Department of Immunology, School of Public Health, Tehran University of Medical Sciences, 14155, Tehran, Iran.
Cytotechnology. 2014 Jan;66(1):95-105. doi: 10.1007/s10616-013-9542-x. Epub 2013 Feb 13.
Infection of human B cells with Epstein-Barr virus (EBV) induces polyclonal activation in almost all infected cells, but a small proportion of infected cells are transformed to immortalized lymphoblastoid cell lines. Since B cells are activated also by CD40 ligand (CD40L) and Toll-like receptor (TLR) agonists via a similar signaling pathway, it is likely that costimulation through these molecules could result in synergistic enhancement of the transformation efficiency of EBV. In this study, the stimulatory effect of TLR7/8 (R848), TLR9 (CpG) agonists and/or CD40L on transformation efficiency of EBV in normal human B cells was assessed using the limiting dilution assay. Costimulation of peripheral blood mononuclear cells (PBMCs) with CpG and R848, but not CD40L, increased significantly the frequency of EBV transformed B cells (p < 0.001). Neither synergistic nor additive effects were observed between TLR agonists and CD40L and also TLR7/8 and TLR9 agonists. Costimulation with R848, CpG and CD40L enhanced the proliferative response of B cells infected with EBV. This effect was more evident when enriched B cells were employed, compared to PBMCs. The promoting effect of TLR agonists stimulation, implies that EBV may take advantage of the genes induced by the TLR stimulation pathway for viral latency and oncogenesis.
人 B 细胞感染 EBV 后，几乎所有受感染的细胞都会被诱导发生多克隆激活，但只有一小部分被感染的细胞会转化为永生化淋巴母细胞系。由于 B 细胞也可通过 CD40 配体（CD40L）和 Toll 样受体（TLR）激动剂通过相似的信号通路被激活，因此这些分子的共刺激很可能导致 EBV 转化效率的协同增强。在这项研究中，通过有限稀释分析评估了 TLR7/8（R848）、TLR9（CpG）激动剂和/或 CD40L 对正常人 B 细胞中 EBV 转化效率的刺激作用。CpG 和 R848 共刺激外周血单核细胞（PBMCs）可显著增加 EBV 转化 B 细胞的频率（p<0.001）。TLR 激动剂与 CD40L 之间没有观察到协同或相加作用，TLR7/8 和 TLR9 激动剂之间也没有观察到协同或相加作用。R848、CpG 和 CD40L 的共刺激增强了感染 EBV 的 B 细胞的增殖反应。与 PBMCs 相比，用富集的 B 细胞进行共刺激时，这种效果更为明显。TLR 激动剂刺激的促进作用意味着 EBV 可能会利用 TLR 刺激途径诱导的基因来实现病毒潜伏和致癌。
