Migration of a human keratinocyte cell line (HACAT) to interstitial collagen type I is mediated by the alpha 2 beta 1-integrin receptor.
The migratory response of the human keratinocyte cell line HaCaT to collagen type I and the molecular mechanism underlying collagen-mediated migration have been analyzed. The migratory response of HaCaT cells to collagen type I consisted of a dose-dependent migration to insoluble step gradients of substratum-bound collagen (haptotaxis) and to gradients of soluble collagen (chemotaxis). Checkerboard analysis demonstrated a minor chemokinetic component. Denatured collagen type I was less chemoattractive than the native triple-helical form. Pre-treatment of cells with 25-250 micrograms/ml of synthetic peptides containing the fibronectin cell-recognition sequence RGD (Arg-Gly-Asp) resulted in a concentration-dependent inhibition of fibronectin-mediated chemotaxis, whereas chemotaxis to collagen was not affected. We then investigated the role of VLA/collagen-receptors for collagen type I-induced chemotaxis. Monoclonal antibody (MoAb) 5E8, which selectively blocks function of the alpha 2 subunit of the VLA-2/collagen receptor, dose-dependently inhibited the chemotactic response of HaCaT cells to collagen. This effect was specific for collagen-mediated chemotaxis because the chemotactic response to fibronectin remained unaffected. In contrast, a function blocking MoAb directed to the alpha 3 subunit of the coexpressed VLA-3 receptor, which is also capable of binding collagen, had no effect. However, function blocking MoAb directed to the beta 1-chain of integrins completely inhibited chemotaxis to collagen type I. Based on our results, we propose that the chemotactic migration of the human keratinocyte cell line (HaCaT) to collagen type I is specifically mediated by the RGD independent VLA-2/collagen receptor (alpha 2 beta 1) of the integrin family.
Scharffetter-Kochanek
K
K
Department of Dermatology, Universities of Düsseldorf, F.R.G.
Klein
C E
CE
Heinen
G
G
Mauch
C
C
Schaefer
T
T
Adelmann-Grill
B C
BC
Goerz
G
G
Fusenig
N E
NE
Krieg
T M
TM
Plewig
G
G
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology; D002460:Cell Line; D002465:Cell Movement; D002633:Chemotaxis; D003094:Collagen / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000502:physiology*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000494:pharmacology; D016029:Receptors, Very Late Antigen / Q000276:immunology / Q000502:physiology*
D000911:Antibodies, Monoclonal; D009842:Oligopeptides; D016029:Receptors, Very Late Antigen; C047981:arginyl-glycyl-aspartic acid; D003094:Collagen