Department of Pediatric Hematology/Oncology, University Children's Hospital, Eberhard Karl's University, Tuebingen, Germany.
Haematologica. 2010 Aug;95(8):1381-8. doi: 10.3324/haematol.2009.021121. Epub 2010 Feb 9.
Natural killer cells have been demonstrated to exert remarkable graft-versus-leukemia effects after haploidentical transplantation. Acquisition of both, inhibiting and activating, receptors on developing natural killer cells is an important step in their functional maturation. Here, we report on the reconstitution of natural killer receptors after haploidentical transplantation of T-and B-cell (CD3/CD19) depleted grafts with co-transfusion of natural killer cells in children and its influence on natural killer cell activity and clinical outcome.
We analyzed reconstitution patterns of natural killer receptors at different time intervals after haploidentical transplantation by multi-color flow cytometry. Natural killer cell activity and antibody-dependent cellular cytotoxicity was tested against cell lines and leukemic blasts in vitro. Survival was analyzed using Kaplan-Meier estimates.
Recovery of CD56(+)/CD16(+) cells was fast with high cytolytic activity against K562 and strong antibody-dependent cellular cytotoxicity activity against neuroblastoma and leukemic blasts as early as day 14 posttransplant. KIR reconstitution showed a predominance of KIR negative natural killer cells early after transplantation and an early reconstitution of CD158b compared to CD158a and CD158e. These differences were independent of presence or absence of the corresponding KIR ligands in donors or recipients. This reconstitution pattern was associated with a higher relapse probability of patients homozygous for HLA-C1-alleles compared to patients homozygous or even heterozygous for HLA-C2-alleles.
Our results indicate a fast recovery of functional and alloreactive natural killer cells with a constant KIR pattern after haploidentical transplantation with T- and B-cell depleted grafts. Moreover, these natural killer cells can mediate antibody-dependent cellular cytotoxicity and therefore may allow for an early use of antibodies against residual malignant cells.
自然杀伤细胞在单倍体相合移植后显示出显著的移植物抗白血病效应。在自然杀伤细胞的功能成熟过程中，获得抑制性和激活性受体是一个重要步骤。在这里，我们报告了在 T 和 B 细胞（CD3/CD19）耗竭的移植物输注自然杀伤细胞后，单倍体相合移植后自然杀伤细胞受体的重建及其对自然杀伤细胞活性和临床结果的影响。
我们通过多色流式细胞术分析了单倍体相合移植后不同时间间隔自然杀伤细胞受体的重建模式。在体外，用细胞系和白血病细胞检测自然杀伤细胞活性和抗体依赖性细胞毒性。采用 Kaplan-Meier 估计法分析生存情况。
CD56(+)/CD16(+)细胞的恢复很快，对 K562 的细胞毒性活性很高，对神经母细胞瘤和白血病细胞的抗体依赖性细胞毒性活性很强，早在移植后第 14 天就出现了这种情况。KIR 重建显示，早期移植后 KIR 阴性自然杀伤细胞占优势，与 CD158a 和 CD158e 相比，CD158b 早期重建。这些差异与供体或受体中是否存在相应的 KIR 配体无关。这种重建模式与 HLA-C1 等位基因纯合子患者的复发概率较高相关，而与 HLA-C2 等位基因纯合子或杂合子患者的复发概率较高相关。
我们的结果表明，在 T 和 B 细胞耗竭的移植物输注后，单倍体相合移植后，具有恒定 KIR 模式的功能性和同种异体反应性自然杀伤细胞快速恢复。此外，这些自然杀伤细胞可以介导抗体依赖性细胞毒性，因此可以早期使用针对残留恶性细胞的抗体。
