T LYMPHOCYTE SUBSETS AND HOST DEFENSE AGAINST P CARINII

描述 本项目的长期目标是确定宿主防御 保护宿主免受肺孢子虫感染的重要机制 carinii。以前的工作已经证明了CD 4 + T细胞的关键作用， 淋巴细胞参与了宿主的防御，这可能解释了为什么P. 卡氏肺炎是艾滋病毒感染的常见并发症。但 CD 4 + T淋巴细胞介导宿主免疫的精确机制 对卡氏肺孢子虫感染敏感性是未知的。本申请 目的探讨T淋巴细胞亚群（Th 1/Th 2）在宿主免疫应答中的作用 应对这种感染。初步数据表明，清除P。 正常小鼠的卡氏体感染在时间上与 肺门淋巴结细胞中细胞因子谱的出现与 Th 1淋巴细胞。这个项目将测试实验假设， 宿主对卡氏肺孢子虫感染的防御需要早期世代 特异性Th 1 T淋巴细胞的最佳清除病原体从 肺组织特异性目标1将与卡氏肺孢子虫的清除相关 感染BALB/c小鼠，Th 1和Th 2淋巴细胞出现， 连续间隔（3天至8周）的肺淋巴结和实质 接种后。将使用定量RT鉴定Th 1/Th 2细胞 细胞因子mRNA（IFN-γ、IL-2、IL-4、IL-5）PCR和细胞因子ELISA 体外生产。具体目标2将确认Th 1的保护作用 通过使用卡氏肺孢子虫特异性Th 1和Th 2淋巴细胞的免疫印迹法检测淋巴细胞 在体外扩增到免疫功能低下的SCID小鼠中， P. carinii。4-8周后，处死动物，并测定 卡氏肺孢子虫感染强度。第3章将被淘汰 通过转移鼠淋巴细胞在体内对Th 1或Th 2模式宿主免疫应答 使用腺病毒介导的IFN-γ或IL-4基因进入BALB/c小鼠的肺中 vector.然后将小鼠接种卡氏肺孢子虫生物体， 测定感染清除率。

DESCRIPTION The long-term objective of this project is to identify host defense mechanisms important in protecting the host from infection with Pneumocystis carinii. Previous work has demonstrated a critical role for the CD4+ T lymphocyte in host defense against this infection, which may explain why P. carinii pneumonia is a common complication of HIV infection. However, the precise mechanisms through which CD4+ T lymphocytes mediate host susceptibility to P. carinii infection are unknown. This application proposes to investigate the role of T lymphocyte subsets (Th1/Th2) in host responses to this infection. Preliminary data show that clearance of P. carinii infection in normal mice is temporally associated with the appearance of a cytokine profile in hilar lymph node cells consistent with Th1 lymphocytes. This project will test the experimental hypothesis that host defense against infection with P. carinii requires the early generation of specific Th1 T lymphocytes for optimal clearance of the pathogen from lung tissue. Specific Aim 1 will correlate clearance of P. carinii infection in BALB/c mice with the appearance of Th1 and Th2 lymphocytes in lung lymph nodes and parenchyma at serial intervals (3 days to 8 weeks) after inoculation. Th1/Th2 cells will be identified using quantitative RT PCR for cytokine mRNA (IFN-gamma, IL-2, IL-4, IL-5) and ELISA for cytokine production in vitro. Specific Aim 2 will confirm a protective role for Th1 lymphocytes by transfusing P. carinii-specific Th1 and Th2 lymphocytes expanded in vitro into immunocompromised scid mice prior to inoculation with P. carinii. After 4-8 weeks, the animals will be sacrificed and assayed for intensity of infection with P. carinii. Specific Aim 3 will polarize the host immune response to a Th1 or Th2 pattern in vivo by transferring murine IFN-gamma or IL-4 genes into the lungs of BALB/c mice using an adenoviral vector. The mice will then be inoculated with P. carinii organisms and assayed for clearance of infection.