Hanon E, Asquith R E, Taylor G P, Tanaka Y, Weber J N, Bangham C R
Department of Immunology, Imperial College School of Medicine, St Mary's campus, London W21PG, United Kingdom.
AIDS Res Hum Retroviruses. 2000 Nov 1;16(16):1711-5. doi: 10.1089/08892220050193191.
Most human T cell lymphotropic virus type (HTLV)-1-infected individuals mount a strong and persistently activated cytotoxic T lymphocyte (CTL) response to the virus, which implies that there is abundant chronic transcription of HTLV-1 genes. On the other hand, several observations suggest that HTLV-1 might be latent in vivo and therefore not detectable by CTLs. To clarify these discrepancies, we quantified the frequency of provirus-positive peripheral blood mononuclear cells (PBMCs) that were capable of expressing the HTLV-1 Tax protein, which is known to be the immunodominant target antigen recognized by HTLV-1-specific CTLs. The analysis showed that a significant proportion of HTLV-1-infected cells (from 14 to 100%) starts to express the Tax protein within a few hours of culture ex vivo. Phenotypic analysis confirmed that the main cell subpopulation expressing the Tax protein is CD4 positive. Frequent Tax expression in CD4(+) T lymphocytes in vivo might account for the chronic activation of the cytotoxic immune response observed in the majority of HTLV-1-infected patients and might contribute to the pathogenesis of HTLV-1-associated diseases.
大多数感染人类嗜T淋巴细胞病毒1型（HTLV-1）的个体对该病毒会产生强烈且持续激活的细胞毒性T淋巴细胞（CTL）反应，这意味着HTLV-1基因存在大量的慢性转录。另一方面，一些观察结果表明HTLV-1在体内可能处于潜伏状态，因此无法被CTL检测到。为了阐明这些差异，我们对能够表达HTLV-1 Tax蛋白的前病毒阳性外周血单个核细胞（PBMC）的频率进行了量化，已知Tax蛋白是HTLV-1特异性CTL识别的免疫显性靶抗原。分析表明，相当比例的HTLV-1感染细胞（14%至100%）在离体培养的几小时内开始表达Tax蛋白。表型分析证实，表达Tax蛋白的主要细胞亚群是CD4阳性。体内CD4(+) T淋巴细胞中Tax蛋白的频繁表达可能是大多数HTLV-1感染患者中观察到的细胞毒性免疫反应慢性激活的原因，并且可能促成HTLV-1相关疾病的发病机制。
