Total lung gene expression data of Pneumocystis-infected wildtype and IFN-gamma knockout mice.. Mus musculus

Pulmonary hypertension (PH) is a disease of diverse etiology. While primary PH can develop in the absence of prior disease, PH more commonly develops in conjunction with other pulmonary pathologies. We previously reported a mouse model in which PH occurs as a sequelae of Pneumocystis infection in the context of transient CD4 depletion. Here, we demonstrate that instead of the expected Th2 pathways, the Th1 cytokine IFN-γ was essential for the development of PH, as wild type mice developed PH, but not IFN-γ knockout mice. Because gene expression analysis showed few strain differences that were not immune function related, we focused on those responses as potential pathologic mechanisms. While there were several differences in cellular and cytokine response that warrant further examination, we focused on three important aspects. First, if CD4 cells were continuously depleted, but the infection was limited by antibiotic treatment, then PH did not occur, confirming that CD4 T-cells are required for PH development. Second, although CD8 T-cells are implicated in the pathology of unabated Pneumocystis pneumonia, they did not have a role in the onset of PH. Finally, although there are differences in the amounts of the pulmonary immune cells, differences existed in phenotypes of immune cells that correlated with PH, such as elevated CD204 expression in lung CD11c+ cells. Overall design: Two groups of BALB/c mice (3 per group) were infected i.t. with 10e7 Pneumocystis; one of those groups also received 4 injections of CD4 T-cell depleting antibodies beginning 3 days prior to infection and ending 7 days after infection. A third group was IFN-gamma knockout mice infected with Pneumocystis and depleted of CD4 cells in the same way. A fourth group of control non-treated BALB/c mice were also used. AT 38 days post infection, lung tissues were taken, and RNA was extracted to allow for differential gene expression analysis

肺动脉高压（Pulmonary hypertension, PH）是一类病因多样的疾病。原发性肺动脉高压可在无基础疾病的情况下发生，但肺动脉高压更常继发于其他肺部病理改变。我们此前曾报道一种小鼠模型，该模型中肺动脉高压可作为一过性CD4耗竭背景下肺孢子菌感染的后遗症出现。本研究证实，肺动脉高压的发生并非依赖预期的Th2通路，而是依赖Th1型细胞因子干扰素-γ（IFN-γ）：野生型小鼠可出现肺动脉高压，而IFN-γ基因敲除小鼠则不会。由于基因表达分析显示，非免疫功能相关的品系差异极少，因此我们将研究聚焦于此类应答作为潜在的病理机制。尽管在细胞与细胞因子应答中存在多项值得进一步探究的差异，但我们重点关注了三个关键方面：其一，若持续耗竭CD4阳性T细胞，但通过抗生素治疗限制肺孢子菌感染，则不会发生肺动脉高压，这证实CD4阳性T细胞是肺动脉高压发生的必需条件；其二，尽管CD8阳性T细胞与未控制的肺孢子菌肺炎的病理损伤相关，但它们并未参与肺动脉高压的发病过程；其三，尽管肺部免疫细胞的数量存在差异，但免疫细胞的表型改变与肺动脉高压的发生密切相关，例如肺部CD11c阳性细胞中CD204受体表达水平升高。实验总体设计：将两组BALB/c小鼠（每组3只）经气管内（intratracheal, i.t.）感染1×10^7个肺孢子菌；其中一组在感染前3天至感染后7天期间，共接受4次CD4阳性T细胞耗竭抗体注射。第三组为IFN-γ基因敲除小鼠，以相同方式感染肺孢子菌并耗竭CD4阳性T细胞。同时设置第四组未接受任何处理的BALB/c小鼠作为对照。于感染后38天采集肺组织，提取RNA以开展差异基因表达分析。