Th1-to Th2 shift of HSP65 responses and atherogenesis

描述（由申请人提供 由细胞内生物、肺炎衣原体、分枝杆菌引起的感染。和/或幽门螺杆菌，已被认为是动脉粥样硬化的共同危险因素，但它们在疾病进展中的确切作用仍然存在争议。 我们建议描述感染会加速的动脉粥样硬化的免疫学变化。 1 型辅助性 T 淋巴细胞 (Thl-) 免疫激活局部巨噬细胞 (MQ)，杀死细胞内细菌，还可能损伤内皮组织，从而可能在早期引发病变。 先前的研究表明，脾脏前列腺素 E2 释放 MQ (PGE2-MQ) 水平随着动脉粥样硬化和感染的进展而增加。 由于 PGE2 是 Th1 至 Th2 免疫转变的强大诱导剂， PGE2-MQ 可能对动脉粥样硬化慢性阶段的发病机制做出重大贡献。在此。就此而言，分枝杆菌 65kDa 热休克蛋白 (HSP65) 受到了广泛关注，它是一种与其他细菌和哺乳动物 HSP 具有交叉反应性的免疫显性抗原。 Th1 到 Th2 的转变产生针对 HSP65 的抗体，该抗体可能通过抗原拟态攻击动脉。尽管Th1细胞的发育介导了对结核病的抵抗力，但目前尚不清楚HSP65特异性Th1反应是否也是促动脉粥样硬化的。 我们的目标是了解 HSP65 特异性 Th1 和 Th2 反应各自的致动脉粥样硬化作用以及转变的机制。我们将使用用 HSP65 或含有 HSP65 的热灭活 (HK) 牛分枝杆菌 BCG 免疫的高胆固醇血症载脂蛋白 E 敲除 (apoE-KO) 小鼠和野生型 (WT) 对照。 我们假设 HSP65 特异性 Th2 反应将增强 apoE-KO 小鼠的动脉粥样硬化病变发展。 我们将确定用 HSP65 和几丁质（一种 Th1 佐剂）或明矾（一种 Th2 佐剂）进行免疫是否会对 apoE-KO 小鼠中的动脉粥样硬化病变发展产生影响。我们将进一步确定HSP65特异性Th1细胞或Th2细胞的过继转移是否会对apoE-KO受体中的动脉粥样硬化病变发展产生影响。 用 89Sr 治疗小鼠会破坏骨髓中的 PGE2-MQ 前体并抑制脾脏 PGE2-MG 的形成。 我们假设这也将导致 Th1 反应的保留，而不转变为 Th2 反应。用89Sr治疗的小鼠将接受HK-BCG免疫以确定对HSP65反应的影响。 最后，我们将确定输注来自 HK-BCG 治疗的 WT 供体的 fit-1 骨髓细胞是否会恢复 89Sr 治疗的 WT 受者中的 Th1 到 Th2 转变。

DESCRIPTION (provided by applicant Infections caused by the intracellular organisms, Chlamydia pneumoniae, Mycobacterium sp. and/or Helicobacter pylori, have been implicated as co-risk factors in atherosclerosis, but their exact roles in disease progression remain controversial. We propose to characterize the immunological shifts in atherosclerosis that would be accelerated by the infections. Type 1 helper T lymphocyte- (Thl-) immunity activates local macrophages (MQ) that kill the intracellular bacteria and also potentially damage endothelial tissue, which could initiate lesions at the early stages. Previous studies suggest that splenic prostaglandin E2-releasing MQ (PGE2-MQ) levels are increased with the progression of atherosclerosis and in infections. Since PGE2 is a powerful inducer of the Thl to Th2 immune shift, PGE2-MQ could make a major contribution to the pathogenesis of chronic stages of atherosclerosis. In this. regard, much attention has been directed to mycobacterial 65kDa-heat shock protein (HSP65), an immunodominant antigen having cross-reactivity with other bacterial and mammalian HSPs. The Thl-to-Th2 shifts generate antibodies against HSP65 that potentially attack arteries through antigenic mimicry. Although the development of the Thl cells mediates resistance to tuberculosis, it remains unclear whether HSP65-specific Thl responses are also pro-atherogenic. Our goals are to understand the respective atherogenic roles of HSP65-specific Thl and Th2 responses as well as the mechanism of the shifts. We will employ hypercholesterolemic apolipoprotein E-knockout (apoE-KO) mice and wild type (WT) controls immunized with HSP65 or heat-killed (HK) M. bovis BCG containing HSP65. We hypothesize that HSP65-specific Th2 responses will enhance atherogenic lesion development in apoE-KO mice. We will determine if immunization with HSP65 and chitin, a Thl adjuvant, or alum, a Th2 adjuvant, will have an effect on atherogenic lesion development in apoE-KO mice. We will further determine if adoptive transfer of HSP65- specific Thl cells or Th2 cells will have an effect on atherogenic lesion development in apoE-KO recipients. Treatment of mice with 89Sr destroys PGE2-MQ precursors in the bone marrow and suppresses the formation of splenic PGE2-MG. We hypothesize that this will also result in retention of the Thl responses without a shift to a Th2 response. Mice treated with 89Srwill receive HK-BCG immunization to determine the effect on response to HSP65. Finally, we will determine if transfusion of fit-1 +marrow cells from HK-BCG treated WT donors will restore the Thl-to-Th2 shifts in 89Sr-treated WT recipients.