MECHANISMS OF VERTICAL TRANSMISSION OF HIV-1

HIV-1 垂直传播机制

• 批准号: 2076250
• 负责人: Omar Bagasra
• 金额: $ 15.83万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-30 至 1997-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2076250
• 关键词: amnion; embryo /fetus; female; genetic transcription; human immunodeficiency virus 1; human subject; newborn animals; perinatal; placenta; placental transfer; polymerase chain reaction; provirus; vertical transmission; virus DNA; virus load

Mother to child transmission of HIV-1 occurs in 15-40% of children born to HIV-1 seropositive mothers. It remains unclear why some others transmit HIV-1 to their infants while the majority do not. Studies to date indicate multiple factors associated with maternal-fetal transmission including plasma viremia, maternal immune response, maternal viral phenotypes, use of anti-retroviral agents during pregnancy, and obstetrical. Little is known of the mode of transmission or risk factors associated with transmission in utero. Identification of the role played by the placenta in maternal-fetal transmission of HIV-1 may lead to the development of strategies to prevent transplacental infection of the fetus. It is our hypothesis that: (i) the HIV-1 viral load is higher in the placentas of mothers with high plasma viremia during pregnancy resulting in higher rates of transmission; and (ii) early elimination of HIV-1 infected cells in the PBMCs of newborns results in long-term asymptomatic survivors whereas failure to do so results in the early manifestation of AIDS. In this application, we propose to (i) examine the correlation between PBMC/plasma viral burden during pregnancy and the viral burden of the placenta at the chorioamniotic layer at delivery; and (ii) examine the viral burden of the newborn at the time of delivery and throughout the first six months of life in correlation with the subsequent clinical development of HIV-1 related disease. 1. Determination of viral burden in maternal PBMCs and placental tissue. We will analyze the viral burden in: (i) circulating maternal PBMCs during pregnancy by determining the percentage of cells carrying proviral DNA by in situ DNA-PCR and viral burden by plasma quantitative branched chain DNA signal amplification. Further, we will determine the relative transcriptional activity of those infected cells by examination of HIV-1 specific RNA (spliced and unspliced) by reverse transcriptase in situ PCR, in situ hybridization, and branched chain DNA amplification. Similarly, (ii) we will analyze the viral burden within placental tissue from the corresponding mothers in conjunction with histologic typing within the various placental layers, especially at the chorioamnion. Finally, we will determine the origin (maternal versus fetal) of infected cells by simultaneous tissue typing of infected cells by in situ DNA PCR for HLA- DQA and HLA-DRB1 antigens. 2. Determination of viral burden in newborn PBMCs in relation to disease development. We will analyze cord blood, plasma as well as circulating PBMCs from the newborn to determine proviral burden and transcriptional activity of infected cells at the time of delivery as well as throughout the first nine months of life by the techniques outlined above. In addition, we will determine the origin of any infected cells by HLA typing as demonstrated above to explore the potential for transplacental egress of maternal cells into the fetal circulation as a mechanism of in utero transmission of infection. Finally, we will follow the level of proviral burden within the newborn to determine its correlation with subsequent disease progression. If such a correlation is established, these techniques may be used as a means of early diagnosis of infection in the newborn.

15-40%的婴儿会通过母婴传播HIV-1 HIV-1血清阳性母亲。 目前还不清楚为什么其他一些人传播 艾滋病毒-1感染给他们的婴儿，而大多数人没有。 迄今为止的研究 表明有多种因素与母婴传播有关 包括血浆病毒血症、母体免疫应答、母体病毒性 表型，妊娠期间抗逆转录病毒药物的使用，以及 产科 对传播方式或风险因素知之甚少 与子宫内传播有关。 确定所发挥的作用 通过胎盘在母婴间传播HIV-1可能导致 制定预防经胎盘感染的战略， 胎儿 我们的假设是：（i）HIV-1病毒载量在 妊娠期高血浆病毒血症母亲的胎盘 导致更高的传播率;以及（ii）尽早消除 新生儿PBMC中的HIV-1感染细胞导致长期的 无症状的幸存者，而不这样做的结果在早期 艾滋病的表现。 在这项申请中，我们建议（i）研究 妊娠期间PBMC/血浆病毒负荷与 分娩时绒毛膜羊膜层胎盘的病毒负荷;以及 (ii)在分娩时检查新生儿的病毒负荷， 在生命的头六个月，与随后的 HIV-1相关疾病的临床进展。 1. 测定母体PBMC和胎盘组织中的病毒负荷。 我们将分析以下中的病毒负荷：（i）在治疗期间的循环母体PBMC。 通过测定携带前病毒DNA的细胞的百分比， 原位DNA-PCR和血浆定量支链DNA病毒负荷 信号放大 此外，我们将确定相对 通过检测HIV-1来检测这些感染细胞的转录活性 通过逆转录酶原位PCR检测特异性RNA（剪接和未剪接）， 原位杂交和支链DNA扩增。 同样地， (ii)我们将分析胎盘组织内的病毒负荷， 相应的母亲结合组织学分型内 各种胎盘层，特别是在绒毛膜羊膜。 最后我们 将通过以下方式确定受感染细胞的来源（母体与胎儿）： 通过原位DNA PCR对感染细胞进行HLA- DQA和HLA-DRB 1抗原。 2. 新生儿PBMC中与疾病相关的病毒负荷测定 发展 我们将分析脐带血，血浆以及循环 来自新生儿的PBMC，以确定前病毒负荷和转录 感染细胞在递送时以及整个递送过程中的活性 前九个月的生活通过上述技术概述。 在 此外，我们将通过HLA分型确定任何感染细胞的来源 如上所述，为了探索经胎盘排出的可能性， 母体细胞进入胎儿循环作为一种机制， 感染的传播。 最后，我们将遵循前病毒水平 新生儿内的负担，以确定其与随后的 疾病进展。 如果建立了这种相关性， 技术可用作感染的早期诊断手段， 新生儿。