Pham Betty, Piard-Ruster Karine, Silva Richard, Gallo Amy, Esquivel Carlos O, Martinez Olivia M, Krams Sheri M
Division of Abdominal Transplantation, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5492, USA.
Pediatr Transplant. 2012 Mar;16(2):176-82. doi: 10.1111/j.1399-3046.2012.01653.x.
NK cells are important in the immune response against tumors and virally infected cells. A balance between inhibitory and activating receptors controls the effector functions of NK cells. We examined the fate of circulating NK cells and the expression of the NK cell-activating receptors in pediatric liver transplant recipients. Blood specimens were collected from 38 pediatric liver transplant recipients before transplant, and at one wk, one, three, six, and nine months, and one yr post-transplant. PBMCs were isolated and analyzed for the levels of NK cell activation receptors NKp30, NKp46, and NKG2D in the CD56(dim) CD16(+) and CD56(bright) CD16(+/-) subsets of NK cells. We demonstrated that there is a significant decrease in the percentage of circulating NK cells post-transplant (pretransplant 7.69 ± 1.54 vs. one wk post-transplant 1.73 ± 0.44) in pediatric liver transplant recipients. Interestingly, NKp30 expression is significantly increased, while NKp46 and NKG2D levels remain stable on the NK cells that persist at one wk post-transplant. These data indicate that the numbers and subsets of circulating NK cells are altered in children after liver transplantation.
自然杀伤（NK）细胞在针对肿瘤和病毒感染细胞的免疫反应中发挥着重要作用。抑制性受体和激活受体之间的平衡控制着NK细胞的效应功能。我们研究了小儿肝移植受者循环NK细胞的命运以及NK细胞激活受体的表达情况。在移植前、移植后1周、1个月、3个月、6个月、9个月及1年时，采集了38例小儿肝移植受者的血液样本。分离外周血单个核细胞（PBMC），并分析NK细胞CD56（dim）CD16（+）和CD56（bright）CD16（+/-）亚群中NK细胞激活受体NKp30、NKp46和NKG2D的水平。我们发现，小儿肝移植受者移植后循环NK细胞百分比显著下降（移植前7.69±1.54 vs.移植后1周1.73±0.44）。有趣的是，在移植后1周仍存在的NK细胞上，NKp30表达显著增加，而NKp46和NKG2D水平保持稳定。这些数据表明，肝移植后儿童循环NK细胞的数量和亚群发生了改变。
