Abstract

Integrating Flow Cytometry with Next Generation Sequencing to Find Determinants of Protein Secretion

Richard James, Principal Investigator and Associate Professor, Seattle Children’s Research Institute and University of Washington

Protein secretion drives many functions in vivo; however, methods to link secretions with surface markers and transcriptomes have been lacking. By accumulating secretions close to secreting cells held within cavity-containing hydrogel nanovials, we demonstrate workflows to analyze the amount of IgG secreted from single human antibody-secreting cells and link this information to surface marker expression and transcriptional profiles from the same cells. Measurements using flow cytometry and imaging flow cytometry corroborated an association between levels of IgG secretion and CD138 expression. Using oligonucleotide-labeled antibodies and droplet-based sequencing, we show that pathways encoding protein localization to the endoplasmic reticulum, NADH complex assembly, and mitochondrial respiration were most associated with high IgG secretion. Altogether, this method links secretion information to cell surface and single-cell sequencing information (SEC-seq) and enables exploration of links between genome and secretory function, laying the foundation for numerous discoveries in immunology, stem cell biology, and beyond.