LYMPHOCYTE TRAFFIC THROUGH LYMPH-NODES AND PEYERS-PATCHES OF THE RAT - B-CELL-SPECIFIC AND T-CELL-SPECIFIC MIGRATION PATTERNS WITHIN THE TISSUE, AND THEIR DEPENDENCE ON SPLENIC TISSUE

The migration routes of lymphocyte subsets through organ compartments are of importance when try ing to understand the local events taking p lace during immune responses. We have therefore studied the traffic of B, T, CD4(+), and CD8(+) lymphocytes through lymph nodes and Peyer's patches. At various time points after injection into the rat, labeled lymphocytes were localized, and their phenotype characterized in cryos tat sections using immunohistochemistry. Morphometry was also performe d, and the recovery of Cr-51-labeled lymphocytes in these organs was d etermined. B and T lymphocytes entered the lymph nodes via the high en dothelial venules in similar numbers. Most B lymphocytes migrated via the paracortex (T cell area) into the cortex (B cell area), and then b ack in substantial numbers into the paracortex. In contrast, T lymphoc ytes predominantly migrated into the paracortex and were rarely seen i n the cortex. No obvious differences were seen between various lymph n odes and Peyer's patches and the routes of CD4(+) and CD8(+) lymphocyt es. After injection of lymphocytes into animals with autotransplanted splenic tissue, the number of B lymphocytes that had migrated into the B cell area of lymph nodes and of Peyer's patches was significantly d ecreased, whereas CD4(+) lymphocytes migrated in larger numbers into t he T cell area of both organs.