Functional connectivity between immune cells mediated by tunneling nanotubules

Area of Science:

• Cell Biology
• Immunology
• Cell Communication

Background:

• Intercellular communication traditionally occurs via neuronal synapses or gap junctions.
• Gap junctions facilitate the transfer of small molecules and ion fluxes, such as calcium.
• The existence of additional intercellular communication mechanisms remains an area of investigation.

Purpose of the Study:

• To investigate a novel form of cell-to-cell communication mediated by tunneling nanotubes (TNT).
• To characterize the role of TNT in signal propagation between myeloid-lineage dendritic cells and monocytes.

Main Methods:

• Live cell imaging to visualize tunneling nanotubule networks.
• Chemical and mechanical stimulation to induce calcium fluxes.
• Microinjection of dye tracers to track molecule transfer.

Main Results:

• Tunneling nanotubes (TNT) were identified as a third mode of intercellular communication.
• Calcium fluxes were rapidly propagated between dendritic cells and monocytes via TNT over hundreds of microns.
• TNT facilitated the transfer of microinjected dye tracers between connected cells.
• TNT-mediated stimulation induced lamellipodia spreading in dendritic cells, mimicking phagocytic responses.

Conclusions:

• Non-neuronal cells can communicate through a physically connected network of tunneling nanotubes (TNT).
• TNT provide a pathway for rapid, long-range signal transmission, including calcium fluxes and small molecules.
• This discovery expands the understanding of cell communication beyond synapses and gap junctions.