Unraveling the Unknown About the Tissue Microenvironment Using a Highly Multiplexed Technique: Imaging Mass Cytometry (OLC)

Course overview

Imaging Mass Cytometry (IMC) is a cutting-edge technique, which enables high dimensional, single-cell spatial and morphological analysis of tissue samples. IMC combines immunohistochemistry staining and rare earth metals isotope as a reporter on the antibodies against the biomarkers. The currently available techniques such as multispectral imaging and confocal microscopy enable us to study only a limited number of markers, whereas we can study up to 37 plus markers using IMC. In this study, we used an immune panel to characterize various cell populations of the lymph node tissue section to study the tissue microenvironment and spatial arrangement of various cell types. To characterize immune cells, we used CD3, CD4, FOXP3, CD8a, CD45RA, and CD45RO. Macrophages were characterized by CD68, CD11c, and CD163. Immune checkpoints, which are negative regulators of the immune system, were identified using PD1, PDL1, and LAG3. The presence of Ki67 positive cells indicated proliferation and vimentin along with collagen were used as structural markers. Together, in a single experiment, we were able to investigate more than 30 markers to distinguish various cell types along with tissue structural markers, which is impossible with conventional imaging platforms like immunohistochemistry and immunofluorescence. Imaging data generated using the IMC is highly useful to study tissue heterogeneity and spatial arrangement of the immune cell types. Furthermore, high dimensional data generated by IMC enables us to discover novel phenotypic clusters, which can be a powerful tool for the development of personalized medicine and can accelerate biomarker discovery.