Early events of in vitro KSHV infection

描述（由申请人提供）：我们对动物病毒与细胞表面受体的相互作用如何促进生产性感染的理解存在根本性差距。病毒（如疱疹病毒）与细胞表面的结合可以在40 ℃以能量不依赖的方式发生。相反，衣壳进入细胞并随后转移到细胞核附近是一种活跃的能量依赖性现象，因此必须需要宿主细胞信号传导途径。我们的中心假设是KSHV已经进化到利用其与受体的相互作用来操纵宿主预先存在的信号级联来介导靶细胞的进入和感染。我们正在进行的研究支持这一假设。我们已经表明，在感染内皮细胞（HMVEC-d），KSHV的初始附着发生通过硫酸乙酰肝素（HS），其次是时间的相互作用与整合素（？三个？1，？？小维？3、？小维？5)和xCT分子。KSHV结合导致FAK，Src，PI3-K，Rho-GTP酶，Dia-2，Ezrin，PKC-β，ERK 1/2和NF-？B信号分子。这些分子在KSHV进入（FAK、Src、PI3-K、Rho-GTP酶）、微管（MT）的乙酰化（RhoA-GTP酶）（其促进KSHV衣壳通过动力蛋白马达向核的运输）和病毒基因表达（ERK 1/2和NF-？B）。虽然脂筏（LR）破坏导致增加Src激活和病毒进入，我们观察到抑制病毒基因表达，PI3K，RhoA，Dia-2和NF？B激活、MT乙酰化和病毒DNA的核递送，这表明LRs在进入细胞和调节选定的信号分子中起作用。我们还证明了c-Cbl在KSHV巨胞饮中发挥作用。 为了进一步验证我们的假设，我们制定了三个主要的相互关联的，集中的具体目标，这将破译的机制，c-Cbl促进KSHV进入，主要衔接分子在KSHV感染的作用，并破译c-Cbl如何决定含有KSHV的巨胞饮体的命运。 这些研究意义重大，因为对KSHV感染早期事件的全面了解将提供新的靶点来阻断KSHV引起的靶细胞感染和相关疾病。

DESCRIPTION (provided by applicant): There is a fundamental gap in our understanding of how animal virus interactions with cell surface receptors facilitate a productive infection. Bindin of viruses, such as herpesviruses, to the cell surface can occur at 40C in an energy independent manner. In contrast, entry into cells and subsequent transfer of capsids to the vicinity of the nucleus are an active, energy dependent phenomenon, and thus must require host-cell signaling pathways. Our central hypothesis is that KSHV has evolved to utilize its interactions with receptors to manipulate the host's pre-existing signal cascades to mediate entry and infection of target cells. Our ongoing studies support this hypothesis. We have shown that during infection of endothelial (HMVEC-d) cells, the initial attachment of KSHV occurs via heparan sulfate (HS) followed by a temporal interaction with integrins (?3?1,??V??3, and ?V??5) and xCT molecules. KSHV binding resulted in the activation of FAK, Src, PI3-K, Rho-GTPases, Dia-2, Ezrin, PKC-?, ERK1/2 and NF-?B signal molecules. These molecules play roles in KSHV entry (FAK, Src, PI3-K, Rho-GTPases), acetylation of microtubules (MT) (RhoA-GTPase) that facilitates the transport of KSHV capsid toward the nucleus via dynein motors, and viral gene expression (ERK1/2 and NF-?B). Although lipid raft (LR) disruption resulted in increased Src activation and virus entry, we observed the inhibition of viral gene expression, PI3K, RhoA, Dia-2 and NF?B activation, MT acetylation and nuclear delivery of viral DNA which suggested that LRs play roles in entry in cells and modulates selected signal molecules. We have also demonstrated that c-Cbl play a role in KSHV macropinocytosis. To further test our hypothesis, we have formulated three major interlinked, focused specific aims which will decipher the mechanisms by which c-Cbl facilitate KSHV entry, the role of major adaptor molecules in KSHV infection and decipher how c-Cbl dictates the fate of macropinosomes containing KSHV. These studies are significant since such comprehensive understanding of early events of KSHV infection will provide novel targets to block the initiation of target cell infection by KSHV and te associated diseases.