大蒜新素对MCMV感染小鼠转录因子T-bet和GATA-3基因表达的影响

The effects of allitridin on the expression of transcription factor T-bet/GATA-3 in mice infected by murine cytomegalovirus

目的探讨大蒜新素(即大蒜素注射液)对鼠巨细胞病毒(murinecytomegalovirus,MCMV)感染小鼠脾转录因子Tbet和GATA3基因表达的影响。方法20只BALBc小鼠被随机分成大蒜新素治疗组(10只)和安慰剂组(10只)。均在MCMVSmith株接种24h后分别用大蒜新素一般剂量(每天25mgkg)和等量生理盐水腹腔注射,每天1次,连续2周。另设正常对照组(10只)不接种病毒,仅用等量生理盐水治疗。用PFUml测定小鼠脾组织病毒滴度;用RTPCR方法检测小鼠脾转录因子TbetGATA3mRNA表达强度;用双抗体夹心ELISA法检测小鼠脾细胞培养上清细胞因子IFNγ和IL10表达水平。结果MCMV感染小鼠14d,TbetmRNA和IFNγ的表达基本下降至基线水平,而GATA3mRNA和IL10的表达显著增强;大蒜新素能诱导MCMV感染模型鼠转录因子TbetmRNA和IFNγ的表达显著增加(P<0.01),而转录因子GATA3mRNA和IL10的表达显著下降(P<0.01);同时显著降低小鼠脾组织匀浆中病毒滴度(P<0.01)。结论MCMV感染可导致TH1TH2类细胞因子表达失衡,主要表现为IFNγ表达明显降低和IL10表达明显增高;大蒜新素通过上调转录因子TbetmRNA的表达促进IFNγ的分泌,并下调转录因子GATA3mRNA的表达抑制IL10的分泌。

Objective To investigate the effects of allitridin on the expression of transcription factor T-bet/GATA-3 in mice infected by murine cytomegalovirus. Methods 20 BALB/c mice were randomly divided into allitridin treated group(n=10) and placebo controls group(n=10). Allitridin therapy group were given to mice via the intraperitoneal (i.p.) route once a day with general dosage (25mg/kg) at 24 hours after infected MCMV; placebo controls group were given with the same volume of 0.89% sodium chloride. Blank controls group (n=10), the same volume of 0.89% sodium chloride was injected. All experimental mice were sacrificed at 14 days i. p. The spleens were removed under aseptic conditions, and infectious virus was quantified by plaque assay. The expression levels of transcription factor T-bet/GATA-3 were measured by RT-PCR. The expression levels of IFN-γ and IL-10 in supernatant of spleen cell culture were measured by ELISA. Results MCMV infection markedly down-modulated the expression of IFN-γ and T-bet mRNA, significantly up-modulated the expression of IL-10 and GATA-3 mRNA. Allitridin induced an increased expression of transcription factor T-bet mRNA and IFN-γ significantly(P<0.01), decreased expression of transcription factor GATA-3 mRNA and IL-10 markedly (P<0.01). MCMV-infected mice treated with allitridin showed a significant (P<0.01) reduction in virus titers in the spleens compared to the untreated MCMV-infected mice. Conclusion MCMV infection can lead to disequilibrium of T_H1/T_H2 cytokine expression: the level of IFN-γ was significantly decreased and IL-10 overexpressed. Allitridin up-regulate the expression of T-bet mRNA and IFN-γ, and inhibit the expression of GATA-3 mRNA and IL-10 in MCMV infected mice, indicating a T_H1 dominant state which will enhance the specific cellular immune reactions against cytomegalovirus and be helpful for clearance of cytomegalovirus in host.