Celi A, Cianchetti S, Petruzzelli S, Carnevali S, Baliva F, Giuntini C
Laboratorio di Biologia Cellulare, Fisiopatologia Respiratoria, Dipartimento Cardiotoracico dell'Università di Pisa, 56124 Pisa, Italy.
Am J Physiol. 1999 Sep;277(3):L465-71. doi: 10.1152/ajplung.1999.277.3.L465.
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.
细胞间黏附分子-1（ICAM-1）是在支气管上皮细胞中鉴定出的唯一可诱导的中性粒细胞黏附受体。我们用各种激动剂刺激人气道上皮细胞，以评估是否能引发不依赖ICAM-1的黏附机制。用佛波酯12-肉豆蔻酸酯13-乙酸酯（PMA）刺激肺泡细胞系A549的细胞，导致中性粒细胞黏附迅速显著增加，从11±3%增至49±7%（标准误）。对于原代培养中PMA刺激的人支气管上皮细胞，中性粒细胞黏附也从17±4%显著增加到39±6%。虽然在后期时间点PMA上调了ICAM-1的表达，但在10分钟时当中性粒细胞黏附已经明显增强时，ICAM-1表达并未受到影响。抗ICAM-1抗体对中性粒细胞黏附没有影响。相反，抗白细胞整合素β链CD18抗体完全抑制了中性粒细胞对PMA刺激的上皮细胞的黏附。这些结果表明，PMA刺激人气道上皮细胞会导致中性粒细胞黏附增加，且这种增加不依赖于ICAM-1的上调。
