ICAM-1-independent adhesion of neutrophils to phorbol ester-stimulated human airway epithelial cells.
Intercellular adhesion molecule-1 (ICAM-1) is the only inducible adhesion receptor for neutrophils identified in bronchial epithelial cells. We stimulated human airway epithelial cells with various agonists to evaluate whether ICAM-1-independent adhesion mechanisms could be elicited. Phorbol 12-myristate 13-acetate (PMA) stimulation of cells of the alveolar cell line A549 caused a rapid, significant increase in neutrophil adhesion from 11 +/- 3 to 49 +/- 7% (SE). A significant increase from 17 +/- 4 to 39 +/- 6% was also observed for neutrophil adhesion to PMA-stimulated human bronchial epithelial cells in primary culture. Although ICAM-1 expression was upregulated by PMA at late time points, it was not affected at 10 min when neutrophil adhesion was already clearly enhanced. Antibodies to ICAM-1 had no effect on neutrophil adhesion. In contrast, antibodies to the leukocyte integrin beta-chain CD18 totally inhibited the adhesion of neutrophils to PMA-stimulated epithelial cells. These results demonstrate that PMA stimulation of human airway epithelial cells causes an increase in neutrophil adhesion that is not dependent on ICAM-1 upregulation.
Celi
A
A
Laboratorio di Biologia Cellulare, Fisiopatologia Respiratoria, Dipartimento Cardiotoracico dell'Università di Pisa, 56124 Pisa, Italy. aceli@dcap.med.unipi.it
Cianchetti
S
S
Petruzzelli
S
S
Carnevali
S
S
Baliva
F
F
Giuntini
C
C
D001980:Bronchi / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000502:physiology*; D007477:Ions; D008670:Metals / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011650:Pulmonary Alveoli / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D015815:Cell Adhesion Molecules; D007477:Ions; D008670:Metals; D011500:Protein Synthesis Inhibitors; D018799:Intercellular Adhesion Molecule-1; D013755:Tetradecanoylphorbol Acetate