Kaposi's sarcoma-associated herpesvirus interacts with EphrinA2 receptor to amplify signaling essential for productive infection
Kaposi's sarcoma-associated herpesvirus interacts with EphrinA2 receptor to amplify signaling essential for productive infection
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DOI：
10.1073/pnas.1119592109
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发表时间：
2012-05-08
影响因子：
11.1
通讯作者：
Chandran, Bala
中科院分区：
文献类型：
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作者：
Chakraborty, Sayan;Veettil, Mohanan Valiya;Chandran, Bala
卡波西肉瘤相关疱疹病毒（KSHV），在病因学上与卡波西肉瘤相关，使用整合素（α 3 β 1，α V β 3和α V β 5）和相关信号进入人真皮微血管内皮细胞（HMVEC-d），体内感染的目标。KSHV感染激活c-Cbl，其诱导KSHV与α 3 β 1、α V β 3和xCT受体沿着选择性易位到脂筏（LR）中，但不诱导α V β 5。LR易位受体被单泛素化，导致生产性巨胞饮细胞进入，而非LR相关的α V β 5被多泛素化，导致靶向溶酶体的网格蛋白介导的进入。由于整合信号通路和生产性KSHV巨胞饮的分子是未知的，我们用抗α 3 β 1抗体免疫沉淀KSHV感染的LR组分，并通过质谱法对其进行分析。酪氨酸激酶EphrinA 2（EphA 2），涉及许多癌症，在这项分析中被确定。EphA 2被KSHV激活。EphA 2还与感染早期LR中的KSHV和整合素（α 3 β 1和α V β 3）相关。病毒与可溶性EphA 2的预孵育、通过shRNA敲低EphA 2或用抗EphA 2单克隆抗体或酪氨酸激酶抑制剂达沙替尼预处理细胞显著降低KSHV进入和基因表达。EphA 2与c-Cbl-肌球蛋白IIA结合，增强了LR中KSHV诱导的Src和PI 3-K信号，导致KSHV的水泡形成和巨胞饮作用。EphA 2 shRNA消除了巨胞饮相关的信号事件，病毒内化和KSHV DNA的生产性核运输。总之，这些研究表明EphA 2受体作为KSHV诱导的信号分子和KSHV进入内皮细胞的主装配调节剂，并表明EphA 2受体是控制KSHV感染的有吸引力的靶标。
Kaposi's sarcoma-associated herpesvirus (KSHV), etiologically associated with Kaposi's sarcoma, uses integrins (alpha 3 beta 1, alpha V beta 3, and alpha V beta 5) and associated signaling to enter human dermal microvascular endothelial cells (HMVEC-d), an in vivo target of infection. KSHV infection activated c-Cbl, which induced the selective translocation of KSHV into lipid rafts (LRs) along with the alpha 3 beta 1, alpha V beta 3, and xCT receptors, but not alpha V beta 5. LR-translocated receptors were monoubiquitinated, leading to productive macropinocytic entry, whereas non-LR-associated alpha V beta 5 was polyubiquitinated, leading to clathrin-mediated entry that was targeted to lysosomes. Because the molecule(s) that integrate signal pathways and productive KSHV macropinocytosis were unknown, we immunoprecipitated KSHV-infected LR fractions with anti-alpha 3 beta 1 antibodies and analyzed them by mass spectrometry. The tyrosine kinase EphrinA2 (EphA2), implicated in many cancers, was identified in this analysis. EphA2 was activated by KSHV. EphA2 was also associated with KSHV and integrins (alpha 3 beta 1 and alpha V beta 3) in LRs early during infection. Preincubation of virus with soluble EphA2, knockdown of EphA2 by shRNAs, or pretreatment of cells with anti-EphA2 monoclonal antibodies or tyrosine kinase inhibitor dasatinib significantly reduced KSHV entry and gene expression. EphA2 associates with c-Cbl-myosin IIA and augmented KSHV-induced Src and PI3-K signals in LRs, leading to bleb formation and macropinocytosis of KSHV. EphA2 shRNA ablated macropinocytosis-associated signaling events, virus internalization, and productive nuclear trafficking of KSHV DNA. Taken together, these studies demonstrate that the EphA2 receptor acts as a master assembly regulator of KSHV-induced signal molecules and KSHV entry in endothelial cells and suggest that the EphA2 receptor is an attractive target for controlling KSHV infection.