Study shows lymph node location influences maturation process of cells they contain

Based on their observations, the scientists deduced that lymph node location influences the maturation process of the cells they contain. "The cells retained their original skills for weeks following the transplant," says Dr. Sascha Cording, one of the study's first authors. "You might say lymph nodes have something like a location-specific memory."

And this in spite of the fact that all the various types of blood cells within a lymph node, including the immune cells, are constantly replaced, which means the lymph nodes' location memory must be encoded somewhere in its stroma.

Additional experiments allowed the scientists to probe just how lymph nodes obtain their memory: Following birth, both the supply of vitamin A and the intestinal bacterial microflora figure prominently into this process. Without these two influencing factors, the lymph nodes simply forget about their origin and lose their tolerogenic properties.

These findings about lymph node imprinting apply to humans as well: An inadequate supply of vitamin A after birth or meddling with the baby's developing microflora through administration of antibiotics can interfere with the lymph nodes' long-term memory. "At what age this process happens in humans we cannot as of yet pinpoint with any certainty," says H-hn. "Whether we're talking about the first few days, weeks, or months even, is difficult to surmise." The next step will be identifying the potential repercussions interfering with early imprinting of the immune system. Down the line, things like food allergies or autoimmune diseases might be the result.