Participation of Membrane Nanotubes in Intercellular Communication

A few years ago, a so far unknown type of intercellular connections, involved in communication was discovered. Due to their specific nano-architecture, these connections were named membrane nanotubes or tunneling nanotubes. Nanotubes ensure the transfer of both membrane and cytosolic cellular components, including organelles. Nanotubes also participate in calcium signal transduction and apoptosis signal. The length of the distance at which cells contact via nanotubes reaches several hundred micrometers. The published data suggest that nanotubes have heterogeneous structure. Among them, there are nanotubes which provide direct contact of the cytoplasm in connected cells (open-ended structure), and those, in which the transport requires overcoming a barrier, which is the cell membrane (close-ended structure). An important finding in the study of membrane nanotubes was demonstrating the ability of these connections of the intercellular transfer of pathogens, such as HIV, or abnormal form of PrP prion protein. In addition, nanotubes mediate a transport of MDR protein, involved in resistance of cancer cells to chemotherapy. It means that this type of cell connection may play an important role in the pathomechanism of AIDS, prion as well as cancer diseases.