Larcher C, Fend F, Mitterer M, Prang N, Schwarzmann F, Huemer H P
Institute for Hygiene, University of Innsbruck, Austria.
Br J Haematol. 1995 Jul;90(3):532-40. doi: 10.1111/j.1365-2141.1995.tb05580.x.
The expression of EBV proteins and immunological properties were studied in the first stable cell line (SM) established from a patient presenting with persistent polyclonal B-cell lymphocytosis (PPBL). SM cells which represent a small population of EBV-positive atypical cells found in the peripheral blood of the patient express the KI-1 antigen (CD30) as well as the proto-oncogene bcl-2 product and cell surface markers of mature activated B lymphocytes. The cells harbour an EBV subtype A genome and contain EBNA2 protein. This argues against a transformation-incompetent virus as the main cause of the chronic active EBV infection observed in our patient. Latent membrane protein (LMP1) was weakly expressed and found predominantly in a perinuclear localization, a location which could lead to decreased immunogenicity in vivo. Similar to the EBV-transformed marmoset cell line B95-8, SM cells were in part productively infected as transcription of the immediate early gene BZLF1 could be shown and in some cells high levels of EBV-genome were detected by in situ hybridization with a BamH1 W-probe. Comparable to the atypical cells in the peripheral blood of the patient. EBV small RNAs were not detected with EBER-specific probes. Of interest, we noticed a markedly increased production of soluble CD21 (sCD21) antigen by SM cells as compared to LCL-type Burkitt's lymphoma cell lines. This could explain the elevated sCD21 levels observed in the serum of our PPBL patient and confirms our previous findings in patients with acute EBV infection. It also suggests a possible role of sCD21 in EBV-mediated regulation of the immune response and provides a possible explanation for the dysregulation of the humoral immune system observed in PPBl patients.
在从一名患有持续性多克隆B细胞淋巴细胞增多症（PPBL）的患者建立的首个稳定细胞系（SM）中，对EBV蛋白的表达和免疫特性进行了研究。SM细胞代表了在患者外周血中发现的一小部分EBV阳性非典型细胞，表达KI-1抗原（CD30）以及原癌基因bcl-2产物和成熟活化B淋巴细胞的细胞表面标志物。这些细胞含有EBV A亚型基因组并含有EBNA2蛋白。这表明在我们的患者中观察到的慢性活动性EBV感染的主要原因不是无转化能力的病毒。潜伏膜蛋白（LMP1）表达较弱，主要定位于核周，这种定位可能导致体内免疫原性降低。与EBV转化的狨猴细胞系B95-8相似，SM细胞部分被有效感染，因为可以显示立即早期基因BZLF1的转录，并且在一些细胞中通过用BamH1 W探针进行原位杂交检测到高水平的EBV基因组。与患者外周血中的非典型细胞类似，用EBER特异性探针未检测到EBV小RNA。有趣的是，我们注意到与LCL型伯基特淋巴瘤细胞系相比，SM细胞产生的可溶性CD21（sCD21）抗原明显增加。这可以解释在我们的PPBL患者血清中观察到的sCD21水平升高，并证实了我们先前在急性EBV感染患者中的发现。这也表明sCD21在EBV介导的免疫反应调节中可能起作用，并为在PPBl患者中观察到的体液免疫系统失调提供了一种可能的解释。
