Zhu Cuiming, Yu Minjun, Gao Shunli, Zeng Yanhua, You Xiaoxing, Wu Yimou
Department of Microbiology and Immunology, University of South China, Hengyang 421001, China.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2013 Jun;29(6):585-8.
To investigate the immune responses and immune protections of a DNA vaccine constructed by fusing Mycoplasma pneumoniae (M. pneumoniae) p1 gene car boxy terminal region (p1c gene) with interleukin-2 (IL-2) gene.
BALB/c mice were immunized by intranasal inoculation of P1C-IL-2 fusion DNA vaccine. Levels of serum IgG, IgG isotypes, BAL fluids IgA, IFN-γ and IL-4 were detected by ELISA. We established the mouse models infected with M. pneumoniae, and then observed the histopathological changes in lungs and counted colonies in bronchoalveolar lavage fluid (BALF) after challenged intranasally with M. pneumoniae.
Serum total IgG, IgG1 and IgG2a isotypes, levels of IFN-γ and IL-4 in BALF increased significantly in the group inoculated with P1C-IL-2 fusion DNA vaccine as compared with the one with P1C DNA vaccine (P<0.05), while there was no significant difference in BALF IgA between the two groups (P>0.05). The lung tissue inflammation was aggravated and the histopathologic score (HPS) of P1C-IL-2 DNA vaccine immunized mice significantly increased as compared with those in P1C DNA vaccine immunized mice at 1, 3, 6 d after challenged intranasally with M. pneumoniae (P<0.05). The P1C-IL-2 fusion DNA vaccine did not show significant difference from P1C DNA vaccine in the detectable number of M. pneumoniae strain in BALF(P>0.05).
IL-2 can enhance the systemic immune responses of P1C DNA vaccine, but it also can develop a severe histopathological change in early days after infection of M. pneumoniae.
研究将肺炎支原体（M. pneumoniae）p1基因羧基末端区域（p1c基因）与白细胞介素-2（IL-2）基因融合构建的DNA疫苗的免疫反应和免疫保护作用。
通过鼻内接种P1C-IL-2融合DNA疫苗免疫BALB/c小鼠。采用酶联免疫吸附测定法（ELISA）检测血清IgG、IgG亚型、支气管肺泡灌洗液（BALF）中的IgA、干扰素-γ（IFN-γ）和白细胞介素-4（IL-4）水平。建立肺炎支原体感染小鼠模型，然后观察鼻内接种肺炎支原体后肺组织的组织病理学变化，并对BALF中的菌落进行计数。
与接种P1C DNA疫苗的组相比，接种P1C-IL-2融合DNA疫苗的组血清总IgG、IgG1和IgG2a亚型、BALF中IFN-γ和IL-4水平显著升高（P<0.05），而两组BALF中IgA水平差异无统计学意义（P>0.05）。鼻内接种肺炎支原体后1、3、6 d，与接种P1C DNA疫苗的小鼠相比，接种P1C-IL-2 DNA疫苗的小鼠肺组织炎症加重，组织病理学评分（HPS）显著升高（P<0.05）。P1C-IL-2融合DNA疫苗与P1C DNA疫苗在BALF中肺炎支原体菌株可检测数量上差异无统计学意义（P>0.05）。
IL-2可增强P1C DNA疫苗的全身免疫反应，但也可在肺炎支原体感染早期引发严重的组织病理学变化。
