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 以卡波西肉瘤疱疹病毒（KSHV）为病原体， 尽管抗逆转录病毒（ART）抑制了HIV-1病毒载量，但仍有HIV-1感染患者。它还 在HIV阴性人群中作为侵袭性肿瘤发生。我们的团队一直在研究KS 和KSHV的传播，我们已经表明，KSHV感染是 主要在幼儿期获得，HIV-1感染是一个主要的风险因素， 粘膜暴露于感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研究结果表明，高滴度中性粒细胞与有症状的KS一样， 与感染的无症状个体相反，表明nAb与KS无关 保护因此，与HIV-1病毒-宿主相互作用非常相似，KSHV nAb似乎不能 预防长期慢性感染后的疾病。然而， 抗体应答（nAb）主要发生在被动广泛给予nAb的个体中， 在HIV-1/SIV感染性攻击模型中得到证实;然而， 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 缺口是由于缺乏人KSHV传播的体内模型。拟议 项目应用了我们团队在KS、KSHV、人KSHV Ab应答方面的长期经验， 和KSHV感染 我们已经开发的人源化小鼠模型，以解决知识差距造成的， KSHV传播和传播。我们的总体目标是确定免疫反应 可以防止KSHV感染和传播，从而预防KS。我们 假设KSHV nAb可以在离体人中保护免于KSHV传播 器官型组织模型和KSHV感染的人源化小鼠模型。的假设 将以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，以了解KSHV传播动力学，并测试是否具有高nAb滴度的血清 预防跨上皮KSHV感染; 2）测试KSHV nAb是否在人源化KSHV中具有保护性。 粘膜和血液暴露、KHSV感染和传播的BLT-小鼠模型，以及3） 人源KSHV单克隆抗体分离及其对KSHV的影响 传输该项目将澄清KSHV传播和传播的机制， 并为开发预防KSHV感染的疫苗奠定基础。 最终，这些研究将扩大我们预防KSHV感染和相关疾病的能力。 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.