Department of Spine Surgery, Daping Hospital, Research Institute of Surgery, Third Military Medical University, Chongqing, PR China.
Neuroimmunomodulation. 2013;20(2):87-98. doi: 10.1159/000345522. Epub 2012 Dec 19.
Immune cells are key mediators of secondary damage following spinal cord injury (SCI), and dendritic cell (DC)-based vaccines have received considerable interest for treatment of SCI. We previously showed that vaccination with DCs pulsed with homogenate proteins of the spinal cord (hpDCs) promotes functional recovery from SCI in mice. However, the underlying molecular mechanisms remain unclear. Here, changes of neurotrophins, cytokines and T cells at the site of SCI in mice after vaccination with hpDCs were investigated and correlated with recovery from SCI.
hpDCs, DCs (control) or PBS (control) were injected intraperitoneally into injured mouse spinal cords. Functional recovery of the spinal cord was measured weekly using the Basso Mouse Scale (BMS) and confirmed by histological and immunohistochemical analysis. Brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), interleukin-4 (IL-4) and interferon-γ (IFN-γ) levels in T cell culture supernatants and spinal cord tissues were determined by ELISA.
Eighty-four days after immunization, the BMS score of the hpDCs group (6.92 ± 0.20) was significantly higher than those of the DCs and PBS groups (p < 0.01). Meanwhile, the injury area and number of cysts in the hpDCs group decreased significantly compared with control groups. BDNF, NT-3, IL-4 and IFN-γ levels at the injured site as well as BDNF and NT-3 levels in the supernatant of cultured T cells from the hpDCs group were significantly higher than in control groups (p < 0.05).
These results reveal that vaccination with hpDCs can promote SCI repair potentially by upregulating BDNF, NT-3, IL-4 and IFN-γ at the injury site.
免疫细胞是脊髓损伤（SCI）后继发损伤的关键介质，基于树突状细胞（DC）的疫苗因其治疗 SCI 的潜力而受到广泛关注。我们之前的研究表明，用脊髓匀浆蛋白脉冲处理的 DC（hpDCs）疫苗接种可促进 SCI 后小鼠的功能恢复。然而，其潜在的分子机制尚不清楚。在此，研究了 hpDCs 疫苗接种后 SCI 小鼠损伤部位神经生长因子、细胞因子和 T 细胞的变化，并与 SCI 的恢复相关联。
将 hpDCs、DC（对照）或 PBS（对照）经腹腔注射到损伤的小鼠脊髓中。每周通过 Basso 小鼠量表（BMS）测量脊髓的功能恢复，并通过组织学和免疫组织化学分析进行确认。通过 ELISA 测定 T 细胞培养上清液和脊髓组织中脑源性神经营养因子（BDNF）、神经营养因子-3（NT-3）、白细胞介素-4（IL-4）和干扰素-γ（IFN-γ）的水平。
免疫后 84 天，hpDCs 组的 BMS 评分（6.92±0.20）明显高于 DCs 和 PBS 组（p<0.01）。同时，与对照组相比，hpDCs 组的损伤面积和囊泡数量明显减少。hpDCs 组损伤部位的 BDNF、NT-3、IL-4 和 IFN-γ水平以及 hpDCs 组培养 T 细胞上清液中的 BDNF 和 NT-3 水平均明显高于对照组（p<0.05）。
这些结果表明，hpDCs 疫苗接种可通过上调损伤部位的 BDNF、NT-3、IL-4 和 IFN-γ 来促进 SCI 修复。
