Walker Sonya R, Ogagan P Dafé, DeAlmeida Dilhari, Aboka Alexander M, Barksdale Edward M
Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
J Pediatr Surg. 2006 Jan;41(1):260-5. doi: 10.1016/j.jpedsurg.2005.10.073.
BACKGROUND/PURPOSE: Chemokine receptor (CCR7 [cysteine chemokine receptor 7]) and ligand (CCL19) interactions trigger dendritic cell (DC) recruitment from sites of antigen uptake to secondary lymphoid organs for T-cell priming and tumor lysis. Inhibition of this interaction may allow some aggressive tumors to evade immune detection. Although we have shown dysfunctional DC migration in murine neuroblastoma (NB) in vivo, the molecular mechanisms of impairment are unknown. We hypothesize that NB-induced aberrant CCR7-CCL19 signaling impairs DC migration.
Bone marrow-derived DCs were isolated from A/J mice (n = 24), matured, and cocultured with murine NB (TBJ) or media (control) for 7 days. CCR7 and CCL19 protein and RNA expressions by control and NB-exposed DC were measured by flow cytometry, Western blot analysis, and polymerase chain reaction. Migration assays using Transwell plates (Corning Incorporated, Corning, NY, via Fisher Scientific, Pittsburgh, Pa) were performed with matured DC and CCL19. Furthermore, to determine if these changes in DC migration could be overcome, superphysiological concentrations of CCL19 (100 ng/mL) were used. Results are reported as the average percentage +/- SD.
No significant differences in CCR7 or CCL19 protein expression between tumor and control were seen at 7 days. However, NB significantly decreased CCL19-induced migration by more than 50%: control (26.48% +/- 1.52%) vs DC cocultured with TBJ (12.7% +/- 0.3%) (P < .05). Superphysiological doses up to 100 ng/mL CCL19 showed no significant upregulation in migration in DC cocultured with tumor cells.
Although in vitro coculture with NB does not induce significant changes in either CCR7 or CCL19 expression, profound functional impairments in CCR7/CCL19-mediated migration occurs. These findings suggest that intracellular signal transduction pathways for these chemokines may be impaired by tumor. Targeting this chemokine-receptor pathway may provide a novel therapeutic strategy.
背景/目的：趋化因子受体（CCR7 [半胱氨酸趋化因子受体7]）与配体（CCL19）的相互作用可触发树突状细胞（DC）从抗原摄取部位募集至二级淋巴器官，以启动T细胞并进行肿瘤溶解。抑制这种相互作用可能会使一些侵袭性肿瘤逃避免疫检测。尽管我们已在体内小鼠神经母细胞瘤（NB）中证明DC迁移功能失调，但其受损的分子机制尚不清楚。我们推测NB诱导的异常CCR7 - CCL19信号传导会损害DC迁移。
从A/J小鼠（n = 24）中分离出骨髓来源的DC，使其成熟，并与小鼠NB（TBJ）或培养基（对照）共培养7天。通过流式细胞术、蛋白质印迹分析和聚合酶链反应测量对照DC和暴露于NB的DC中CCR7和CCL19的蛋白质及RNA表达。使用Transwell板（康宁公司，纽约州康宁，经由宾夕法尼亚州匹兹堡的赛默飞世尔科技公司提供）对成熟DC和CCL19进行迁移试验。此外，为了确定是否可以克服DC迁移中的这些变化，使用了超生理浓度的CCL19（100 ng/mL）。结果以平均百分比±标准差表示。
7天时，肿瘤组和对照组之间CCR7或CCL19的蛋白质表达无显著差异。然而，NB使CCL19诱导的迁移显著降低了50%以上：对照组（26.48%±1.52%）与与TBJ共培养的DC组（12.7%±0.3%）相比（P <.05）。高达100 ng/mL的超生理剂量CCL19在与肿瘤细胞共培养的DC中未显示出迁移的显著上调。
尽管与NB进行体外共培养不会诱导CCR7或CCL19表达发生显著变化，但CCR7/CCL19介导的迁移会出现严重的功能障碍。这些发现表明，这些趋化因子的细胞内信号转导途径可能会受到肿瘤的损害。靶向这种趋化因子 - 受体途径可能会提供一种新的治疗策略。
