B lymphocyte binding to E- and P-selectins is mediated through the de novo expression of carbohydrates on in vitro and in vivo activated human B cells.
Cell adhesion to endothelium regulates the trafficking and recruitment of leukocytes towards lymphoid organs and sites of inflammation. This phenomenon is mediated by the expression of a number of adhesion molecules on both the endothelium and circulating cells. Activation of endothelial cells (EC) with different stimuli induces the expression of several adhesion molecules (E- and P-selectins, ICAM-1, VCAM-1), involved in their interaction with circulating cells. In this report, we have studied the binding of nonactivated and activated B cells to purified E- and P-selectins. Activated but not resting B cells were able to interact with both selectins. This binding capacity of activated B cells paralleled the induction of different carbohydrate epitopes (Lewisx, sialyl-Lewisx, CD57 and CDw65) as well as other molecules bearing these or related epitopes in myeloid cells (L-selectin, alpha L beta 2 and alpha X beta 2 integrins, and CD35) involved in the interaction of different cell types with selectins. B cells infiltrating inflamed tissues like in Hashimoto's thyroiditis, also expressed these selectin-binding carbohydrates in parallel with the expression of E-selectin by surrounding follicular dendritic cells. Moreover, the crosslinking of these selectin-binding epitopes resulted in an increased binding of B cells to different integrin ligands. Thus, in addition to the involvement of integrins, E- and P-selectins could play an important role in the interaction of B lymphocytes with the endothelium during B cell extravasation into lymphoid tissues and inflammatory foci as well as in their organization into lymphoid organs.
Postigo
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AA
Servicio de Inmunología, Hospital de la Princesa, Universidad Autonoma de Madrid, Spain.
Marazuela
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M
Sánchez-Madrid
F
F
de Landázuri
M O
MO
D001402:B-Lymphocytes / Q000378:metabolism*; D001483:Base Sequence; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000096:biosynthesis*; D002448:Cell Adhesion / Q000502:physiology*; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002478:Cells, Cultured; D019040:E-Selectin; D004790:Enzyme Induction; D000939:Epitopes / Q000096:biosynthesis / Q000378:metabolism; D005647:Fucosyltransferases / Q000096:biosynthesis; D006801:Humans; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000378:metabolism; D008969:Molecular Sequence Data; D019007:P-Selectin; D014066:Palatine Tonsil / Q000166:cytology; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D013967:Thyroiditis, Autoimmune / Q000378:metabolism
D002241:Carbohydrates; D015815:Cell Adhesion Molecules; D019040:E-Selectin; D000939:Epitopes; D008562:Membrane Glycoproteins; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins; D012333:RNA, Messenger; D005647:Fucosyltransferases