Ichikawa Ayako, Miyoshi Hiroaki, Arakawa Fumiko, Kiyasu Junichi, Sato Kensaku, Niino Daisuke, Kimura Yoshizo, Yoshida Maki, Kawano Riko, Muta Hiroko, Sugita Yasuo, Ohshima Koichi
Department of Pathology, School of Medicine, Kurume University, Kurume, Fukuoka 830 0011, Japan.
Biostatistics Center, School of Medicine, Kurume University, Kurume, Fukuoka 830 0011, Japan.
Oncol Lett. 2017 Jun;13(6):4611-4618. doi: 10.3892/ol.2017.6067. Epub 2017 Apr 21.
Human T-cell lymphotropic virus type (HTLV)-1 Tax is a viral protein that has been reported to be important in the proliferation of adult T-cell leukemia/lymphoma (ATLL) cells and to be a target of HTLV-1-specific cytotoxic T lymphocytes (CTLs). However, it is not clear how Tax-specific CTLs behave in lymph nodes of ATLL patients. The present study analyzed the immunostaining of Tax-specific CTLs. Furthermore, ATLL tumor cells are known to be positive for forkhead box P3 (Foxp3)and to have a regulatory T (Treg)-cell-like function. The association between T-reg function and number and activity of Tax-specific CTLs was also investigated. A total of 15 ATLL lymphoma cases with human leukocyte antigen (HLA)-A24, for which Tax has a high affinity, were selected from the files of the Department of Pathology, School of Medicine, Kurume University (Kurume, Japan) using a polymerase chain reaction (PCR) method. Immunostaining was performed for cluster of differentiation (CD) 20, CD3, CD4, CD8, T-cell intracellular antigen-1 and Foxp3 in paraffin sections, and for Tax, interferon γ and HLA-A24 in frozen sections. In addition, the staining of Tax-specific CTLs (HLA-A24-restricted) was analyzed by MHC Dextramer assay in frozen sections. In addition, the messenger RNA expression of Tax and HTLV-1 basic leucine zipper factor were also evaluated by reverse transcription-PCR. Immunohistochemical staining of Tax protein in lymphoma tissue revealed the presence of positive lymphoma cells ranging from 5 to 80%, and immunohistochemical staining of HLA-A24 revealed the presence of positive lymphoma cells ranging from 1 to 95%. The expression of Tax and HLA-A24 was downregulated by viral function. Foxp3, a marker for Treg cells, was expressed in 0-90% of cells. Several cases exhibited Tax-specific CTL (HLA-A24-restricted)-positive cells, and there was an inverse correlation between Tax-specific CTLs and Foxp3. However, neither Tax nor HLA-A24 expression was associated with CTL or Foxp3. Our study indicated the possibility that ATLL cells, which expressed Tax, target of CTL, evade the CTL-mediated immune control by expression of Foxp3 as a Treg function.
人类嗜T细胞病毒1型（HTLV-1）Tax蛋白是一种病毒蛋白，据报道其在成人T细胞白血病/淋巴瘤（ATLL）细胞增殖中起重要作用，并且是HTLV-1特异性细胞毒性T淋巴细胞（CTL）的作用靶点。然而，尚不清楚Tax特异性CTL在ATLL患者淋巴结中的行为表现。本研究分析了Tax特异性CTL的免疫染色情况。此外，已知ATLL肿瘤细胞叉头框P3（Foxp3）呈阳性，并具有调节性T（Treg）细胞样功能。同时还研究了Treg功能与Tax特异性CTL数量及活性之间的关联。使用聚合酶链反应（PCR）方法，从久留米大学医学院病理学系（日本久留米）的档案中选取了15例携带人类白细胞抗原（HLA）-A24且Tax与之具有高亲和力的ATLL淋巴瘤病例。对石蜡切片中的分化簇（CD）20、CD3、CD4、CD8、T细胞内抗原-1和Foxp3进行免疫染色，对冰冻切片中的Tax、干扰素γ和HLA-A24进行免疫染色。此外，通过MHC Dextramer检测法对冰冻切片中Tax特异性CTL（HLA-A24限制性）的染色情况进行分析。另外，还通过逆转录PCR评估Tax和HTLV-1碱性亮氨酸拉链因子的信使RNA表达。淋巴瘤组织中Tax蛋白的免疫组织化学染色显示，阳性淋巴瘤细胞的比例为5%至80%，HLA-A24的免疫组织化学染色显示，阳性淋巴瘤细胞的比例为1%至95%。Tax和HLA-A24的表达因病毒功能而下调。Treg细胞标志物Foxp3在0%至90%的细胞中表达。部分病例出现Tax特异性CTL（HLA-A24限制性）阳性细胞，且Tax特异性CTL与Foxp3之间呈负相关。然而，Tax和HLA-A24的表达均与CTL或Foxp3无关。我们的研究表明，表达Tax（CTL的作用靶点）的ATLL细胞有可能通过表达作为Treg功能的Foxp3来逃避CTL介导的免疫控制。
