T LYMPHOCYTE SUBSETS AND HOST DEFENSE AGAINST P CARINII

描述 该项目的长期目标是确定主机防御 保护宿主免受肺孢子虫感染的重要机制 卡里尼。以前的工作已经证明了CD4T的关键作用 宿主的淋巴细胞防御这种感染，这可能解释了为什么P. 卡里尼肺炎是HIV感染的常见并发症。然而， CD4T淋巴细胞介导宿主的确切机制 对卡氏肺孢子虫感染的敏感性尚不清楚。此应用程序 建议研究T淋巴细胞亚群(Th1/Th2)在宿主中的作用 对这种感染的反应。初步数据显示，P. 正常小鼠的卡氏肺吸虫感染与 肺门淋巴结细胞中细胞因子图谱的出现与 Th1淋巴细胞。这个项目将检验这个实验假设 宿主对卡氏肺孢子虫感染的防御需要早期世代 特异性Th1 T淋巴细胞对病原体的最佳清除 肺组织。特定目标1将与卡氏肺孢子虫的清除相关 BALB/c小鼠体内出现Th1和Th2细胞的感染 连续间隔(3天至8周)肺淋巴结和肺实质 接种后。将使用定量RT鉴定Th1/Th2细胞 细胞因子(干扰素-γ、白介素2、白介素4、白介素5)的聚合酶链式反应和细胞因子的酶联免疫吸附试验 体外生产。特定目标2将确认Th1的保护作用 输注卡氏肺孢子虫特异性Th1和Th2淋巴细胞的研究 在免疫低下的SCID小鼠接种前体外扩增 卡氏肺孢子虫。4-8周后，动物将被处死并进行检测 卡氏肺孢子虫感染强度。具体目标3将两极分化 转基因小鼠体内对Th1或Th2模式的免疫应答 用腺病毒将干扰素-γ或IL-4基因导入BALB/c小鼠的肺内 向量。然后，小鼠将被接种卡氏肺孢子虫和 用于清除感染的化验。

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.