Nanotubes link immune cells

© 2005 Elsevier

Nature has once again beaten nanotechnology to the punch. Nanotubes could serve as a third form of immune-cell communication, distinct from gap junctions and synapses, says Simon Watkins at the Center for Biologic Imaging at the University of Pittsburgh School of Medicine.

Watkins and coauthor Russell Salter stumbled upon this network of nanotubes while studying how dendritic cells and macrophages responded to Escherichia coli fragments.¹ Dendritic cells responded with calcium fluxes. But when the scientists accidentally poked one macrophage with a microinjection tip, they saw calcium fluxes from its neighboring macrophages. They noticed the same in dendritic cells, but not in fibroblasts or HeLa cells.

Differential interference contrast imaging revealed up to 75 nanotubes connecting macrophages and captured calcium traveling down nanotubes from stimulated cells toward connected cells. Signals traveled as far as 500 microns at speeds of up to 35 microns per second. As a...