BBB seminar: Hans-Hermann Gerdes
Tunnelling nanotubes: a new type of route for intercellular communication?
Section of Biochemistry and Molecular Biology, Department of Biomedicine, University of Bergen
Mammalian cells interact with one another in a variety of ways, for example, by secreting and binding diffusible messengers like hormones and growth factors, or, between attached cells, via gap junctions. Recently, we have described what may represent an independent form of cell to cell communication that we have termed tunnelling nanotubes (TNTs). In cultures from a variety of cells we observed the formation of thin tubules (50-200 nm) connecting cells resulting in complex networks. These fragile, actin-rich structures were shown to transport membrane components from one cell to another in a uni-directional fashion. The tubules allowed the passage of vesicles of endocytic origin but excluded other organelles like mitochondria and also did not appear to allow significant transfer of cytosolic proteins. Based on these data we propose a novel biological principle of cell to cell interaction based on membrane continuity and intercellular transfer of organelles. Provided that TNTs are present in tissue they may have numerous implications in cellular processes including the intercellular spread of immunogenic material, of pathogens and of morphogens during developmental processes.