特异性脱氧核酶对小鼠呼吸道合胞病毒感染的抑制作用

Special deoxyribozyme suppresses respiratory syncytial virus infection to mice

目的研究特异性抑制呼吸道合胞病毒(respiratory syncytial virus,RSV)N基因的脱氧核酶DZ1133在小鼠体内对病毒复制和气道炎症的影响。方法RSV感染BALB/c小鼠滴鼻给予DZ1133及其变异体、反义寡核苷酸AS1133,空斑形成实验检测肺组织病毒滴度,RT-PCR检测病毒mRNA表达,支气管肺泡灌洗液白细胞计数,ELISA检测TNF-α、IL-12、IFN-γ和IL-10水平,肺组织病理学分析炎症情况。结果0.2、0.4mg和0.8mgDZ1133治疗组小鼠肺组织病毒滴度分别为(2.75±0.21)×105、(1.86±0.20)×105PFU/g和(1.02±0.22)×105PFU/g,与感染对照组小鼠(7.94±0.42)×105PFU/g比较明显下降(P<0.01),上述各剂量治疗组小鼠肺组织病毒mRNA表达与感染对照组比较分别下降30.51%、47.38%(P<0.05)和53.97%(P<0.01)。0.4mgDZ1133治疗降低RSV感染小鼠支气管肺泡灌洗液中白细胞总数,改善肺组织病理学损伤(P<0.05),对TNF-α、IL-12、IFN-γ和IL-10水平无显著性影响(P>0.05)。结论特异性脱氧核酶DZ1133在小鼠体内有效抑制RSV复制、减轻气道炎症,是有效的抗RSV途径。

Objective To investigate the effects of special deoxyribozyme DZ1133 targeting N gene of respiratory syncytial virus （RSV） on viral replication and airway inflammation in mice. Methods RSV infected BALB/c mice were nasally dripped with DZ1133, mutant DZ1133 and antisense oligonucleotide AS1133 respectively. Pulmonary viral titers were detected by plaque forming experiment. Pulmonary RSV N mRNA expression was assayed by RT-PCR. Leukocytes and the subgroup cells in bronchoalveolar lavage fluid （BALF） were counted, and the concentration of cytokines such as TNF-α, IL-12, IFN-γ and IL-10 in BALF were assayed by ELISA. Pulmonary histopathology was performed to observe the inflammation of airway. Results Pulmonary titers of 0. 2, 0.4 and0.8 mg DZl133 treated mice were （2.75±0.21）×10^5、（1.86±0.20）×10^5PFU/g and （1.02±0.22）×10^5PFU/g respectively, which were significantly decreased as compared with those of infected control mice [（7.94±0.42）×10^5PFU/g , P 〈0.01 ]. Meanwhile the pulmonary viral mRNA of 0.2, 0.4 mg and 0.8 mg DZ1133 treated mice were inhibited by 30.51% , 47.38% （P 〈 0. 05 ） and 53.97% （P 〈 0.01 ） respectively compared with infected control mice. The inhibitory effects of DZ1133 on viral titer and mRNA expression were much stronger than AS1133. The treatment of 0.4 mg mutant DZ1133 had no significant inhibitory effect on RSV. In 0.4 mg DZ1133 treated group, total number of leukocytes in BALF was decreased dramatically and pulmonary histology was significantly improved compared with infected control （ P 〈 0.05 ）. But the treatment of 0.4 mg DZ1133 did not affect the productions of TNF-α, IL-12, IFN-γand IL-10 in BALF of RSV infected mice （P 〉0.05）. Conclusion Special deoxyribozyme DZ1133 targeting RSV N gene effectively inhibits viral replication and reduces airway inflammation. DZ1133 is a potential therapeutic agent against RSV infection in vivo.