Intercellular communication through contacts between continuous pseudopodial extensions in a macrophage-like cell line.

Cell-to-cell information exchange mediated by membrane protrusions in tunneling nanotubes (TNTs) has been widely described in distinct cell lines. Here, we describe a new form of direct intercellular communication in a murine macrophage-like cell line that is mediated by pseudopodial fusions that form over scraped plastic tissue culture surfaces along scratch lines. These structures are capable of forming intercellular, tunnel-like channels (inter-pseudopodial axis connections) that can be differentiated from TNTs based on length, thickness, tandem arrangement along an axis, pseudopodial origin and permanency. These channels were able to exchange membrane lipids and contain particles 0.5 μm or lesser in diameter between cells and might represent an additional biological function of pseudopodia.