( a the distance would be about the equi...)'Underground' tunnels discovered as means for communication between immune system cells

The authors are the first to explain the function of tunneling nanotubules, structures that were first described in fruit flies in 1998, and subsequently, identified in a handful of different types of animal and human cells.

"It's one thing to find that this intricate physical network exists but quite astonishing to learn that immune system cells are using it to relay molecular signals to one another," said Dr. Watkins, professor and vice chair, department of cell biology and physiology, and director of the Center for Biologic Imaging, University of Pittsburgh School of Medicine.

While gap junctions - interconnecting molecular bridges that conjoin tightly packed cells - are known to generate calcium signals and transport other molecules between cells, the researchers say the tunneling nanotubules are something quite different.

"This is clearly a third form of intercellular communication, distinct from gap junctions and synapses used by nerve cells. And, it is possible that tunneling nanotubules are essential for the function of the immune system, just as gap junctions are critical for the function of cardiac muscle. Exactly how this is so, we don't know," added Dr. Watkins, who also is a professor of immunology.

"Further study may help us better understand how they're involved in the local inflammatory response of the immune system. For instance, we may find that dendritic cells use this network to distribute antigens to other cells and it may be conceivable to follow the entire pathway by tracing the network of tunneling nanotubules," said Dr. Salter.

The authors' discovery builds on their recent research showing how dendritic cells respond to stimuli, but, as they freely admit in this paper, it was due in
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Source:University of Pittsburgh Medical Center