Placental Immunopathology in the FIV-infected Cat Model

描述（由申请人提供）：子宫内传播是儿童艾滋病毒感染的重要来源，感染艾滋病毒的妇女流产率较高。该病毒经胎盘传播或扰乱妊娠的机制尚不清楚。胎盘免疫调节剂参与正常妊娠的调节。成功怀孕通常偏向于th2介导的免疫反应，Th1细胞因子的表达必须被抑制。滋养细胞和蜕膜白细胞表达调节胎盘免疫的免疫调节剂。滋养细胞可以感染艾滋病毒。胎盘中表达的一些免疫调节剂增强了HIV的表达，并且HIV感染可以改变滋养层细胞因子的谱。因此，胎盘免疫失调可能发生在HIV感染期间，可能导致HIV垂直转移和胎儿损伤。感染fiv的猫是HIV垂直感染的模型，垂直感染导致怀孕受损。初步数据表明，感染fiv的皇后胎盘Th1细胞因子表达增加。这个项目的目的是在细胞水平上评估胎盘免疫病理，在妊娠早期和晚期，开始了解慢病毒感染如何损害妊娠的机制。本项目的具体目的是：1)确定FIV感染是否诱导滋养细胞的免疫病理。采用激光捕获显微解剖（LCM）捕获滋养层细胞，检测具有代表性的Th1和Th2细胞因子、趋化因子受体CXCR4 （FIV的辅助受体）、其配体SDF和FIV在胎盘滋养层细胞中的表达，然后采用TaqMan实时PCR评估基因表达。2)确定FIV感染是否诱导胎盘细胞毒性。将使用免疫组织化学对蜕膜白细胞群进行量化，并在LCM和实时PCR之后确定这些细胞中的细胞因子谱。病毒感染对滋养细胞凋亡的影响将采用TUNEL试验进行检测。3)评价皇后外周血和子宫循环的免疫变化是否预示着宫内妊娠。流式细胞术将用于定量白细胞群；实时荧光定量PCR检测细胞因子表达；测定血清中Th1:Th2细胞因子比值。总的来说，从本研究中获得的数据可以确定导致FIV经胎盘传播和妊娠受损的胎盘免疫因素，并确定外周循环中妊娠窘迫的免疫学证据。该项目的长期目标是为基于免疫的干预策略提供智力基础，以最大限度地减少病毒诱导的胎盘免疫病理和生殖失败。

DESCRIPTION (provided by applicant): Transmission in utero is an important source of pediatric HIV infections, and miscarriages occur at an elevated rate in HIV-infected women. The mechanism for transplacental transmission or perturbation of pregnancy by the virus is unknown. Placental immunomodulators are involved in the regulation of normal pregnancy. Successful pregnancy typically is biased toward a Th2-mediated immune response, and Th1 cytokine expression must by suppressed. Trophoblastic cells and decidual leukocytes express immunomodulators that regulate placental immunology. Trophoblasts can be infected with HIV. HIV expression is augmented by some immunomodulators that are expressed in the placenta, and HIV infections can alter the profile of trophoblastic cytokines. Thus, dysregulation of placental immunology probably occurs during HIV infections, possibly contributing to HIV vertical transfer and fetal damage. The FIV-infected cat is a model for HIV vertical infections, with vertical infection resulting in compromised pregnancy. Preliminary data indicate increased expression of placental Th1 cytokines in FIV-infected queens. The purpose of this project is to evaluate placental immunopathology at the cellular level, at early and late gestation, to begin to understand mechanistically how lentiviral infection compromises pregnancy. The specific aims of this project are to: 1) Determine whether FIV infection induces immunopathology in trophoblasts. The expression of representative Th1 and Th2 cytokines, the chemokine receptor CXCR4 (a coreceptor for FIV), its ligand SDF, and FIV in placental trophoblasts will be determined using laser capture microdissection (LCM) to capture trophoblasts, followed by TaqMan real time PCR to assess expression of the genes. 2) To determine whether FIV infection induces placental cytotoxicity. Decidual leukocyte populations will be quantified using immunohistochemistry, and cytokine profiles in these cells will be determined, following LCM and real time PCR. The effect of viral infection on apoptosis of trophoblasts will be examined using the TUNEL assay. 3) To evaluate whether immunological changes in the peripheral and uterine circulation of queens are predictive of compromised pregnancy. Flow cytometry will be done to quantify leukocyte populations; cytokine expression in these cells will be quantified by real time PCR; and Th1:Th2 cytokine ratios in serum will be measured. Collectively, the data obtained from this study may identify placental immunological factors that result in FIV transplacental transmission and compromised pregnancy and identify immunological evidence of pregnancy distress in the peripheral circulation. The long-term goal of this project is to provide the intellectual basis for immune-based intervention strategies to minimize virus-induced placental immunopathology and reproductive failure.