Molecular pixelation: spatial proteomics of single cells by sequencing.

Area of Science:

• Immunology
• Proteomics
• Molecular Biology

Background:

• Cell surface protein distribution is crucial for immune system functions like cell communication and movement.
• Current fluorescence microscopy techniques lack the scalability for high-throughput, subcellular spatial proteomics.
• Understanding protein organization is key to defining cell states and functions.

Purpose of the Study:

• To introduce Molecular Pixelation (MPX), a novel optics-free method for high-resolution spatial proteomics in single cells.
• To demonstrate MPX's capability for mapping the spatial distribution of multiple proteins within individual cells.
• To explore the potential of MPX in identifying spatial patterns of protein organization in immune cells.

Main Methods:

• MPX utilizes antibody-oligonucleotide conjugates (AOCs) and DNA nanobeads to spatially tag proteins.
• AOCs are computationally assembled into local neighborhoods using DNA sequence-unique pixels, creating over 1,000 3D zones per cell.
• DNA sequencing data is processed to construct spatial proteomics networks for up to 76 proteins per cell.

Main Results:

• MPX successfully generated spatial proteomics networks for 76 proteins in single cells.
• Analysis of spatial statistics on graph representations identified known and novel protein organization patterns in chemokine-stimulated T cells.
• The study demonstrated MPX's ability to capture dynamic changes in protein spatial distribution.

Conclusions:

• Molecular Pixelation (MPX) offers a scalable, high-throughput alternative to fluorescence microscopy for spatial proteomics.
• MPX enables the discovery of subcellular protein organization patterns critical for immune cell function.
• The spatial arrangement of proteins identified by MPX can define distinct cell states, offering new insights into cellular dynamics.