Adhesion Molecules in Skin - Adhesion Molecules - page 284

INTRODUCTION

h e recruitment paradigm describes the movement of specii c populations of
leukocytes from the pool of cells circulating in blood across the vascular wall
and into the underlying tissue. h is process can be divided into discreet and
independently regulated steps. h e process and the primary molecules involved in
each step are summarized in Fig. 1 and Tables 1 and 2.

Fig. 1 h e multi-step paradigm for circulating leukocyte recruitment to skin. Extravasation
of leukocytes depends on the specii c interactions of multiple receptor-ligand pairs on both the
migrating leukocyte (see Table 1 ) and on the local endothelium (see Table 2) . h e sequence and
kinetics of events and the qualities of the involved molecules confer a specii c address code for the
skin homing leukocyte. (Source: RCF, unpublished.)

Table 1 Leukocyte molecules involved in endothelial adhesion and transmigration

Tethering Rolling Activation Adhesion Diapedesis Chemotaxis

Selectin Selectin CC Chemokine Integrins Integrins CC Chemokine

ligands ligands receptors LFA-1 LFA-1 receptors

PSGL-1 PSGL-1 CCR2, 3, 4 , 8, 10 MAC-1 MAC-1 CCR1, 2, 3, 4, 5,

CD43 CD43 VLA-4 6, 8, 10

CD44 CD44 IgSF

JAM C CXC Chemokine

Selectin Selectin receptor

CD62L CD62L C-type lectin CXCR3, 4

CD209

Integrin Integrin CX 3 C chemokine

VLA-4 VLA-4 receptors

CX 3 CR1

C-type lectin

CD209

Leukocytes subsets express variable adhesion receptors that will direct their accumulation at specii c endothelial sites.
h e molecules primarily involved in skin homing are listed in bold type. (Source: RCF, unpublished.)