Tunneling Nanotubes and the Eye: Intercellular Communication and Implications for Ocular Health and Disease

Figure 2

Cytonemes and tunneling nanotubes. (a) Cytonemes were originally identified in Drosophila imaginal discs but have also been detected in developing chick limb buds. These cellular structures transport ligands and receptors over long distances from one cell to another in the complex tissue environment. Ligands cluster at the tip of a cytoneme and interact with clustered receptors on the surface of the recipient cell. (b) Tunneling nanotubes (TNTs) transport cellular organelles such as mitochondria, endosomes, and lysosomes, as well as other cargoes such as viruses, prions, and Ca²⁺ signals. TNTs form a tube through which these cargoes are directly transported between cells.

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