PROJECT SUMMARY In this renewal application, the Scientific Core (Core B) will continue to build upon the strengths of the Human Immune Monitoring Center (HIMC) and the assays developed during the initial grant period. The HIMC is an ideal environment for standardization, technology development, and data analysis, and has built an array of high-throughput and high-content assays that are unparalleled in a single center and institution. Over the initial funding period, the Scientific Core added to this menu of technologies with unique CyTOF panels and combined TCRseq/gene expression assays at the single-cell level. Over the proposed next funding period, Core B will continue to provide standardized immunological assays across studies within the U19 project, focusing on single-cell assays of allergen-responsive cells and global immune profiling. It will also continue to develop novel approaches and work with the individual projects to mine the immunological data generated. The specific aims are: 1. To provide standardized immune monitoring assays across projects. These will include detailed immunophenotyping of whole blood and PBMCs by mass cytometry (CyTOF), including a basophil-centric CyTOF panel developed in the lab of Sean Bendall (Co-Investigator of Core B). The Core will also offer 62- plex Luminex cytokine arrays to assess serum and cell supernatants for Th1/Th2/Th17 cytokines and single- cell TCRseq+gene expression for allergen-specific T cells. Finally, the Core will perform Multiplexed Ion Beam Imaging (MIBI) of esophageal, gastric and duodenal biopsy specimens, in the lab of Robert Angelo (Co-Investigator of Core B). By using the same standardized assays across all cohorts, we will greatly increase the power to test hypotheses related to any of the readouts of these assays. 2. To develop novel immune monitoring assays with individual projects. The CyTOF, MIBI, and TCRseq panels will continue to be developed based on new knowledge generated within the projects, as well as key observations made in the allergy field generally. We also plan to offer a new immunoassay platform, SomaScan from SomaLogic, for 1300 soluble protein analytes, as an additional discovery tool. 3. To facilitate mining of immune monitoring data. Using Stanford Data Miner (SDM), the Core will work with the Data Management and Analysis Core C to mine data using bioinformatics tools. SDM will provide a structured framework for extracting laboratory data linked to clinical and demographic variables, facilitating data mining and reducing the possibility of errors.