Use of intercellular proximity labeling to quantify and decipher cell-cell interactions directed by diversified...

Area of Science:

• Immunology
• Cell Biology
• Biochemistry

Background:

• Cell-cell interactions (CCIs) are crucial for immune responses.
• Existing methods struggle to capture dynamic and complex CCIs, especially in heterogeneous samples.
• FucoID (fucosyltransferase-mediated proximity labeling) offers a novel approach to study CCIs.

Purpose of the Study:

• To leverage and expand the FucoID technique for studying diverse CCIs.
• To investigate CCIs involving programmed cell death protein-1 (PD-1)/programmed cell death protein-ligand-1 (PD-L1) interactions.
• To identify previously uncharacterized CCIs, such as those between dendritic cells (DCs) and B cells.

Main Methods:

• Utilized FucoID with cell surface-anchored fucosyltransferase (FT) to label interacting cells.
• Applied FucoID to study known CCIs (e.g., PD-1/PD-L1) and unknown CCIs (e.g., DC-B cell interactions).
• Developed and synthesized site-specific antibody-based FT conjugates to enhance FucoID in complex and unpurified samples.

Main Results:

• Successfully applied FucoID to identify molecular pairs mediating CCIs, including PD-1/PD-L1.
• Discovered and characterized novel CCIs, such as those between DCs and B cells.
• Demonstrated improved FucoID performance in complex systems and clinical samples using antibody-FT conjugates.

Conclusions:

• FucoID is a versatile and powerful tool for dissecting CCIs at molecular resolution.
• The enhanced FucoID approach enables the study of CCIs in complex biological systems and clinical settings.
• This technique has broad applicability for discovering and characterizing unknown cell-cell interactions.