Identification of new epitopes recognized by human monoclonal antibodies with neutralizing and antibody-dependent cellular cytotoxicity activities specific for human T cell leukemia virus type 1.
Identification of new epitopes recognized by human monoclonal antibodies with neutralizing and antibody-dependent cellular cytotoxicity activities specific for human T cell leukemia virus type 1.
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鉴定人单克隆抗体识别的新表位，具有针对人 T 细胞白血病病毒 1 型的中和和抗体依赖性细胞毒性活性。
作者：
M. Kuroki;Masafumi Nakamura;Y. Itoyama;Y. Tanaka;H. Shiraki;Eishi Baba;T. Esaki;T. Tatsumoto;S. Nagafuchi;Shuji Nakano
我们已经从HTLV-1相关脊髓病/热带痉挛性下肢轻瘫患者的外周血B淋巴细胞中产生了许多EBV转化的B细胞系，其产生抗人T细胞白血病病毒1型（HTLV-1）的人mAb。将对应于HTLV-1 gag和env蛋白的抗原区域的各种合成肽用于ELISA中抗体的筛选。在我们的研究中，对gag p19氨基酸100至130的4种IgG mAb和env p46氨基酸175至199的5种IgG mAb进行了表征。免疫荧光实验表明，所有这些单克隆抗体特异性结合HTLV-1-轴承细胞系的表面。在这些mAb中，一种抗gp 46 mAb，命名为KE 36 -11，中和HTLV-1的感染性，如通过抑制HTLV-1诱导的合胞体形成和体外转化测定所确定的。使用重叠寡肽的抗体结合测定揭示KE 36 -11识别位于gp 46氨基酸序列187-193（Ala-Pro-Pro-Leu-Leu-Pro-His）之间的新表位。另一种抗gp 46单克隆抗体，命名为KE 36 -7，显示对HTLV-1携带细胞系的抗体依赖性细胞毒性。KE 36 -7与10-mer肽-gp 46 187-196强结合，与含有gp 46氨基酸序列191-196（Leu-Pro-His-Ser-Asn-Leu）的肽弱结合。这两个表位与HTLV-1中和和抗体依赖性细胞毒性相关，因此是在人HTLV-1感染中鉴定的第一个表位。这两种人源单克隆抗体被动免疫人可能对HTLV-1感染的体内保护有效。
We have generated a number of EBV-transformed B cell lines producing human mAb against human T cell leukemia virus type 1 (HTLV-1) from the peripheral blood B lymphocytes obtained from patients with HTLV-1-associated myelopathy/tropical spastic paraparesis. Various synthetic peptides corresponding to antigenic regions of HTLV-1 gag and env proteins were used for the screening of antibodies in ELISA. In our study, four IgG mAb to the gag p19 amino acids 100 to 130, and 5 IgG mAb to the env p46 amino acids 175 to 199 were characterized. An immunofluorescence assay showed that all of these mAb specifically bound to the surface of HTLV-1-bearing cell lines. Among these mAb, one anti-gp46 mAb, designated KE36-11, neutralized the infectivity of HTLV-1 as determined by both the inhibition of HTLV-1-induced syncytium formation and transformation assays in vitro. An antibody-binding assay using overlapping oligopeptides revealed that KE36-11 recognized a new epitope locating between the gp46 amino acid sequence 187-193 (Ala-Pro-Pro-Leu-Leu-Pro-His). Another anti-gp46 mAb, designated KE36-7, showed antibody-dependent cellular cytotoxicity against HTLV-1-bearing cell line. KE36-7 bound strongly to the 10-mer peptide-gp46 187-196, and weakly to peptides containing the gp46 amino acid sequence 191-196 (Leu-Pro-His-Ser-Asn-Leu). These two epitopes, which are associated with HTLV-1 neutralization and antibody-dependent cellular cytotoxicity, are thus the first epitopes identified in human HTLV-1 infection. It is possible that passive immunization of humans with these two human mAb are effective on the protection of HTLV-1 infection in vivo.