Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité University Medicine Berlin, Campus Virchow Clinic, Berlin, Germany.
Transplantation. 2011 Dec 15;92(11):1269-77. doi: 10.1097/TP.0b013e318234e0e5.
BKV-associated nephropathy represents a serious complication of the posttransplant period in kidney transplant recipients. Monitoring BKV-specific immunity is of a special importance for estimation of clinical course in patients with BKV reactivation. Our recent data demonstrated that all five BKV antigens are immunogenic and elicit T-cell responses varying within patients. Therefore, all five BKV proteins should be evaluated for the assessment of BKV-specific immunity. However, analysis of five proteins performed separately is time- and cost-intensive and requires large amount of blood.
Using novel approach of a mixture of overlapping peptide pools encompassing all five BKV antigens (viral protein [VP] 1, VP2, VP3, large tumor antigen, and small tumor antigen) and multiparameter flow cytometry, we evaluate BKV-specific T cells in patients with a previous/present severe long-lasting or transient BKV reactivation. Patients without BKV reactivation were used as control.
In this study, we show that using mixture of overlapping peptide pool results in the magnitude of CD4- and CD8-positive BKV-specific T-cell response, which is significantly higher compared with any frequencies detected by previously used single BKV antigen stimulation. Of interest, patients with a history of rapid BKV clearance had significantly higher frequency of multifunctional interferon gamma-γ/interleukin (IL)-2/tumor necrosis factor-α and IL-2/tumor necrosis factor-α CD4-positive T cells, suggesting protective potential of polyfunctional T cells. Furthermore, we did not find IL-17-producing BKV-specific memory T cells in patients recovered from BKV reactivation.
Here, we established a fast and sensitive approach allowing the most comprehensive assessment of the total BKV immunity performed to date and offer a new platform for further prospective studies.
BK 病毒相关性肾病是肾移植受者移植后时期的严重并发症。监测 BK 病毒特异性免疫对于评估 BK 病毒再激活患者的临床病程具有特殊重要性。我们最近的数据表明，所有 5 种 BK 病毒抗原均具有免疫原性，并在患者体内引起不同的 T 细胞反应。因此，应评估所有 5 种 BK 病毒蛋白以评估 BK 病毒特异性免疫。然而，分别分析 5 种蛋白既费时又费成本，并且需要大量血液。
使用包含所有 5 种 BK 病毒抗原（病毒蛋白 [VP]1、VP2、VP3、大肿瘤抗原和小肿瘤抗原）的重叠肽池混合物的新方法和多参数流式细胞术，我们评估了有先前/现在严重持续或短暂 BK 病毒再激活病史的患者的 BK 病毒特异性 T 细胞。未发生 BK 病毒再激活的患者作为对照。
在这项研究中，我们表明，使用重叠肽池混合物可导致 CD4+和 CD8+BK 病毒特异性 T 细胞反应的幅度显著增加，与以前使用单一 BK 病毒抗原刺激检测到的任何频率相比，这种幅度明显更高。有趣的是，BK 病毒清除迅速的患者具有更高频率的多功能干扰素 γ-γ/白细胞介素（IL）-2/肿瘤坏死因子-α和 IL-2/肿瘤坏死因子-α CD4+T 细胞，表明多功能 T 细胞具有保护潜力。此外，我们在从 BK 病毒再激活中恢复的患者中未发现产生 IL-17 的 BK 病毒特异性记忆 T 细胞。
在这里，我们建立了一种快速、敏感的方法，可对迄今为止进行的最全面的总 BK 病毒免疫评估，并为进一步的前瞻性研究提供了新的平台。
