Dissecting cellular crosstalk by sequencing physically interacting cells.

Area of Science:

• Cell Biology
• Genomics
• Immunology

Background:

• Cellular crosstalk is crucial for biological processes like signaling and differentiation.
• Existing single-cell genomics methods lose cell-cell interaction data after tissue dissociation.

Purpose of the Study:

• To develop and validate a novel method, sequencing physically interacting cells (PIC-seq), for analyzing molecular crosstalk between adjacent cells.
• To apply PIC-seq to map in situ cellular interactions and characterize their molecular underpinnings.

Main Methods:

• Physically interacting cells (PICs) were sorted and subjected to single-cell RNA-sequencing.
• Computational modeling was employed to systematically map cellular interactions and molecular crosstalk.
• PIC-seq was applied to immune-epithelial cell interactions in neonatal murine lungs and T cell-dendritic cell (DC) interactions in vitro and in vivo.

Main Results:

• PIC-seq successfully characterized molecular crosstalk between physically interacting cells.
• The study identified specific interaction preferences between T cells and DCs, with regulatory T cells being a major interacting subtype in lymph nodes.
• An interaction-specific molecular program between pathogen-presenting migratory DCs and T cells was discovered.

Conclusions:

• PIC-seq is a broadly applicable technology for high-resolution characterization of intercellular interaction-specific pathways.
• The method preserves crucial information on cell-cell interactions lost in traditional single-cell sequencing.
• PIC-seq offers new insights into the molecular mechanisms of cellular crosstalk in various biological contexts.