Lacoste J, D'Addario M, Roulston A, Wainberg M A, Hiscott J
Lady Davis Institute for Medical Research Sir Mortimer B. Davis Jewish General Hospital, Department of Microbiology and Immunology, Montreal, Quebec, Canada.
J Virol. 1990 Oct;64(10):4726-34. doi: 10.1128/JVI.64.10.4726-4734.1990.
Three aspects of the involvement of tumor necrosis factor in human immunodeficiency virus (HIV) pathogenesis were examined. Tumor necrosis factor alpha (TNF-alpha) mRNA production was analyzed by polymerase chain reaction amplification in monocytic U937 cells and in a chronically HIV infected U937 cell line (U9-IIIB). TNF-alpha RNA was undetectable in U937 cells, whereas a low constitutive level was detected in U9-IIIB cells. Paramyxovirus infection induced a 5- to 10-fold increase in the steady-state level of TNF-alpha RNA in U9-IIIB cells compared with U937 cells, suggesting that HIV-infected monocytic cells produced higher levels of TNF-alpha than did normal cells after a secondary virus infection. The effects of TNF-alpha on gene expression were examined by transient expression assays using reporter chloramphenicol acetyltransferase plasmids linked to regulatory elements from the HIV long terminal repeat (LTR) and the beta interferon promoter. In U937 and Jurkat T lymphoid cells, the inducibility of the different hybrid promoters by TNF-alpha or phorbol ester varied in a cell type- and promoter context-specific manner; the levels of gene activity of NF-kappa B-containing plasmids correlated directly with induction of NF-kappa B DNA-binding activity. Although the intact beta interferon promoter was only weakly stimulated by phorbol ester or TNF-alpha, multimers of the PRDII NF-kappa B-binding domain were inducible by both agents. TNF-alpha was able to increase expression of the HIV LTR in T cells, but in monocytic cells, TNF-alpha did not induce the HIV LTR above a constitutive level of activity. This level of NF-kappa B-independent activity appears to be sufficient for virus multiplication, since TNF-alpha treatment had no effect on the kinetics of de novo HIV type 1 (HIV-1) infection and viral RNA production in U937 cells. However, in Jurkat cells, TNF-alpha dramatically enhanced the spread of HIV-1 through the cell population and increased viral RNA synthesis, indicating that in T cells HIV-1 multiplication was stimulated by TNF-alpha treatment.
研究了肿瘤坏死因子在人类免疫缺陷病毒（HIV）发病机制中的三个方面。通过聚合酶链反应扩增分析单核细胞U937细胞和慢性HIV感染的U937细胞系（U9-IIIB）中肿瘤坏死因子α（TNF-α）mRNA的产生。在U937细胞中未检测到TNF-α RNA，而在U9-IIIB细胞中检测到低水平的组成性表达。与U937细胞相比，副粘病毒感染使U9-IIIB细胞中TNF-α RNA的稳态水平增加了5至10倍，这表明HIV感染的单核细胞在继发病毒感染后产生的TNF-α水平高于正常细胞。使用与HIV长末端重复序列（LTR）和β干扰素启动子的调控元件相连的报告氯霉素乙酰转移酶质粒，通过瞬时表达分析研究了TNF-α对基因表达的影响。在U937和Jurkat T淋巴细胞中，TNF-α或佛波酯对不同杂交启动子的诱导能力因细胞类型和启动子背景而异；含NF-κB质粒的基因活性水平与NF-κB DNA结合活性的诱导直接相关。尽管完整的β干扰素启动子仅受到佛波酯或TNF-α的微弱刺激，但PRDII NF-κB结合域的多聚体可被这两种试剂诱导。TNF-α能够增加T细胞中HIV LTR的表达，但在单核细胞中，TNF-α并未诱导HIV LTR高于组成性活性水平。这种不依赖NF-κB的活性水平似乎足以支持病毒增殖，因为TNF-α处理对U937细胞中1型HIV（HIV-1）的初始感染动力学和病毒RNA产生没有影响。然而，在Jurkat细胞中，TNF-α显著增强了HIV-1在细胞群体中的传播并增加了病毒RNA合成，这表明在T细胞中，TNF-α处理刺激了HIV-1的增殖。
