Recirculation of lymphocyte subsets (CD5+, CD4+, CD8+, SBU-T19+ and B cells) through gut and peripheral lymph nodes.

The surface phenotypes (CD5+, CD4+, CD8+, SBU-T19+, MHC class II+, T80+ and sIg+) of lymphocytes in blood, and in prescapular and ileocaecal efferent lymph of sheep, have been determined. The similarity in the distribution of lymphocyte subsets in both lymph compartments indicated that the non-random migration of lymphocyte populations to peripheral lymph nodes and gut could not be due to preferential migration of a particular lymphocyte subset such as CD4+ or CD8+ cells to one tissue. Marked differences in the percentage of lymphocyte subsets between blood and efferent lymph suggested that some lymphocyte subsets leave the blood with differing efficiencies and that differential extraction of lymphocyte subsets from blood by a lymph node may be due to subset-specific lymphocyte-endothelial interactions.