B and T lymphocyte subsets enter peripheral lymph nodes and Peyer's patches without preference in vivo: no correlation occurs between their localization in different types of high endothelial venules and the expression of CD44, VLA‐4, LFA‐1, ICAM‐1, CD2 or L‐selectin

Abstract

Many lymphocytes enter tissues such as peripheral lymph nodes, and Peyer's patches through high endothelial venules (HEV). It is known that HEV differ in the expression of adhesion molecules as lymphocyte subsets do. Through the interaction of these molecules B and T lymphocyte subsets are thought to be preferentially directed into lymphoid organs. However, it is unclear which role these mechanisms play in vivo, since there are no studies demonstrating that blood lymphocyte subsets preferentially interact with different types of HEV in vivo. Therefore, in the present study the frequency of B, T, CD4+ and CD8+ lymphocytes in the wall of the HEV of rat peripheral lymph nodes and Peyer's patches was analyzed by immunohistology. In addition, the expression of CD44, VLA-4, LFA-1, ICAM-1, CD2 and L-selectin on B and T lymphocyte subsets of the blood was determined by flow cytometry. Although B and T lymphocytes showed significantly different levels of expression for each adhesion molecule investigated, the relation of B and T lymphocytes within the HEV of peripheral lymph nodes and Peyer's patches was strikingly comparable (38.0 +/- 5.2% vs. 40.6 +/- 5.7% and 62.0 +/- 5.2% vs. 59.4 +/- 5.7%, respectively). The same was true for CD4+ and CD8+ cells. Thus, although HEV and the blood lymphocyte subsets differ markedly in their expression pattern of adhesion molecules, the existing levels are sufficient to mediate comparable entrance of B and T lymphocyte subsets into both types of HEV.

Differential migration ofin vivo primed B and T lymphocytes to lymphoid and non-lymphoid organs

“…The affinity of adhesion molecules for their ligands can be modulated by activation, accompanied by a conformational change [4]. Therefore, the homing of lymphocytes to particular tissues cannot be predicted solely on the basis of differential integrin expression [5].…”

Three-Dimensional Distribution of Intercellular Adhesion Molecule-1 on Lymphocytes in the High Endothelial Venule Analyzed by Backscatter Electron Imaging

“…According to Dustin et al [1986] ICAM-1 is expressed in germinal center cells including B cells in vivo. In a recent study a much higher ICAM-1 expression was documented on rat B lymphocytes than T cells [Westermann et al, 1994]. Simple criteria to differentiate T and B lymphocytes with scanning electron microscopy depend on the development of microvilli; B cells have a lot of microvilli [Lin et al, 1973;Polliack et al, 1974].…”

Molecular Determinants Controlling Homeostatic Recirculation and Tissue-Specific Trafficking of Lymphocytes

“…However, studies in rats by Pabst, Westermann, and others [122, 123], who used unseparated cell populations and identified each subset immunohistologically subsequent to the migration, showed that both T and B cells enter various LNs with similar kinetics and in similar numbers, although T cells express L-selectin more abundantly than do B cells in rats [122]. Given these observations, they suggested that if B cells recirculate more slowly than T cells, it might be due to the difference in the retention time of B and T cells in lymphoid tissues rather than to the efficiency of their entry [122, 123]. …”