✍🏼 Rene Yu-Hong Cheng, Joseph de Rutte, Cade Ellis K. Ito, Andee R. Ott, Lucie Bosler, Wei-Ying Kuo, Jesse Liang, Brian E. Hall, David J. Rawlings, Dino Di Carlo, Richard G. James

🏠 Center of Immunotherapy and Immunity, Seattle Children Research Institute, Seattle, WA, USA

📑 Nature Communications (2023)

Abstract
The secreted products of cells drive many functions in vivo; however, methods to link this functional information to 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 B cells and link this information to surface markers and transcriptomes from the same cells. Measurements using flow cytometry and imaging flow cytometry corroborate the association between IgG secretion and CD38/CD138. By using oligonucleotide-labeled antibodies we find that upregulation of pathways for protein localization to the endoplasmic reticulum and mitochondrial oxidative phosphorylation are most associated with high IgG secretion, and uncover surrogate plasma cell surface markers (e.g., CD59) defined by the ability to secrete IgG. Altogether, this method links quantity of secretion with single-cell sequencing (SEC-seq) and enables researchers to fully explore the links between genome and function, laying the foundation for discoveries in immunology, stem cell biology, and beyond.

How the WOLF was used in this study
The WOLF Cell Sorter was used as part of the sample preparation for linking secretory function to single-cell transcriptomes. After differentiating human B cells into antibody-secreting cells and incubating them on hydrogel nanovials to capture secreted IgG, the nanovials loaded with viable cells and labeled for surface markers and IgG secretion were sorted using the WOLF sorter to enrich the target population before loading into the 10X Genomics single-cell RNA-sequencing platform. This gentle, low-pressure sorting step helped isolate viable nanovials with cells exhibiting specific secretion and phenotypic profiles, improving the quality and relevance of the downstream single-cell transcriptomic data that linked secretion levels with gene expression signatures.