Production of interferon α by human immunodeficiency virus type 1 in human plasmacytoid dendritic cells is dependent on induction of autophagy.
Production of interferon α by human immunodeficiency virus type 1 in human plasmacytoid dendritic cells is dependent on induction of autophagy.
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DOI：
10.1093/infdis/jis187
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发表时间：
2012-04
期刊：
影响因子：
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通讯作者：
Dejiang Zhou;K. Kang;S. Spector
中科院分区：
文献类型：
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作者：
Dejiang Zhou;K. Kang;S. Spector
背景 在人类免疫缺陷病毒 1 型 (HIV-1) 感染期间，浆细胞样树突状细胞 (pDC) 产生干扰素 α (IFN-α) 的机制尚不清楚。这项研究探讨了 HIV-1 感染期间 Toll 样受体 7 (TLR7) 和自噬在 pDC 产生 IFN-α 中的作用。方法将人外周血单核细胞的 pDC 与感染性或 Aldrithiol 2 (AT-2) 灭活的 HIV-1 或来自 HIV-1 长末端重复序列的富含尿苷的单链 RNA40 (ssRNA40) 一起孵育。通过酶联免疫吸附测定对 IFN-α 进行定量。通过蛋白质印迹检测自噬蛋白，并使用免疫荧光和共聚焦显微镜鉴定自噬体。为了抑制自噬，pDC 用磷酸肌醇 3 激酶抑制剂 3-甲基腺嘌呤 (3-MA) 处理，或用自噬相关蛋白 7 或 TLR7 小干扰 RNA (siRNA) 转染。结果 pDC 与感染性或 AT-2 灭活的 HIV-1 一起孵育 16 小时后，培养物上清液中 IFN-α 的水平增加。用 ssRNA40 而不是 ssRNA41 处理 pDC 会导致高水平的 IFN-α。单独暴露于 HIV-1 gp120、雷帕霉素或 3-MA 的 pDC 未能诱导 IFN-α。用 3-MA 预处理 pDC 显着降低 ssRNA40 对 IFN-α 的诱导。同样，使用 siRNA 敲低自噬相关蛋白 7 和 TLR7 显着降低了 ssRNA40 或 HIV-1 对 IFN-α 的诱导。结论 这些发现表明，暴露于感染性或非感染性 HIV-1 和 ssRNA40 的 pDC 产生 IFN-α 是通过 TLR7 信号转导后诱导自噬而发生的。
BACKGROUND The mechanisms responsible for interferon α (IFN-α) production by plasmacytoid dendritic cells (pDCs) during human immunodeficiency virus type 1 (HIV-1) infection are unknown. This research examined the roles of Toll-like receptor 7 (TLR7) and autophagy in IFN-α production by pDCs during HIV-1 infection. METHODS pDCs from human peripheral blood mononuclear cells were incubated with infectious or aldrithiol 2 (AT-2)-inactivated HIV-1 or with uridine-rich single-stranded RNA40 (ssRNA40) from the HIV-1 long terminal repeat. IFN-α was quantified by enzyme-linked immunosorbant assay. Autophagic proteins were detected by Western blot, and autophagosomes were identified using immunofluorescent and confocal microscopy. To inhibit autophagy, pDCs were treated with the phosphoinositide-3 kinase inhibitor 3-methyladenine (3-MA) or were transfected with autophagy-related protein 7 or TLR7 small interfering RNA (siRNA). RESULTS Increased levels of IFN-α were present in culture supernatants following 16-hour incubation of pDCs with infectious or AT-2-inactivated HIV-1. Treatment of pDCs with ssRNA40 but not ssRNA41 resulted in high levels of IFN-α. pDCs exposed to HIV-1 gp120, rapamycin, or 3-MA alone failed to induce IFN-α. Pretreatment of pDCs with 3-MA significantly reduced the induction of IFN-α by ssRNA40. Similarly, knock down of autophagy-related protein 7 and TLR7 by use of siRNA significantly reduced the induction of IFN-α by ssRNA40 or HIV-1. CONCLUSIONS These findings demonstrate that IFN-α production by pDCs exposed to infectious or noninfectious HIV-1 and ssRNA40 occurs through induction of autophagy following TLR7 signaling.