Phagocyte cell migration is mediated by phospholipases PLD1 and PLD2

Blood. 2006 Nov 15;108(10):3564-72. doi: 10.1182/blood-2006-02-005959. Epub 2006 Jul 27.

Abstract

We have investigated whether the signaling protein phospholipase D is implicated in leukocyte cell motility. Treating differentiated HL-60 cells with small interfering RNAs (siRNAs), to deplete endogenous expression of the PLD1 isoform, led to an abolishment of basal chemokinesis that could not be rescued with chemoattractants ENA-78, FMLP, and IL-8. Transient overexpression of PLD1 increased both chemokinesis and chemotaxis toward IL-8 and FMLP but not toward ENA-78. Chemokinesis was not mediated by the enzymatic activity of PLD1, but the chemotactic response was, because a lipase-inactive mutant (PLD1-K830R) negated all chemokine-induced potentiating actions and because IL-8 and FMLP increased activity in vitro. Gene expression silencing of the other mammalian isoform, PLD2, also led to cell migration arrest, whereas ENA-78 selectively increased endogenous PLD2 activity and chemotaxis of HL-60 cells overexpressing a myc-pcDNA-PLD2 construct. Thus, PLD1 is differentially activated by CXCR-1, whereas CXCR-2 (and possibly CXCR-1) mediates PLD2 activation. Finally, immunofluorescence microscopy showed that both isoforms were associated with cell polarity and directionality concomitantly with adhesion and F-actin polymerization in response to IL-8. These data represent the first demonstration of the involvement of PLD and its enzymatic activity toward chemokines in the key physiologic process of leukocyte migration.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Cell Adhesion
  • Cell Movement / drug effects
  • Cell Polarity
  • Chemotaxis, Leukocyte* / drug effects
  • HL-60 Cells
  • Humans
  • Interleukin-8 / pharmacology
  • N-Formylmethionine Leucyl-Phenylalanine / pharmacology
  • Neutrophils / physiology
  • Phagocytes / physiology*
  • Phospholipase D / physiology*
  • RNA, Small Interfering / pharmacology
  • Receptors, Interleukin-8A / physiology
  • Receptors, Interleukin-8B / physiology

Substances

  • Interleukin-8
  • RNA, Small Interfering
  • Receptors, Interleukin-8A
  • Receptors, Interleukin-8B
  • N-Formylmethionine Leucyl-Phenylalanine
  • phospholipase D2
  • Phospholipase D
  • phospholipase D1