Spatial proximity sequencing maps developmental dynamics in the germinal center

Area of Science:

• Cellular and Molecular Biology
• Immunology
• Biotechnology

Background:

• Understanding cell functions within tissues requires spatial profiling of proteins and their interactions.
• Studies in signaling, immunity, and cancer critically depend on this spatial context.

Purpose of the Study:

• To introduce spatial proximity sequencing (Sprox-seq) for simultaneous, spatially resolved profiling of surface proteins, protein complexes, and mRNAs.
• To analyze tissue-wide protein interactions and their relationship with cellular architecture and states.

Main Methods:

• Spatial proximity sequencing (Sprox-seq) was developed for simultaneous profiling of proteins, protein complexes, and mRNAs.
• The method was applied to human tonsils and germinal centers, capturing molecular location.
• Analysis included mapping protein interactions, trajectories, and complexes alongside mRNA data.

Main Results:

• Sprox-seq profiled 32 proteins, 528 interactions, and thousands of mRNAs with spatial resolution.
• Protein interaction mapping recapitulated RNA architecture but showed higher complexity in germinal center light zones.
• Discovered distinct B cell state transitions and linked spatially enriched complexes with mitotic pathways.
• Captured specific cell-cell interactions, like B cell-follicular dendritic cell interactions via VLA-4-VCAM1.

Conclusions:

• Sprox-seq provides a spatially resolved, multi-modal view of cellular states and interactions within tissues.
• The method offers an integrated approach to studying protein and cellular interactions, advancing tissue biology research.