Stroke affects intestinal immune cell trafficking to the central nervous system

Area of Science:

• Neuroimmunology
• Gastroenterology
• Immunology

Background:

• Stroke is an acute neurological disease with significant inflammatory components.
• The intestinal microbiota and immune cells play a role in regulating inflammation.
• While stroke alters gut immune cell populations, their trafficking dynamics remain unclear.

Purpose of the Study:

• To investigate the trafficking of gut-derived immune cells to the periphery and central nervous system (CNS) following stroke.
• To understand the dynamics of immune cell migration from the intestine after ischemic injury.

Main Methods:

• Utilized mice expressing a photoconvertible protein (Kikume Green-Red) to track immune cells.
• Photoconverted immune cells in the small intestine and analyzed their presence in lymphoid organs, meninges, and brain post-stroke (transient middle cerebral artery occlusion).

Main Results:

• Stroke significantly increased the mobilization of gut-derived immune cells (KikR+) to peripheral lymphoid organs, meninges, and brain, particularly at 3 days post-stroke.
• A notable migration of CD45hi immune cells from the gut to the brain and meninges was observed 3 days after stroke.
• Intestinal CD11c+ cells showed a preference for migrating to the brain and meninges following stroke.

Conclusions:

• Stroke enhances the trafficking of immune cells from the small intestine to both peripheral lymphoid organs and the CNS.
• These gut-derived immune cells may contribute to the inflammatory processes occurring in the brain after a stroke.