Do olfactory ensheathing cells play a role in the defense of the brain against infection?

Olfactory ensheathing cells (OECs), also known as olfactory neuroglia, are widely accepted to play a role in the ontogeny of the primary olfactory pathway. Their expression of numerous growth factors and extracellular matrix molecules is consistent with a role in guiding elongating olfactory axons from the nasal cavity to their termination in the olfactory bulb. In recent years, researchers have attempted to exploit these phenotypic features by utilizing these cells as a therapeutic agent to induce repair of the injured nervous system. However, their strategic placement along olfactory nerves, spanning the region between the external nasal cavity and the olfactory bulb (part of the central nervous system), and their expression profile of immunomodulatory proteins support a possible involvement in the protection of the brain against infection. This commentary will briefly outline the relationship between OECs and developing olfactory nerves, and recent experimental evidence that suggests a remarkable functional plasticity of OECs including a possible active role in the immune system. Copyright © 2005 S. Karger AG.