Enteric migration of radiolabeled lymphocytes.

The migratory patterns of circulating radioisotopically labeled lymphocytes were studied by means of serial transfer into syngeneic recipients. A sub-population of ⁵¹Cr-labeled lymphocytes, defined by their property of additionally labeling with IUDR, was found to possess migrational specificity for the lamina propria of stomach, jejeunum, ileum, and large bowel. This gut-seeking population was found within peripheral nodes, mesenteric nodes, Peyer's patches, thymus, and spleen and consisted of both B and T cells. Labeled lymphocytes homed to intestine during all phases of the cell cycle, suggesting that specificity for the gut is not linked to specific events in the lymphocyte cell cycle.