A new traffic route for immune cells along the body's highways is presented in the May issue of Nature Immunology.
Previously it was believed T cells, a type of immune cell, must circulate through specialized structures before migrating to pathogen-infected tissues. Eugene Butcher and colleagues now demonstrate that some T cells bypass this normal trafficking route and instead can proceed directly to the intestine where the T cells become poised to battle any invading microbes.
Because the intestine is constantly exposed to pathogenic microbes, it requires rigorous patrolling by the immune system. Accordingly, over one billion T cells are found in the human small intestine.
This direct freeway to the intestine may therefore ensure that this defense battalion is constantly replenished with fresh fighters able to take up arms against an array of pathogens.
Eugene C. Butcher (Stanford University School of Medicine, Stanford, California USA)
Abstract available online.
(C) Nature Immunology press release.
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