M2型巨噬细胞在梅毒血清固定形成中的作用和机制

Sysphilis serofast reaction patients survive living Treponema pallidum that can cause relapse and reinfection, the specific mechanism of which is still unclear. We have previously found that there is one Treponema pallidum subtype for serofast sysphilis serofast reaction, which is closely related to syphilis serofast reaction. Meanwhile, there is a Th1/Th2 lymphocytes balance drift toward Th2 lymphocyte in these sysphilis serofast reaction patients. We hypothesize that Th2 cellular immunity plays a role in sysphilis serofast reaction prognosis through macrophage polarization towards M2 macrophage. To confirm this hypothesis, we will conduct following studies: 1）Verifying the macrophage polarization state in sysphilis serofast reaction patients. 2) Elucidating the effect and functions of the Treponema pallidum serofast subtypes upon the macrophage polarization. 3) Exploring whether the targeted over expression of IL-2 has an impact on the phenotype and functions of the alternatively activated macrophage (M2), further confirming cytokines negatively regulated by Stat 3 have a feedback regulation on Stat 3 signal pathway. 4) Conducting animal studies to confirm that macrophage polarization plays a role in occurrence, progressing and prognosis after infected with serofast reaction Treponema pallidum subtype. 5) Conducting animal studies to explore whether the targeting macrophage using recombinant adenovirus carrying the IL-2 gene has an effect on preventing and curing sysphilis. This study will contribute to elucidating the mechanism of syphilis serofast reaction and explaining the pathogenesis of the treponema pallidum serofast subtypes, further paving a new way for syphilis curing.

梅毒血清固定患者体内残存有梅毒螺旋体（Tp），可致复发和传染，其发病机制未明。我们研究发现：致梅毒血清固定亚型的Tp与其发生密切相关；且此类患者存在Th1/Th2动态平衡向Th2方向漂移。猜测Th2 型细胞免疫反应可通过巨噬细胞向M2型极化影响梅毒血清固定的发生。为验证假说，拟开展以下研究：1）明确梅毒血清固定患者巨噬细胞极化状态；2）阐明致梅毒血清固定亚型Tp对巨噬细胞的极化作用及功能的影响；3）探讨靶向过表达IL-12对M2型巨噬细胞表型及功能的影响，并证明Stat 3负性调控表达的细胞因子对Stat 3信号途径存在负反馈调节；4）采用动物模型阐明致梅毒血清固定亚型Tp感染机体后，梅毒发生、发展、转归过程与巨噬细胞极化的关系；5）动物模型探讨携IL-12基因的巨噬细胞重组腺病毒对梅毒血清固定发生的预防和治疗效果。本研究将有助于揭示梅毒血清固定的形成机制，并为其防治提供新思路。

梅毒血清固定的发病机制未明。我们研究发现梅毒固定亚型患者存在Th1/Th2 动态平衡向Th2 方向漂移。动物实验验证了不同株型梅毒螺旋体感染后临床状症不同。采用体外细胞培养实验明确了梅毒螺旋体感染初期巨噬细胞向M1发展，在此过程中激活了Akt, mTOR 和NF-κB通路。而随着培养时间的延长，M2巨噬细胞的相关因子表达增加。此外我们也从体外和动物实验证实了梅毒早期的炎症和巨噬细胞NLRP3炎症复合体的活化密切相关。.我们拟建立兔感染建立动物模型，采用携IL-12 基因的靶向巨噬细胞重组腺病毒在预防梅毒血清固定的发生、治疗梅毒的效果，因目前检测兔蛋白表达的抗体较少，部份实验无法完成。因此，课题采用常规的青霉素治疗方案观察不同株型梅毒螺旋体作用后皮损变化的差异，以及治疗和未治疗中感染兔巨噬细胞的功能变化，探讨青霉素治疗对于巨噬细胞功能和梅毒炎的影响，发现青霉素轻微调整了梅毒的炎症进程。.此外在体外实验中，我们的观察时间是48小时，到48小时细胞的状态不佳，因此我们目前仅观察梅毒螺旋体作用于巨噬细胞后的极化情况及其功能的变化。后续我们将选可以培养更长时间的巨噬细胞系，进一步明确不同株型梅毒螺旋体作用致梅毒血清固定形成的机制。