Fig. 1

Leukocyte recruitment cascade. The multistep recruitment cascade is illustrated using the example of a neutrophil. It starts with the capture of circulating neutrophils from the blood stream, followed by selectin-dependent rolling and chemokine- and integrin-dependent adhesion. After extravasation, the neutrophil follows chemokine gradients through the tissue to the point of damage/inflammation. Developmental alterations of adhesion molecule expression are indicated by footnotes as follows (fetal/premature levels were compared to those of adults): (a) L-selectin - reduced [26, 33, 37, 45, 46] and unchanged [47], E-selectin - reduced [29, 31, 38], P-selectin - reduced [29, 34, 38, 39]; (b) PSGL-1 - reduced [29, 31, 36]; (c) Mac-1 - reduced [26, 31, 36], unchanged [30, 33], and increased [37]; (d) LFA-1 - reduced [26, 45] and unchanged [30, 31, 36, 37]; (e) ICAM-1 - reduced [29, 31, 38]; (f) CXCR2 - unchanged [31]