Piret B, Legrand-Poels S, Sappey C, Piette J
Laboratory of Virology, University of Liège, Belgium.
Eur J Biochem. 1995 Mar 1;228(2):447-55.
Reactive oxygen species like hydrogen peroxide (H2O2) have been shown to serve as messengers in the induction of NF-kappa B and then in the activation and replication of HIV-1 in human cells. Because singlet oxygen (1O2) is another very important reactive oxygen species whose action in transcription factor activation is totally undetermined, we started to investigate its role in both NF-kappa B and HIV-1 activation. For provoking unbalanced redox conditions, 1O2 was generated by photosensitization using methylene blue as photosensitizer. Lymphocytes or monocytes (ACH-2 or U1 respectively) latently infected with HIV-1 were treated by photosensitization mediated by methylene blue and the production of reactive oxygen species was monitored through their cytotoxic effect in infected cells. The generation of 1O2 by methylene blue turns out to be very efficient in inducing NF-kappa B as a heterodimer composed of the p50 and p65 subunits. This induction appears specific since other transcription factors like AP-1 are only weakly activated by this treatment. In comparison with other inducing treatments such as phorbol esters or tumor necrosis factor alpha (TNF-alpha), the methylene-blue-mediated activation of NF-kappa B is slow, becoming optimal 180 min after treatment. These kinetic data were obtained by following, on the same samples, both the emergence of NF-kappa B in the nucleus and the disappearance of I kappa B-alpha in the cytoplasmic extracts. Conjugated with the induction of this transcription factor, HIV-1 reactivation from these latently infected cells was also observed by the measurement of reverse transcriptase activity in the cell supernatants. These data allow us to postulate that 1O2 is a biologically important reactive oxygen species which could play a role in the establishment of oxidative stress conditions leading to HIV-1 activation via the presence of NF-kappa B in the nucleus of infected cells.
像过氧化氢（H2O2）这样的活性氧已被证明在诱导核因子κB（NF-κB）以及随后在人类细胞中激活和复制HIV-1的过程中充当信使。由于单线态氧（1O2）是另一种非常重要的活性氧，其在转录因子激活中的作用完全未知，我们开始研究它在NF-κB和HIV-1激活中的作用。为了引发不平衡的氧化还原条件，使用亚甲蓝作为光敏剂通过光致敏产生1O2。用亚甲蓝介导的光致敏处理潜伏感染HIV-1的淋巴细胞或单核细胞（分别为ACH-2或U1），并通过它们对感染细胞的细胞毒性作用监测活性氧的产生。结果表明，亚甲蓝产生1O2在诱导由p50和p65亚基组成的异二聚体NF-κB方面非常有效。这种诱导似乎具有特异性，因为其他转录因子如AP-1仅被这种处理微弱激活。与其他诱导处理如佛波酯或肿瘤坏死因子α（TNF-α）相比，亚甲蓝介导的NF-κB激活较慢，在处理后180分钟达到最佳状态。这些动力学数据是通过在同一样品上跟踪细胞核中NF-κB的出现和细胞质提取物中IκB-α的消失而获得的。与这种转录因子的诱导相结合，通过测量细胞上清液中的逆转录酶活性，还观察到了这些潜伏感染细胞中HIV-1的重新激活。这些数据使我们能够推测，1O2是一种生物学上重要的活性氧，它可能在导致通过感染细胞核中存在NF-κB而激活HIV-1的氧化应激条件的建立中发挥作用。
