Suzushima H, Asou N, Hattori T, Takatsuki K
Second Department of Internal Medicine, Kumamoto University School of Medicine, Japan.
Leuk Lymphoma. 1994 Apr;13(3-4):257-62. doi: 10.3109/10428199409056289.
Adult T-cell leukemia (ATL) is a mature T-cell malignancy which is caused by human T lymphotropic virus type-I (HTLV-I). Most of the ATL cells are CD3+, CD4+, CD8-, and T-cell receptor (TCR) alpha beta+ and also express activated antigens such as HLA-DR and interleukin-2 receptor (IL2R) alpha chain (CD25). Diminished surface expression of the TCR alpha beta/CD3 complex is a specific feature of ATL cells. Since the gene transcript for each chain of this complex has been detected and surface expression of this complex is further decreased, accompanied by the induction of IL2R alpha chain, after stimulation with anti-CD3 monoclonal antibody (mAb), the TCR alpha beta/CD3 complex is considered to be down-modulated in vivo. We recently reported four ATL patients whose leukemic cells were CD4-, CD8- (double-negative; DN), TCR alpha beta+. These DN-ATL cells expressed S100 beta protein which was not detected in CD4+ ATL cells. Similar to CD4+ ATL cells, surface expression of the TCR alpha beta/CD3 complex on DN-ATL cells was decreased in vivo despite the lack of CD4 or CD8 as coreceptor. Therefore, the TCR alpha beta+ T-cell with or without CD4 is the sole target of HTLV-I induced leukemia and the down-modulation of the TCR alpha beta/CD3 complex is considered to play a key role in the development of ATL.
成人T细胞白血病（ATL）是一种由I型人类嗜T淋巴细胞病毒（HTLV-I）引起的成熟T细胞恶性肿瘤。大多数ATL细胞为CD3+、CD4+、CD8-，且T细胞受体（TCR）αβ+，还表达活化抗原，如HLA-DR和白细胞介素-2受体（IL2R）α链（CD25）。TCRαβ/CD3复合物的表面表达减少是ATL细胞的一个特异性特征。由于已检测到该复合物每条链的基因转录本，且在用抗CD3单克隆抗体（mAb）刺激后，该复合物的表面表达进一步降低，并伴有IL2Rα链的诱导，因此TCRαβ/CD3复合物被认为在体内发生了下调。我们最近报道了4例ATL患者，其白血病细胞为CD4-、CD8-（双阴性；DN）、TCRαβ+。这些DN-ATL细胞表达S100β蛋白，而在CD4+ ATL细胞中未检测到。与CD4+ ATL细胞相似，尽管缺乏作为共受体的CD4或CD8，但DN-ATL细胞上TCRαβ/CD3复合物的表面表达在体内仍降低。因此，有或无CD4的TCRαβ+ T细胞是HTLV-I诱导白血病的唯一靶标，TCRαβ/CD3复合物的下调被认为在ATL的发生发展中起关键作用。
