Mass Cytometry‐Based Approach for the Investigation of Stimulator of Interferon Genes Pathway

The stimulator of interferon genes (STING) pathway plays a pivotal role in innate immunity, acting as a key sensor of cytosolic DNA to initiate type-I Interferon (IFN) and pro-inflammatory cytokine production. This pathway is essential for host defence against bacterial, viral and other pathogenic threats and has emerged as a promising therapeutic target in cancer immunotherapy. However, conventional techniques such as immunoblotting and qPCR are limited in their capacity to study STING pathway activation in complex and heterogeneous biological systems, such as tumour masses or large cell populations. Here, we describe the application of mass cytometry (CyTOF) as a cutting-edge approach to characterize the STING pathway at the sub-population level. Using a high-dimensional panel of metal-labelled antibodies targeting key STING signalling components, we achieved resolution of pathway activation across diverse immune cell populations. This approach promises novel insights into cellular heterogeneity, pathway dynamics and the interplay between STING signalling and other immune pathways and underscores the power of high-dimensional analysis to overcome the limitations of traditional methods to enable a more comprehensive exploration of immune signalling pathways.