Adhesion of B cell lines to endothelial cells from human lymphoid tissue modulates tyrosine phosphorylation and endothelial cell activation

Reyes L.I.; Escobar P.; Bono M.R.; Rosemblatt, M.

Keywords: kinetics, system, growth, adhesion, endothelium, mouse, activation, animals, phosphorylation, cytokines, cytokine, cells, antigen, protein, cell, t-lymphocytes, mice, tyrosine, tumor, line, humans, transduction, human, migration, macrophage, tissue, signal, rna, immune, integrin, article, kinase, factor, production, map, paxillin, cross, lymphocyte, cd40, colony, dephosphorylation, signaling, b-lymphocytes, contact, controlled, animal, chemokine, study, 8, 1, linking, inflammatory, response, monocyte, interleukin, priority, nonhuman, journal, RNA,, Cells,, Cultured, Messenger, beta1, Antigens,, CD29, Endothelium,, 6, activated, lymphoid, tonsil, Lymphatic, Stimulating, 1beta, b, Phosphoproteins, Jurkat, mitogen, focal, Chemotactic, alpha4


Through the production of cytokines and growth factors the endothelium of secondary lymphoid organs plays a crucial role in controlling lymphocyte migration to the lymphoid microenvironment, an essential step in the initiation of the immune response. Here we demonstrate that direct contact of B cell lines with tonsil-derived human endothelial cells resulted in changes in the phosphorylation state of endothelial cells, causing their functional activation. We found a rapid (<15-s) and transient dephosphorylation, followed by a rapid rephosphorylation of tyrosine residues of the focal adhesion kinase, paxillin, and ERK2. Maximal rephosphorylation occurred after 15-30 min of B cell contact. Preincubation of lymphoid B cells with an adhesion-blocking Ab directed against ?4?1 integrin abrogated adhesion-mediated changes of endothelial cell tyrosine phosphorylation, suggesting that cell contact was essential. Similar patterns of tyrosine phosphorylation, but with slightly different kinetics were induced after cross-linking of ?1 integrin or CD40 on endothelial cells. Functional activation of endothelial cells by B cell adhesion was confirmed by the production of IL-6, IL-8, monocyte chemoattractant protein-1, M-CSF, and macrophage inflammatory protein-1? mRNA. However, direct cross-linking of ?1 integrin and CD40 failed to accomplish the same functional activation. These data indicate that direct contact of lymphoid B cells with the endothelium from lymphoid tissue induce endothelial cell signaling, resulting in chemokine and cytokine production. This phenomenon may provide a mechanism for the remodeling of the endothelium from lymphoid tissues, thus contributing to the free migration of lymphocytes and other cells into the lymphoid organs.

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Título según SCOPUS: Adhesion of B cell lines to endothelial cells from human lymphoid tissue modulates tyrosine phosphorylation and endothelial cell activation
Título de la Revista: JOURNAL OF IMMUNOLOGY
Volumen: 169
Número: 10
Fecha de publicación: 2002
Página de inicio: 5881
Página final: 5888
Idioma: English