B-LYMPHOCYTE BINDING TO E-SELECTIN AND P-SELECTIN IS MEDIATED THROUGHTHE DE-NOVO EXPRESSION OF CARBOHYDRATES ON IN-VITRO AND IN-VIVO ACTIVATED HUMAN B-CELLS
Aa. Postigo et al., B-LYMPHOCYTE BINDING TO E-SELECTIN AND P-SELECTIN IS MEDIATED THROUGHTHE DE-NOVO EXPRESSION OF CARBOHYDRATES ON IN-VITRO AND IN-VIVO ACTIVATED HUMAN B-CELLS, The Journal of clinical investigation, 94(4), 1994, pp. 1585-1596
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 mole
cules on both the endothelium and circulating cells. Activation of end
othelial cells (EC) with different stimuli induces the expression of s
everal adhesion molecules (E- and P-selectins, ICAM-1, VCAM-1), involv
ed in their interaction with circulating cells. In this report, we hav
e studied the binding of nonactivated and activated B cells to purifie
d E- and P-selectins. Activated but not resting B cells were able to i
nteract with both selectins. This binding capacity of activated B cell
s paralleled the induction of different carbohydrate epitopes (Lewis(x
), sialyl-Lewis(x), 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 b
y surrounding follicular dendritic cells. Moreover, the crosslinking o
f these selectin-binding epitopes resulted in an increased binding of
B cells to different integrin ligands. Thus, in addition to the involv
ement of integrins, E- and P-selectins could play an important role in
the interaction of B lymphocytes with the endothelium during B cell e
xtravasation into lymphoid tissues and inflammatory foci as well as in
their organization into lymphoid organs.