THE EFFECT OF DNA DEMETHYLATION HIV-1 EXPRESSION IN VITRO

DNA去甲基化对人类免疫缺陷病毒1型的影响 研究了(H-1)IV在几种感染的细胞系中的表达 HIV-1在体外。为了使前病毒DNA去甲基化，5-氮胞苷 (AZC)及其类似物。一个持续感染艾滋病毒-1的人 T细胞系ACH2在体外产生低水平的HIV-1。然而， 在暴露于AZC或其类似物后， 通过合胞体形成和检测病毒表达 逆转录酶和p24 Gag蛋白的产生。交替使用 ACH2中前病毒DNA的甲基化模式被证实 甲基化敏感/不敏感的Southern杂交 同裂解物限制性内切酶。 AZC诱导的病毒表达增强在任何 高HIV-1产生者，慢性HIV-1感染H9细胞，亚急性 HIV-1感染正常的CD4+T细胞，或亚急性感染 凝集素激活的外周血单核细胞。Southern印迹 杂交显示，在这些高度产生HIV-1的人中，前病毒DNA 细胞已经被广泛地去甲基化，并且没有改变DNA AZC治疗后出现了甲基化模式。我们还发现 AZC本身的固有毒性，至少部分是， 与观察到的ACH2中HIV-1表达的增强有关 细胞。目前的数据表明，DNA甲基化可能在 至少在某些情况下调控HIV-1的表达。 进一步的研究也是有必要的，以测试某些 对细胞产生毒性的治疗药物，如抗癌剂，可能 影响HIV-1感染患者HIV-1的表达 肿瘤。

The effect of DNA demethylation on human immunodeficiency virus type-1 (H-1)IV expression was investigated in several cell lines infected with HIV-1 in vitro. In order to demethylate proviral DNA, 5-azacytidine (AZC) and its analog were employed. A persistently HIV-1-infected T-cell line, ACH2, produced a low level of HIV-1 in vitro. However, following exposure to AZC or its analog, a profound potentiation of viral expression occurred as assessed by syncytia formation and production of reverse transcriptase and p24 Gag protein. Alternation in the methylation pattern of proviral DNA in ACH2 was confirmed by Southern blot hybridization using methylation sensitive/insensitive isoschizomer restriction enzymes. AZC-induced potentiation of viral expression did not occur in any of high HIV-1-producers, chronically HIV-1 infected H9 cells, subacutely HIV-1-infected normal CD4+ T-cells, or subacutely infected lectin-activated peripheral blood mononuclear cells. Southern blot hybridization revealed that proviral DNA in these highly HIV-1-producing cells had already been extensively demethylated, and no altered DNA methylation pattern had occurred following AZC treatment. We also found that the inherent toxicity of AZC per se was, at least in part, associated with the observed enhancement of HIV-1 expression in ACH2 cells. The present data suggest that DNA methylation may play a role in regulating HIV-1 expression at least under certain circumstances. Further study is also warranted to test the possibility that certain therapeutics which exert toxicity to cells such as anticancer agents may affect the expression of HIV-1 in patients with HIV-1 infection and neoplasms.