Models for KHSV transmission and its inhibition

摘要 卡波西肉瘤（KS）是撒哈拉以南非洲地区高度流行的恶性肿瘤。这种癌症， 以卡波西肉瘤疱疹病毒 (KSHV) 为病原体的该病的发病率有所增加 尽管抗逆转录病毒 (ART) 抑制了 HIV-1 病毒载量，但仍感染 HIV-1 的患者。它还 在 HIV 阴性人群中作为侵袭性肿瘤发生。我们团队一直在研究KS 以及 KSHV 在 KS 流行国家的传播，我们已经表明 KSHV 感染是 HIV-1 感染主要发生在儿童早期，是一个主要危险因素， 粘膜接触传染性唾液是可能的传播机制。最近， 我们在赞比亚和坦桑尼亚的结果表明，具有症状 KS 的高滴度中性粒细胞 与感染的无症状个体相反，表明 nAb 与 KS 无关 保护。因此，就像 HIV-1 病毒与宿主的相互作用一样，KSHV nAb 似乎不能 预防长期慢性感染后的疾病。然而，预防能力 抗体反应 (nAb) 主要在被动广泛施用 nAb 的个体中产生 在 HIV-1/SIV 感染挑战模型中得到证实；然而，预先的能力 现有的防止 KSHV 传播的 nAb 未经测试。此外，虽然体外 KSHV 进入过程已得到一定程度的深入研究，病毒和细胞的精确相互作用 KSHV 在组织水平上的参与，尚未明确阐明。在某种程度上，这些知识 差距是由于缺乏人类 KSHV 传播的体内模型造成的。拟议的 项目应用了我们团队在 KS、KSHV、人类 KSHV 抗体反应方面的长期经验， 和 KSHV 感染 我们开发的人性化小鼠模型，旨在解决由 KSHV 传播和传播。我们的总体目标是识别免疫反应 可以防止 KSHV 感染和传播，从而预防 KS。我们的 假设 KSHV nAb 可以预防 KSHV 在离体人体中的传播 器官型组织模型和 KSHV 感染的人源化小鼠模型。假设 将针对 3 个具体目标进行测试：1) 开发器官型口腔和阴道上皮培养物 模型来了解 KSHV 传播动力学并测试血清是否具有高 nAb 滴度 预防跨上皮 KSHV 感染； 2) 测试 KSHV nAb 在人源化抗体中是否具有保护作用 BLT-小鼠粘膜和血液暴露、KHSV 感染和传播模型，以及 3) 人单克隆 KSHV nAb 的分离及其对 KSHV 影响的表征 传输。该项目将阐明 KSHV 传播和传播的机制， 并为开发预防 KSHV 感染的疫苗的策略奠定基础。 最终，此类研究将扩大我们预防 KSHV 感染及相关疾病的能力 肿瘤。

ABSTRACT Kaposi's sarcoma (KS) is a highly prevalent malignancy in sub-Saharan Africa. This cancer, with Kaposi's sarcoma herpesvirus (KSHV) as the etiologic agent, is at increased incidence in HIV-1 infected patients despite antiretroviral (ART) suppression of HIV-1 viral load. It also occurs as an aggressive tumor in the HIV-negative population. Our team has been studying KS and KSHV transmission in KS endemic countries and we have shown that KSHV infection is acquired predominantly in early childhood, HIV-1 infection is a major risk factor, and that mucosal exposure to infectious saliva is the likely mechanism of transmission. More recently, our results from Zambia and Tanzania demonstrated that high titer neutwith symptomatic KS as opposed to infected asymptomatic individuals, suggesting that nAb is not a correlate of KS protection. Thus, much like in the HIV-1 virus-host interaction, it appears that KSHV nAb cannot prevent disease after long-term chronic infection. However, the prophylactic capacity ofralizing Ab responses (nAb) develop primarily in individuals passively administered broadly nAb has been demonstrated in HIV-1/SIV infectious challenge models; whereas, the ability of pre- existing nAb to prevent KSHV transmission is untested. In addition, while the in vitro KSHV entry process has been studied in some depth, the precise viral and cellular interactions involved in KSHV at the tissue level, have not been clearly elucidated. In part, this knowledge gap results from the lack of an in vivo model of human KSHV transmission. The proposed project applies our team's long-term experience with KS, KSHV, human KSHV Ab responses, and KSHV infection in a humanized mouse model that we have developed, to address the knowledge gap posed by KSHV transmission and dissemination. Our overall objective is to identify immune response(s) that can protect against KSHV infection and transmission, and thereby, prevent KS. Our hypothesis is that KSHV nAb can be protective against KSHV transmission in ex vivo human organotypic tissue models and in a humanized mouse model of KSHV infection. The hypothesis will be tested with 3 specific aims: 1) Develop organotypic oral and vaginal epithelial culture models to understand KSHV transmission dynamics and to test whether sera with high nAb titer prevents trans-epithelial KSHV infection; 2) test whether KSHV nAb is protective in a humanized BLT-mouse model of mucosal and blood exposure, infection and dissemination of KHSV, and 3) isolation of human monoclonal KSHV nAb and characterization of their impact on KSHV transmission. This project will clarify the mechanisms of KSHV transmission and dissemination, and lay the foundations for strategies to develop a vaccine to prevent KSHV infection. Ultimately, such studies will expand our capacity to prevent KSHV infection and associated neoplasms.