A comparison of post-receptor signal transduction events in Jurkat cells transfected with either IL-8R1 or IL-8R2. Chemokine mediated activation of p42/p44 MAP-kinase (ERK-2)

FEBS Lett. 1995 May 8;364(2):211-4. doi: 10.1016/0014-5793(95)00397-r.

Abstract

The CXC chemokine, IL-8, is a potent chemoattractant of neutrophils and binds to two distinct receptors, termed IL-8R1 and IL-8R2. These receptors share high affinity for IL-8, however, only IL-8R1 is specific for IL-8 whereas IL-8R2 binds other related chemokines, including GRO alpha with high affinity. Stable Jurkat transfectants were generated expressing either functional IL-8R1 or IL-8R2 (J-IL8R1 and J-IL8R2). Both J-IL8R1 and J-IL8R2 exhibited high affinity IL-8 binding (Kd 3-5 nM) with respective receptor densities of 23,000 +/- 3,000 and 18,500 +/- 1,500. Pre-treatment of both transfectants with 1.0 micrograms/ml B. pertussis toxin (PTx) resulted in inhibition of IL-8 mediated intracellular Ca2+ mobilisation and chemotaxis, without altering the receptor's affinity for its ligand. This indicates that both receptors couple to a PTx-sensitive G-protein. Further studies showed that IL-8R1 and IL-8R2 could mediate time-dependent phosphorylation of p42/p44 MAP-kinase. In both transfectants, phosphorylation was maximal at 1-2 min after IL-8 stimulation and could be inhibited by PTx. Stimulation of J-IL8R1 and J-IL8R2 with GRO alpha revealed that this chemokine was a more potent activator of MAP-kinase in J-IL8R2, an observation reflected in the high affinity binding of GRO alpha to IL-8R2. These studies indicate that chemokines are capable of activating protein kinases and with regards to PTx-sensitivity and MAP-kinase stimulation, no significant differences between IL-8R1 and IL-8R2 post-receptor signalling occur during cell activation by IL-8.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Enzyme Activation / drug effects
  • GTP-Binding Proteins / metabolism
  • Humans
  • Interleukin-8 / pharmacology
  • Mitogen-Activated Protein Kinase 1
  • Pertussis Toxin
  • Protein-Serine-Threonine Kinases / metabolism*
  • Protein-Tyrosine Kinases / metabolism*
  • Receptors, Interleukin / genetics
  • Receptors, Interleukin / metabolism*
  • Receptors, Interleukin-8A
  • Signal Transduction
  • Transfection
  • Virulence Factors, Bordetella / pharmacology

Substances

  • Interleukin-8
  • Receptors, Interleukin
  • Receptors, Interleukin-8A
  • Virulence Factors, Bordetella
  • Pertussis Toxin
  • Protein-Tyrosine Kinases
  • Protein-Serine-Threonine Kinases
  • Mitogen-Activated Protein Kinase 1
  • GTP-Binding Proteins