Adhesion receptors involved in clustering of blood dendritic cells and T lymphocytes

Abstract

The relationship of dendritic cells (DC) isolated from the peripheral blood to those of lymphoid tissue is, in terms of maturation and function, incompletely understood. In our present study, we have explored the molecular basis of adhesion of T cells to blood DC. Analysis of the expression of adhesion receptors on the cell surface of blood DC revealed that these cells express lymphocyte function-associated antigen (LFA)-1 (CD11a/18), ICAM-1 (CD54), LFA-3 (CD58) and CD44, but are very late antigen (VLA)-4 (CD49d) and vascular cell-adhesion molecule (VCAM)-1 negative. The LFA-1 pathway was found to play a key role in T cells-blood DC adhesion; monoclonal antibodies (mAb) against both LFA-1 and ICAM-1 strongly inhibited adhesion between those cells. Moreover, a T cell clone from an LFA-1-deficient patient showed poor binding to blood DC. The important role of LFA-1 in T cell-blood DC adhesion was also supported by the metabolic energy and divalent cation dependence of the interaction. mAb against LFA-3 and CD2 did not inhibit T cell-blood DC binding. In contrast to the strong inhibition by antibodies to LFA-1 and ICAM-1, antibodies to CD44 enhanced conjugate formation between T cells and blood DC. Together, our results show that the LFA-1/ICAM-1 pathway plays a central role in T cell-blood DC adhesion, a situation like that in T cell adhesion to lymphoid DC. However, unlike lymphoid DC, blood DC do not express VCAM-1 nor use LFA-3 for T cell binding.

Opposing roles of blood myeloid and plasmacytoid dendritic cells in HIV-1 infection of T cells: transmission facilitation versus replication inhibition

“…LFA-1 is expressed on T cells, but can also be found on DCs. 34 However, we found no differences in LFA-1 expression either ( Figure 3D). To confirm our previous work on the importance of the ICAM-1-LFA-1 interaction, blocking antibodies were used to test the importance of this molecule in HIV-1 transmission by blood MDCs.…”

Cutting Edge: CCR4 Mediates Antigen-Primed T Cell Binding to Activated Dendritic Cells

“…In order for the immunological synapse to form, the T cell must transition from a migratory to a stationary state. Adhesive interactions between the T cell and DC, in part stimulated by engagement of the TCR (5,6), have been reported to be mediated by several adhesion molecules and their corresponding receptors, which include LFA-1/ICAM-1,-2, -3, CD2/LFA-3, and DC-SIGN/ICAM-3 (7)(8)(9)(10).…”

Vascular cell adhesion molecule 1: contrasting transcriptional control mechanisms in muscle and endothelium.

“…Through its interaction with the integrin receptor a4f31 (4)-and also perhaps a4f37 (5)-on T cells, monocytes, and eosinophils, VCAM-1 targets these immune cells to cytokinestimulated endothelium (1,(6)(7)(8)(9)(10)(11)(12). VCAM-1 and a431 mediate cell-cell interactions which are important for skeletal muscle differentiation (13).…”