Cell-surface enzymes in control of leukocyte trafficking.
Leukocyte trafficking between the blood and the tissues is pivotal for normal immune responses. Cell-adhesion molecules (such as selectins and leukocyte integrins) and chemoattractants (such as chemokines) have well-established roles in supporting leukocyte exit from the blood. Emerging data now show that, for both leukocytes and endothelial cells, enzymatic reactions that are catalysed by cell-surface-expressed enzymes with catalytic domains outside the plasma membrane (known as ectoenzymes) also make crucial contributions to this process. Ectoenzymes can function physically as adhesion receptors and can regulate the recruitment of cells through their catalytic activities. Here, we provide new insights into how ectoenzymes--including nucleotidases, cyclases, ADP-ribosyltransferases, peptidases, proteases and oxidases--guide leukocyte traffic.
Salmi
Marko
M
MediCity Research Laboratory, University of Turku, Tykistökatu 6A, 20520 Turku, Finland. marko.salmi@utu.fi
Jalkanen
Sirpa
S
D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology*; D002634:Chemotaxis, Leukocyte / Q000502:physiology*; D004730:Endothelium, Vascular / Q000378:metabolism; D006801:Humans
D015815:Cell Adhesion Molecules