Leukocyte analysis from WHIM syndrome patients reveals a pivotal role for GRK3 in CXCR4 signaling

J Clin Invest. 2008 Mar;118(3):1074-84. doi: 10.1172/JCI33187.


Leukocytes from individuals with warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome, a rare immunodeficiency, and bearing a wild-type CXCR4 ORF (WHIM(WT)) display impaired CXCR4 internalization and desensitization upon exposure to CXCL12. The resulting enhanced CXCR4-dependent responses, including chemotaxis, probably impair leukocyte trafficking and account for the immunohematologic clinical manifestations of WHIM syndrome. We provided here evidence that GPCR kinase-3 (GRK3) specifically regulates CXCL12-promoted internalization and desensitization of CXCR4. GRK3-silenced control cells displayed altered CXCR4 attenuation and enhanced chemotaxis, as did WHIM(WT) cells. These findings identified GRK3 as a negative regulator of CXCL12-induced chemotaxis and as a candidate responsible for CXCR4 dysfunction in WHIM(WT) leukocytes. Consistent with this, we showed that GRK3 overexpression in both leukocytes and skin fibroblasts from 2 unrelated WHIM(WT) patients restored CXCL12-induced internalization and desensitization of CXCR4 and normalized chemotaxis. Moreover, we found in cells derived from one patient a profound and selective decrease in GRK3 products that probably resulted from defective mRNA synthesis. Taken together, these results have revealed a pivotal role for GRK3 in regulating CXCR4 attenuation and have provided a mechanistic link between the GRK3 pathway and the CXCR4-related WHIM(WT) disorder.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agammaglobulinemia / metabolism
  • Arrestins / physiology
  • Bacterial Infections / metabolism
  • Cell Movement
  • Chemokine CXCL12 / physiology
  • G-Protein-Coupled Receptor Kinase 3 / genetics
  • G-Protein-Coupled Receptor Kinase 3 / physiology*
  • Genetic Diseases, Inborn / blood*
  • Humans
  • Immunologic Deficiency Syndromes / metabolism*
  • Leukocytes / metabolism*
  • Neutropenia / metabolism
  • RNA, Messenger / analysis
  • Receptors, CXCR4 / physiology*
  • Signal Transduction / physiology*
  • Syndrome
  • Warts / metabolism
  • beta-Arrestins


  • Arrestins
  • CXCL12 protein, human
  • Chemokine CXCL12
  • RNA, Messenger
  • Receptors, CXCR4
  • beta-Arrestins
  • G-Protein-Coupled Receptor Kinase 3
  • GRK3 protein, human