Lymphocyte traffic through lymph nodes and Peyer's patches of the rat: B- and T-cell-specific migration patterns within the tissue, and their dependence on splenic tissue

Abstract

The migration routes of lymphocyte subsets through organ compartments are of importance when trying to understand the local events taking place 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 cryostat sections using immunohistochemistry. Morphometry was also performed, and the recovery of 51Cr-labeled lymphocytes in these organs was determined. B and T lymphocytes entered the lymph nodes via the high endothelial venules in similar numbers. Most B lymphocytes migrated via the paracortex (T cell area) into the cortex (B cell area), and then back in substantial numbers into the paracortex. In contrast, T lymphocytes predominantly migrated into the paracortex and were rarely seen in the cortex. No obvious differences were seen between various lymph nodes and Peyer s patches and the routes of CD4(+) and CD8(+)lymphocytes. 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 decreased, whereas CD4(+) lymphocytes migrated in larger numbers into the T cell area of both organs.

CD4+ T cells of both the naive and the memory phenotype enter rat lymph nodes and Peyer's patches via high endothelial venules: Within the tissue their migratory behavior differs

“…In agreement with earlier work using unseparated CD4' T cell populations [26,60,611, both T cell subsets localized rapidly and selectively to the Tcell compartment, and were also found in small numbers in B cell compartments (Fig. 6).…”

“…This became obvious when the number of injected T cells per area was related to the actual size of each compartment [26]. For example, 24 h after injection, the B cell compartment of cLN contained less than 5 % of the T cells present at the same time in the T cell compartment (Fig.…”

“…Since the donor T cells were derived from allotype-marked rats, they could be identified after injection into the congenic host. Quantitative immunohistochemistry [26,271 was used to investigate the interaction of naive and memory CD4' T cells with the HEV of different LN and PP, their entry into the T cell area, migration into the B cell area and their subsequent exit from the LN.…”

Splenectomy of rats selectively reduces lymphocyte function-associated antigen 1 and intercellular adhesion molecule 1 expression on B-cell subsets in blood and lymph nodes

“…This scenario is in accordance with the observation that labeled B cells with a reduced ICAM-1 expression migrate significantly faster from blood via the lymph nodes and efferent lymphatics back into the blood (present study), and the number of B cells in the thoracic duct is doubled after splenectomy. 41 Because lymph nodes contain about 40% of all B cells and the blood about 2%, 42,43 small changes in the number of B cells leaving the lymph nodes are sufficient to cause large changes in the number of B cells in the blood. It remains to be determined which cell types are involved in the interactions occurring during transmigration of the lymph nodes, 44 and whether and to what extent the migration through nonlymphoid organs such as lung, liver, and gut is affected by the changes in LFA-1 and ICAM-1 expression after splenectomy.…”

The Fate of Effector T Cells In Vivo Is Determined During Activation and Differs for CD4+ and CD8+ Cells

“…Injected effector T cells and DC in the mLN and pLN were detected via immunohistology (14). Briefly, effector mLN T cells were injected into congenic recipients.…”