Time-resolved assessment of single-cell protein secretion by sequencing.

Area of Science:

• Immunology
• Molecular Biology
• Genomics

Background:

• Secreted proteins are crucial for cell-to-cell communication.
• Existing methods lack the ability to simultaneously measure protein secretion, cell phenotypes, and transcriptomes at the single-cell level.

Purpose of the Study:

• To introduce a novel method, time-resolved assessment of protein secretion from single cells by sequencing (TRAPS-seq), for concurrent analysis of protein secretion and multi-omics data.
• To investigate the phenotypic and transcriptional drivers of T helper 1 (T_H1) cytokine secretion in activated T cells.

Main Methods:

• TRAPS-seq involves trapping secreted proteins on the cell surface using antibody-oligo conjugates.
• Simultaneous sequencing of cell-surface-bound protein information and intracellular transcriptomes from individual cells.
• Application to analyze the secretion of T_H1 cytokines (IFNγ, IL-2, TNF) and track secretion dynamics over time.

Main Results:

• TRAPS-seq successfully elucidated the determinants of pleiotropic T_H1 cytokine secretion in activated T cells.
• The study tracked multi-cytokine secretion dynamics, identifying unique molecular signatures governing these processes at the single-cell level.
• Early central memory T cells expressing CD45RA (T_CMRA) were identified as critical for producing and maintaining polyfunctional cytokine secretion.

Conclusions:

• TRAPS-seq provides a powerful, integrated approach for single-cell secretomics and multi-omics profiling.
• This method enables a deeper understanding of the complex regulation of protein secretion and cellular communication.
• The findings highlight the significant role of T_CMRA cells in T cell-mediated immunity and cytokine regulation.