Casale T B, Carolan E J
Nebraska Medical Research Institute, Papillion 68046-4796, USA.
Inflamm Res. 1999 Jan;48(1):22-7. doi: 10.1007/s000110050379.
To better understand the mechanisms by which cytokines induced neutrophils to migrate into the airways, we constructed a novel in vitro model system.
Human umbilical vein endothelial cell (HUVE) monolayers were grown on top of permeable filters and human lung type II-like alveolar epithelial cell (A549) monolayers were grown on the undersurface of the filters.
The sequential migration of human neutrophils through the endothelium (apical to basal movement) and subsequently through the epithelium (basal to apical movement) in response to IL-1 beta or TNF alpha located basally to the epithelium was measured.
We found that IL-1 beta and TNF alpha induced dose-responsive and time-dependent migration through the double monolayers-filter complex. The pattern of migration was similar, and the amount greater than or equal to that observed through either single monolayer/filter complex. Neutrophil migration through naked filters was generally less than that observed through the cellular barriers. The contribution of the monolayer orientation was also examined and found to favor the more physiologic directional migration of neutrophils through an endothelial and epithelial barrier, apical to basal and basal to apical, respectively. In contrast, FMLP-induced neutrophil migration was not dependent upon either the orientation or presence of the monolayer(s).
Thus, we have established an in vitro model system to examine cytokine-induced sequential migration of neutrophils through endothelium and the respiratory epithelium in a manner analogous to that occurring with an in vivo airway stimulus causing neutrophil-rich airway inflammatory responses.
为了更好地理解细胞因子诱导中性粒细胞迁移至气道的机制，我们构建了一种新型的体外模型系统。
人脐静脉内皮细胞（HUVE）单层生长在可渗透滤器的顶部，人肺II型样肺泡上皮细胞（A549）单层生长在滤器的下表面。
测量人中性粒细胞响应位于上皮细胞下方的白细胞介素-1β（IL-1β）或肿瘤坏死因子-α（TNF-α），先后通过内皮细胞（从顶端到基底移动）以及随后通过上皮细胞（从基底到顶端移动）的迁移情况。
我们发现IL-1β和TNF-α诱导中性粒细胞通过双层单层-滤器复合物进行剂量反应性和时间依赖性迁移。迁移模式相似，且迁移量大于或等于通过任何一种单层/滤器复合物所观察到的量。中性粒细胞通过裸露滤器的迁移通常少于通过细胞屏障所观察到的迁移。我们还研究了单层方向的影响，发现其有利于中性粒细胞分别通过内皮和上皮屏障进行更符合生理的定向迁移，即从顶端到基底以及从基底到顶端。相比之下，N-甲酰甲硫氨酰-亮氨酰-苯丙氨酸（FMLP）诱导的中性粒细胞迁移既不依赖于单层的方向，也不依赖于单层的存在。
因此，我们建立了一种体外模型系统，以类似于体内气道刺激引起富含中性粒细胞的气道炎症反应的方式，研究细胞因子诱导的中性粒细胞通过内皮和呼吸道上皮的顺序迁移。
