SUMMARY – Core B: Biological Analysis Core (BAC) The contribution of tissue-resident immune cells to the production of inflammatory senescence associated secretory phenotype factors and the impact on the tissue environment is unknown, precluding the understanding of immune senescence in aging and disease in tissue and organ specific context. In this project, a diverse group of experts in aging biology, immunobiology, bioengineering, cell biology, and computational biology propose a Yale murine Tissue Mapping Center for immune cell senescence (Yale-mTMC) through investigation of well- defined lineage-marked mouse models by unbiased single-cell resolution OMICS approaches aims to discover the cellular lineage of SASP producing cells and novel biomarkers that define stromal and immune-cell senescence in vivo. The Biological Analysis Core (BAC) of Yale-mTMC will create the cellular senescence- associated tissue atlases of thymus, bone marrow, spleen, PBMCs and mesenteric adipose tissue. In order to detect and characterize rare senescent cells in vivo, construct the biomolecular and cellular map of senescent cells in these tissues implicated in immune senescence, and dissect their impact on the tissue environment, the BAC will deploy and combine three categories of bioanalytical pipelines including (i) 2D and 3D Multiplexed Imaging (MI), (ii) Single Cell Analysis (SCA) of transcriptome and proteins, and (iii) Spatial Multi-Omics Sequencing (SMOS), in order to achieve the sensitivity to detect rare senescent cells, the depth to characterize the heterogeneity of senescent cells at the genome scale, and the breathe to map a wide range of cells in situ to construct the maps of senescent cells and the associated tissue microenvironments. Specifically, the BAC will pursue the following aims: (1) to provide biospecimens for analyses from lineage-marked mice with multiple biological controls and authentication of senescence-models through co-operation with murine Tissue Mapping Centers. (2) Implement an array of characterization pipelines for single-cell and spatial omics mapping of immune cell senescence and the tissue environment, and (3) to scale and standard these pipelines by increasing the assay speed and throughput in multiplex imaging and spatial multi-omics sequencing and by developing a fully integrated and standardized workflow. Yale-mTMC's BAC brings several novel animal models and unique tissue specimens that will be shared within SenNet as well as novel spatial multi-omics techniques that will enhance the analytical capability of the consortium. It will generate a multi-omics molecular and cell atlas of senescent immune cells in multiple lymphoid and non-lymphoid organs and collaborate with human SenNet teams to map and identify common senescent signatures across tissue and species.