the increasing clinical need of personalized diagnostics and therapy in cancer pathology.Sensors: Microfluidic detection of multiple biomarkers for cancer immunotherapyResearchers in Switzerland have developed a chip to quickly and accurately identify different types of immune cells for cancer immunotherapy. A joint team from Ecole Polytechnique Fédérale de Lausanne and Lunaphore Technologies SA built on existing microfluidic technology to engineer a tissue processor combining microfluidic channels to deliver reagents, heating elements to control the reaction, and a viewing window above the reaction chamber. An optical microscope is used to detect fluorescently labeled immuno-markers, and the team developed image-processing algorithms to map the immune and cancer cells within the tissue samples. They tested the new system by detecting ten markers and analyzing coexpression and colocalization patterns in a lung cancer sample. Future work will increase the number of markers detected. This technology will enable clinicians to provide personalized diagnoses to cancer patients and adapt immunotherapy accordingly.