【摘要】： 目的:研究大腸桿菌刺激小鼠DC細(xì)胞對其表面分子CD40、B7-1、B7-2表達(dá)的影響。 方法:1、用不同濃度(2×107、2×106)大腸桿菌刺激小鼠DC細(xì)胞(DC2.4,2×105個/孔),LPS處理組作為陽性對照,PBS處理組作為陰性對照,在刺激4h及24h后收集細(xì)胞,提取RNA,采用RT-PCR法檢測DC細(xì)胞CD40 mRNA的表達(dá)。2、擴(kuò)大培養(yǎng)(DC細(xì)胞為1×106個/孔,大腸桿菌及LPS亦相應(yīng)擴(kuò)大5倍),感染4h及24h后收集細(xì)胞,用流式細(xì)胞術(shù)檢測其細(xì)胞表面分子CD40、B7-1、B7-2的表達(dá)。 結(jié)果:1、與陰性對照組比較,小鼠DC細(xì)胞在大腸桿菌刺激后,其表面CD40分子顯著增加,兩組比較有統(tǒng)計學(xué)意義(均P 0. 05)。其中,刺激4h增加水平低于刺激24h[(6714.5±1367.74)copies/μl vs (13105.0±801.06)copies/μl;(10101.0±797.69)copies/μl vs (15785.0±676.23)copies/μl],兩組比較有顯著統(tǒng)計學(xué)意義(均P 0. 01) ,較低濃度(1×107)刺激增加水平高于較高濃度刺激(1×108)([10101.0±797.69)copies/μl v(s6714.5±1367.74)copies/μl;(15785.0±676.23)copies/μl vs (13105.0±801.06)copies/μl],兩組比較有顯著統(tǒng)計學(xué)意義(均P 0. 01)。2、用大腸桿菌刺激小鼠DC細(xì)胞,與PBS陰性對照和LPS陽性對照比較,其表面分子B7-1、B7-2均無明顯變化,無統(tǒng)計學(xué)意義。 結(jié)論:1、培養(yǎng)的小鼠DC細(xì)胞有CD40分子表達(dá),大腸桿菌刺激后表達(dá)上調(diào),其上調(diào)程度與刺激時間成正相關(guān),與刺激濃度成負(fù)相關(guān),初步證明Th細(xì)胞極化受不同抗原負(fù)載量的影響。2、培養(yǎng)的小鼠DC細(xì)胞大量表達(dá)B7-1、B7-2分子,大腸桿菌刺激后表達(dá)未見明顯變化。
[Abstract]:Objective: to study the effect of Escherichia coli on the expression of CD40,B7-1,B7-2 in mouse DC cells. Methods: 1. Mouse DC cells were stimulated with different concentrations of E. coli (2 脳 107,2 脳 106) (DC2.4,2 脳 10 ~ 5 / well), LPS treatment group as positive control and PBS treatment group as negative control). The cells were collected after stimulation for 4 h and 24 h. RNA, was extracted to detect the expression of CD40 mRNA in DC cells by RT-PCR assay. 2, expanded culture (DC cells were 1 脳 10 ~ 6 / well, Escherichia coli and LPS were also expanded 5 times), and cells were collected 4 h and 24 h after infection. The expression of CD40,B7-1,B7-2 on the cell surface was detected by flow cytometry. Results: 1. Compared with the negative control group, the surface CD40 molecules of mouse DC cells stimulated by E. coli increased significantly, and there was significant difference between the two groups (all P 0. 0). ) Among them, the increase level of stimulation for 4 h was lower than that of stimulation for 24 h [(6714.5 鹵1367.74) copies/ 渭 l vs (13105.0 鹵801.06) copies/ 渭 l; (10101.0 鹵797.69) copies/ 渭 l vs (15785.0 鹵676.23) copies/ 渭 l], and there was significant difference between the two groups (all P 0). 01), the increased level of lower concentration (1 脳 107) stimulation was significantly higher than that of higher concentration stimulation (1 脳 108) ([10101.0 鹵797.69) copies/ 渭 l v (s6714.5 鹵1367.74) copies/ 渭 l; (15785.0 鹵676.23) copies/ 渭 l vs (13105.0 鹵801.06) copies/ 渭 l]. 01). 2. Compared with PBS negative control and LPS positive control, the surface molecules B7 and B7 of DC cells stimulated by E. coli had no significant change, and there was no significant difference between B7 and B7. Conclusion: 1. The expression of CD40 molecule in cultured mouse DC cells is up-regulated after stimulation with Escherichia coli. The up-regulation degree is positively correlated with stimulation time and negatively correlated with stimulation concentration. It is preliminarily proved that the polarization of Th cells is affected by different antigen loading. 2, the expression of B7 鈮，

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