Development of a unified mass cytometry assay integrating activation-induced markers (AIMs) and cytokine profiling for high-throughput assessment of antigen-specific T cell responses

Accurate profiling of antigen-specific T cells by measuring T cell activation markers and cytokine production has been limited by inconsistent marker usage across studies and substantial methodological variability. To overcome these challenges, we established a unified mass cytometry (CyTOF) platform that integrates optimized activation-induced marker (AIM) panels, intracellular cytokine staining (ICS), and a cadmium-based barcoding system for high-throughput, multiplexed analysis of T cell responses. We optimized stimulation conditions (18-24 h) and validated highly sensitive dual AIM combinations, including CD25⁺CD134⁺ and CD25⁺CD69⁺ in CD4⁺ T cells, as well as CD25⁺CD137⁺ and CD25⁺CD69⁺ in CD8⁺ T cells. These combinations were stable under protein transport inhibition and closely paralleled cytokine-producing populations. In addition, we developed a cadmium-tagged β2 M/CD298 barcoding strategy that supports 21-plex sample processing without signal distortion. Validation in two independent cohorts confirmed the platform's high sensitivity, reproducibility, and its ability to simultaneously detect AIM⁺ T cells and cytokine-producing subsets. Together, this integrated workflow provides a robust and scalable framework for comprehensive immune monitoring in vaccine development and infectious disease research.