Murine mesenteric and peripheral lymph nodes: a common pool of small T cells

Abstract

GRISCELLI et al. have demonstrated¹ the existence of two populations of lymphoblasts with distinct migratory characteristics in the rat. One population was obtained from the mesenteric lymph nodes which migrate to the lamina propria of the small intestine and the other from peripheral lymph nodes which failed to migrate to the gut but were found in the spleen. These observations have been confirmed subsequently in the mouse^2–5 and in the sheep⁶. In mice the different migratory patterns of lymphoblasts of mesenteric or peripheral origin were shown to operate at the level of the T lymphoblast⁵. We have investigated whether this dichotomy extends to the migration of ⁵¹Cr-labelled small T lymphocytes and have found that less than 2% of the injected small T lymphocytes localise in the small intestine (excluding Peyer's patches) and that mesenteric and peripheral small T cells migrate equally well through mesenteric, peripheral lymph nodes and Peyer's patches. There is a slight but consistent tendency for mesenteric T cells to localise more in the liver and less in the spleen than peripheral T cells. We conclude that the distinctive migration which characterises lymphoblasts in mice does not apply to small lymphocytes.