Calcium signaling capacity of the CD11b/CD18 integrin on human neutrophils

Exp Cell Res. 1991 Aug;195(2):504-8. doi: 10.1016/0014-4827(91)90402-g.

Abstract

The CD11b/CD18 integrin is a major cell adhesion molecule of myelomonocytic cells. Exposure of human neutrophils in suspension to CD11b or CD18 monoclonal antibodies (mAbs)2 does not affect the resting level of cytosolic free Ca2+ in these cells; however, a subsequent cross-linking of either of these antibodies triggers a prompt and significant cytosolic-free Ca2+ transient lasting about 10 min. The rise in cytosolic-free Ca2+ (from 130 +/- 2 to 414 +/- 12 nM or 111 +/- 12 to 331 +/- 22 nM caused by cross-linking of CD11b or CD18 subunits, respectively) is due to both mobilization of Ca2+ from intracellular stores and influx of Ca2+ across the plasma membrane. Cross-linking of the common leukocyte antigen (CD45) did not alter the basal level of cytosolic free Ca2+. In accordance with other adherence-induced phenomena and with CD11/CD18-mediated phagocytosis, these Ca2+ signals were only modestly affected by pertussis toxin. Thus, the present data clearly indicate that the CD11b/CD18 integrin on human neutrophils is capable of inducing a prompt cytosolic-free Ca2+ signal. These findings directly support the recent suggestion that the CD11b/CD18 integrin is responsible for the "spontaneous oscillations" of cytosolic-free Ca2+ observed in adherent neutrophils and, at least partially, also explain how integrin-mediated adherence can modify the functional responsiveness of neutrophils to a subsequent agonist stimulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD / metabolism*
  • CD11 Antigens
  • CD18 Antigens
  • Calcium / metabolism*
  • Cell Adhesion
  • Cross-Linking Reagents
  • Cytosol / metabolism
  • Humans
  • Neutrophils / drug effects
  • Neutrophils / immunology
  • Neutrophils / metabolism*
  • Pertussis Toxin
  • Signal Transduction* / drug effects
  • Virulence Factors, Bordetella / pharmacology

Substances

  • Antigens, CD
  • CD11 Antigens
  • CD18 Antigens
  • Cross-Linking Reagents
  • Virulence Factors, Bordetella
  • Pertussis Toxin
  • Calcium