Models for KHSV transmission and its inhibition

摘要 卡波西肉瘤（KS）是一种高度流行的恶性肿瘤在撒哈拉以南非洲。这种癌症， 卡波西肉瘤疱疹病毒（KSHV）作为病原体，在HIV-1中的发病率增加 尽管抗逆转录病毒（ART）抑制HIV-1病毒载量，但仍有感染患者。它也作为一种 HIV阴性人群中的侵袭性肿瘤。我们的团队一直在研究KS和KSHV 在KS流行国家的传播，我们已经表明KSHV感染是获得性的， 主要在幼儿期，HIV-1感染是一个主要危险因素， 传染性唾液是可能的传播机制。最近，我们在赞比亚和 坦桑尼亚证明，高滴度中和抗体应答（nAb）主要发生在个体中， 与感染的无症状个体相反，有症状的KS，这表明nAb不是一种免疫抑制剂。 KS的保护。因此，与HIV-1病毒-宿主相互作用非常相似，KSHV似乎 nAb不能预防长期慢性感染后的疾病。然而， 被动给予广泛nAb已在HIV-1/SIV感染激发模型中得到证实; 然而，预先存在的nAb预防KSHV传播的能力尚未测试。此外，虽然 在体外KSHV进入过程中已经研究了一定的深度，精确的病毒和细胞的相互作用， 在组织水平上参与KSHV，尚未明确阐明。在某种程度上，这种知识差距 这是由于缺乏人体KSHV传播的体内模型。拟议项目适用于 我们的团队对KS，KSHV，人KSHV Ab应答和KSHV感染的长期经验， 我们开发的人源化小鼠模型，以解决KSHV造成的知识缺口 传播和传播。我们的总体目标是确定免疫反应， 防止KSHV感染和传播，从而预防KS。我们的假设是 KSHV nAb可在离体人类器官型组织模型中保护KSHV传播 以及在KSHV感染的人源化小鼠模型中。该假设将通过3个具体目标进行检验： 1)开发器官型口腔和阴道上皮细胞培养模型以了解KSHV传播 动力学，并测试具有高nAb滴度的血清是否预防跨上皮KSHV感染; 2）测试 KSHV nAb在粘膜和血液暴露的人源化BLT-小鼠模型中是否具有保护性， KHSV感染和传播; 3）分离人单克隆KSHV nAb， 描述其对KSHV传播的影响。该项目将阐明 KSHV的传播和传播，并为开发疫苗的战略奠定基础， 预防KSHV感染。最终，这些研究将扩大我们预防KSHV感染的能力 和相关的肿瘤。

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 neutralizing Ab responses (nAb) develop primarily in individuals with 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 of 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.