Single cell immune profiling of cryopreserved whole blood and reversibly fixed PBMCs from healthy donors reveals T cell expansions biasde towards putative SARS-CoV-2 epitopes 3259

Abstract Description Cryopreservation of PBMCs is the gold standard for cell storage, but increases upfront logistical complexity. Here, we showcase two alternative methods for sample preservation: direct cryopreservation of whole blood and reversible fixation of enriched PBMCs. Single cell sequencing with V(D)J immune profiling demonstrates that these methods yield comparable gene detection, cell type proportions, and clonotype discovery to standard cryopreservation storage. T cell receptor sequencing reveals expanded T cell clonotypes in two healthy human donors. Screening TCR sequences against the Immune Epitope Database indicates a bias towards putative SARS-CoV-2 epitopes. Single cell genomics tools are transforming biomedical research, but logistical issues with blood transport and processing limit their clinical utility. We developed workflows for whole blood cryopreservation and reversible PBMC fixation with off-the-shelf reagents for single cell genomics assays. Paired with high-throughput and automatable immunomagnetic bead-based cell enrichment, these workflows increase experimental flexibility and enable batch processing. Validated using blood samples from individuals with a range of cancers, autoimmune disorders, and no reported conditions, these workflows are ready for application in clinical research. Topic Categories Technological Innovations in Immunology (TECH)