荊雪寧邱 波戰(zhàn)文翔武繼彪
黃芪多糖誘導(dǎo)的樹(shù)突狀細(xì)胞疫苗對(duì)S180荷瘤小鼠Th1/Th2類細(xì)胞因子的影響
荊雪寧1邱 波2戰(zhàn)文翔1武繼彪1
目的 探討黃芪多糖誘導(dǎo)成熟的樹(shù)突狀細(xì)胞(DC)腫瘤疫苗對(duì)S180荷瘤小鼠的抗腫瘤作用及作用機(jī)制。方法體外培養(yǎng)小鼠骨髓來(lái)源的DC,加入黃芪多糖誘導(dǎo)成熟,以S180腫瘤抗原致敏獲得DC腫瘤疫苗。建立S180荷瘤小鼠模型,分為模型組、環(huán)磷酰胺組、黃芪多糖組、細(xì)胞因子組,在荷瘤第5天和第10天分別給予相應(yīng)治療。荷瘤第12天摘取腫瘤組織、胸腺、脾臟稱質(zhì)量,計(jì)算抑瘤率、胸腺指數(shù)、脾臟指數(shù);ELISA法檢測(cè)小鼠血清白細(xì)胞介素(IL)-4、干擾素(IFN)-γ水平。結(jié)果黃芪多糖組、細(xì)胞因子組的抑瘤率高于環(huán)磷酰胺組(64.25%、64.10%vs 35.11%),胸腺指數(shù)高于環(huán)磷酰胺組(1.69±0.26、1.74±0.38 vs 1.45±0.22),脾臟指數(shù)高于環(huán)磷酰胺組(5.44±0.76、5.31± 0.81 vs 3.54±0.52),IL-4水平(ng/L)低于環(huán)磷酰胺組(15.66±2.57、14.72±4.84 vs 23.95±6.07),IFN-γ水平(ng/L)高于環(huán)磷酰胺組(16.54±3.71、17.20±2.03 vs 10.37±2.19),差異均有統(tǒng)計(jì)學(xué)意義。結(jié)論黃芪多糖誘導(dǎo)的DC疫苗可有效發(fā)揮抑瘤作用,其機(jī)制可能與提高荷瘤小鼠胸腺指數(shù)與脾臟指數(shù),調(diào)節(jié)細(xì)胞因子表達(dá),促進(jìn)Th1/Th2失衡向Th1細(xì)胞占優(yōu)勢(shì)的細(xì)胞免疫偏移,增強(qiáng)機(jī)體的抗腫瘤免疫功能有關(guān)。
黃芪多糖;樹(shù)突細(xì)胞;白細(xì)胞介素4;干擾素Ⅱ型;抑瘤率;胸腺指數(shù);脾臟指數(shù);Th1/Th2
黃芪多糖是中藥黃芪的主要活性成分之一,具有顯著的免疫調(diào)節(jié)和抗腫瘤作用。樹(shù)突狀細(xì)胞(dendritic cell,DC)是機(jī)體功能最強(qiáng)大的抗原遞呈細(xì)胞,捕獲抗原后可有效遞呈可溶性腫瘤抗原,激活靜息T細(xì)胞,在特異性抗腫瘤方面發(fā)揮重要作用?;贒C具有誘導(dǎo)初始免疫應(yīng)答、增強(qiáng)機(jī)體特異性抗腫瘤免疫反應(yīng)的能力,選擇DC作為載體制備腫瘤疫苗被認(rèn)為是最具潛力的腫瘤免疫治療手段[1]。黃芪多糖的抗腫瘤和免疫調(diào)節(jié)作用已在體內(nèi)外實(shí)驗(yàn)中得到證實(shí)[2],但是關(guān)于黃芪多糖對(duì)DC影響的研究較少。本研究以黃芪多糖代替腫瘤壞死因子-α(tumor necrosis factor,TNF-α)誘導(dǎo)小鼠來(lái)源的DC成熟,以S180腫瘤抗原致敏,制備DC腫瘤疫苗,通過(guò)對(duì)S180荷瘤小鼠進(jìn)行免疫治療,探討黃芪多糖誘導(dǎo)成熟的DC腫瘤疫苗的體內(nèi)抑瘤效果及機(jī)制,為開(kāi)拓中藥治療腫瘤的途徑提供實(shí)驗(yàn)依據(jù)。
1.1 材料
1.1.1 動(dòng)物和瘤株 雄性昆明種小鼠,6~8周齡,體質(zhì)量18~20 g。購(gòu)于山東大學(xué)實(shí)驗(yàn)動(dòng)物中心,動(dòng)物許可證號(hào)為SCXK(魯)20090001。小鼠肛門肉瘤細(xì)胞S180購(gòu)自南京凱基生物科技發(fā)展有限公司。
1.1.2 主要藥品和試劑 黃芪多糖,純度>98%,天津賽諾制藥有限公司生產(chǎn)。環(huán)磷酰胺,江蘇恒瑞醫(yī)藥公司產(chǎn)品。RPMI1640,Gibco公司生產(chǎn);胎牛血清,Hyclone公司生產(chǎn);小鼠淋巴細(xì)胞分離液購(gòu)自北京索寶來(lái)科技有限公司,Hanks液購(gòu)自南京凱基生物科技發(fā)展有限公司。重組粒細(xì)胞-巨噬細(xì)胞集落刺激因子(rmGM-CSF)、重組白細(xì)胞介素-4(rmIL-4)、重組TNF-α(rmTNF-α)購(gòu)自PeproTech公司,小鼠IL-4、干擾素(IFN)-γ ELISA試劑盒購(gòu)自RayBiotech公司。FITC標(biāo)記大鼠抗小鼠CD80、PE標(biāo)記大鼠抗小鼠CD86抗體購(gòu)自BD公司。
1.2 方法
1.2.1 DC腫瘤疫苗的制備 (1)小鼠骨髓單個(gè)核細(xì)胞的獲取。昆明種小鼠用頸椎脫位法處死,浸入75%乙醇浸泡10 min。無(wú)菌環(huán)境取雙側(cè)股骨、脛骨,剝離附著的肌肉軟組織,用無(wú)血清RPMI1640沖洗,剪開(kāi)骨兩端,用1 mL注射器抽取無(wú)血清RPMI1640,插入骨髓腔反復(fù)沖洗至紅色變淺。將收集的骨髓沖洗液以1 500 r/min離心10 min。以RPMI1640培養(yǎng)液重懸骨髓細(xì)胞,用淋巴細(xì)胞分離液密度梯度離心法獲得小鼠骨髓來(lái)源的單個(gè)核細(xì)胞。(2)DC的體外誘導(dǎo)與鑒定。用含10%胎牛血清的RPMI1640培養(yǎng)液將細(xì)胞濃度調(diào)至2×106/mL,加入細(xì)胞培養(yǎng)瓶,每孔6 mL,于37℃、5%CO2培養(yǎng)箱中培養(yǎng)。4 h后吸出懸浮細(xì)胞,留取貼壁細(xì)胞即為單核細(xì)胞。向培養(yǎng)瓶加入含rmGM-CSF 100 μg/L、rmIL-4 100 μg/L、10%胎牛血清的RPMI1640培養(yǎng)液6 mL,繼續(xù)培養(yǎng)。第2天、第4天行半量換液,第5天分別加入黃芪多糖100 mg/L和rm TNF-α 20 μg/L誘導(dǎo)成熟。第7天收集2種方法誘導(dǎo)的DC細(xì)胞,調(diào)細(xì)胞濃度為1×106/mL,向細(xì)胞中加入FITC標(biāo)記的CD80和PE標(biāo)記的CD86抗體,終濃度為5 mg/L。4℃避光保存30 min。用PBS洗滌2次,用流式細(xì)胞儀進(jìn)行檢測(cè)。(3)負(fù)載S180腫瘤全抗原的DC疫苗的制備。離心收集S180腹水瘤小鼠腹水中的S180細(xì)胞,調(diào)整細(xì)胞濃度為1× 108/mL,液氮反復(fù)凍融4次,制備成腫瘤完全抗原。各組DC培養(yǎng)的第8天,向培養(yǎng)體系加入S180腫瘤抗原0.2 mL,DC與腫瘤抗原的比例為1∶20(抗原的量按凍融前腫瘤細(xì)胞的量計(jì))。第9天,收集細(xì)胞,獲得負(fù)載腫瘤抗原的DC疫苗,調(diào)細(xì)胞數(shù)為1×106/mL。
1.2.2 S180荷瘤小鼠模型的建立及動(dòng)物分組 將小鼠肛門肉瘤S180細(xì)胞接種于小鼠腹腔,待腹部膨出時(shí),抽取腹水,以生理鹽水稀釋,進(jìn)行細(xì)胞計(jì)數(shù),調(diào)整細(xì)胞濃度為1×107/mL,于小鼠右腋筋膜下接種0.2 mL,每次接種40只。將荷瘤第5天的小鼠隨機(jī)分為模型組、環(huán)磷酰胺組、黃芪多糖組、細(xì)胞因子組,每組10只。
1.2.3 荷瘤小鼠免疫治療 模型組腹腔注射生理鹽水0.2 mL,其余3組分別經(jīng)荷瘤部位和腹腔注射,環(huán)磷酰胺組注射環(huán)磷酰胺50 mg/kg,黃芪多糖組注射經(jīng)黃芪多糖誘導(dǎo)的DC疫苗0.2 mL,細(xì)胞因子組注射經(jīng)TNF-α誘導(dǎo)的DC疫苗0.2 mL。5 d后再注射1次。
1.2.4 檢測(cè)指標(biāo) (1)胸腺指數(shù)、脾臟指數(shù)、抑瘤率。荷瘤第12天,頸椎脫位法處死小鼠。剝離小鼠胸腺、脾臟及腫瘤組織,用濾紙吸干并稱質(zhì)量,分別計(jì)算胸腺指數(shù)、脾臟指數(shù)及抑瘤率。胸腺指數(shù)=胸腺質(zhì)量(mg)/體質(zhì)量(g),脾臟指數(shù)=脾臟質(zhì)量(mg)/體質(zhì)量(g),抑瘤率(%)=(模型組平均瘤質(zhì)量-實(shí)驗(yàn)組平均瘤質(zhì)量)/模型組平均瘤質(zhì)量×100%。(2)IL-4、IFN-γ的檢測(cè)。荷瘤第12天,各組小鼠經(jīng)眼球摘除法采血,4℃靜置過(guò)夜,次日3 000 r/min離心10 min,收集血清,用ELISA法檢測(cè)小鼠血清IL-4、IFN-γ水平,嚴(yán)格按照ELISA試劑盒操作說(shuō)明進(jìn)行。
2.1 DC的形態(tài)與表型鑒定 單個(gè)核細(xì)胞形態(tài)規(guī)則呈球形,透光度好,細(xì)胞膜表面光滑。加入細(xì)胞因子后第3天,細(xì)胞呈半貼壁,部分細(xì)胞懸浮,體積增大,形狀不規(guī)則似星形、梭形,有少量突起。第5天,細(xì)胞變圓,有大量突起,可見(jiàn)不太規(guī)則的樹(shù)突狀外形。第7天,懸浮細(xì)胞增多,胞漿透明,胞體增大,有毛刺樣突起,呈典型的DC形態(tài)。見(jiàn)圖1。DC培養(yǎng)第7天,黃芪多糖組細(xì)胞表面CD80陽(yáng)性、CD86陽(yáng)性及CD80和CD86雙陽(yáng)性的表達(dá)率顯著高于細(xì)胞因子組(P<0.05),見(jiàn)表1。
Fig.1 The morphology of DC induced by cytokines and astragalus polysaccharide(×200)圖1 細(xì)胞因子和黃芪多糖誘導(dǎo)的DC形態(tài)(×200)
Tab.1 Expressions of CD80 and CD86 on DC induced by cytokines and astragalus polysaccharide表1 細(xì)胞因子和黃芪多糖誘導(dǎo)的DC表面CD80、CD86表達(dá)情況 (n=10,%,±s)
Tab.1 Expressions of CD80 and CD86 on DC induced by cytokines and astragalus polysaccharide表1 細(xì)胞因子和黃芪多糖誘導(dǎo)的DC表面CD80、CD86表達(dá)情況 (n=10,%,±s)
*P<0.05
?
2.2 黃芪多糖誘導(dǎo)的DC疫苗對(duì)S180荷瘤小鼠的抑瘤作用 環(huán)磷酰胺組、細(xì)胞因子組、黃芪多糖組的瘤體質(zhì)量低于模型組,抑瘤率分別為35.11%、64.10%、64.25%,黃芪多糖組瘤體質(zhì)量低于環(huán)磷酰胺組(P<0.05),而與細(xì)胞因子組無(wú)明顯差異(P>0.05),見(jiàn)表2。
2.3 黃芪多糖誘導(dǎo)的DC疫苗對(duì)S180荷瘤小鼠免疫器官指數(shù)的影響 與環(huán)磷酰胺組相比,黃芪多糖組、細(xì)胞因子組小鼠的胸腺指數(shù)、脾臟指數(shù)均顯著提高(P<0.05),而黃芪多糖組與細(xì)胞因子組之間無(wú)明顯差異(P>0.05),見(jiàn)表2。
Tab.2 Comparison of tumor weight and immune organ index between four groups of mice表2 各組荷瘤小鼠的瘤體質(zhì)量與免疫器官指數(shù)(n=10,±s)
Tab.2 Comparison of tumor weight and immune organ index between four groups of mice表2 各組荷瘤小鼠的瘤體質(zhì)量與免疫器官指數(shù)(n=10,±s)
*P<0.05,**P<0.01;a與模型組比較,b與環(huán)磷酰胺組比較,P<0.05
組別模型組環(huán)磷酰胺組細(xì)胞因子組黃芪多糖組F或χ2瘤體質(zhì)量(g)2.011±0.032 1.305±0.018a0.722±0.015ab0.719±0.023ab33.052**胸腺指數(shù)(mg/g)2.11±0.15 1.45±0.22a1.74±0.38ab1.69±0.26ab7.831*脾臟指數(shù)(mg/g)4.77±0.36 3.54±0.52a5.31±0.81ab5.44±0.76ab11.324*
2.4 黃芪多糖誘導(dǎo)的DC疫苗對(duì)S180荷瘤小鼠血清IL-4、IFN-γ水平的影響 與模型組比較,黃芪多糖組、細(xì)胞因子組小鼠血清IL-4水平顯著下降,IFN-γ水平明顯增加(P<0.05)。黃芪多糖組與細(xì)胞因子組相比,IL-4、IFN-γ水平差異無(wú)統(tǒng)計(jì)學(xué)意義,見(jiàn)表3。
Tab.3 Comparison of serum levels of IL-4 and IFN-γ between four groups of mice表3 各組小鼠血清IL-4、IFN-γ水平比較(n=10,ng/L,±s)
Tab.3 Comparison of serum levels of IL-4 and IFN-γ between four groups of mice表3 各組小鼠血清IL-4、IFN-γ水平比較(n=10,ng/L,±s)
**P<0.01;a與模型組比較,b與環(huán)磷酰胺組比較,P<0.05
組別模型組環(huán)磷酰胺組細(xì)胞因子組黃芪多糖組F IL-4 19.08±3.11 23.95±6.07a14.72±4.84a15.66±2.57a10.253**IFN-γ 11.23±0.77 10.37±2.19 17.20±2.03ab16.54±3.71ab17.560**
黃芪多糖對(duì)肝癌、乳腺癌、胃癌等腫瘤細(xì)胞具有明顯的抑制作用,可以增強(qiáng)實(shí)驗(yàn)動(dòng)物的免疫功能,發(fā)揮抗腫瘤的作用。很多研究結(jié)果提示黃芪多糖可通過(guò)抑制腫瘤細(xì)胞生長(zhǎng)[3]、促進(jìn)抗腫瘤細(xì)胞因子分泌[4]、誘導(dǎo)細(xì)胞周期停滯[5]、降低端粒酶活性[6]等機(jī)制發(fā)揮抗腫瘤作用。鄧旻等[7]研究發(fā)現(xiàn)黃芪多糖體可在體外誘導(dǎo)臍血單核細(xì)胞定向分化為成熟的DC,但關(guān)于黃芪多糖誘導(dǎo)的DC體內(nèi)抗腫瘤作用的研究較少。
本研究發(fā)現(xiàn)黃芪多糖誘導(dǎo)小鼠骨髓來(lái)源的未成熟DC呈典型的DC形態(tài),其表面協(xié)同刺激分子CD80、CD86的表達(dá)顯著高于細(xì)胞因子誘導(dǎo)的成熟DC,提示黃芪多糖可以有效誘導(dǎo)DC表達(dá)協(xié)同刺激分子,利于DC提呈抗原。用S180腫瘤全抗原致敏的DC腫瘤疫苗對(duì)S180荷瘤小鼠進(jìn)行免疫治療,結(jié)果顯示黃芪多糖組、細(xì)胞因子組小鼠的瘤體質(zhì)量低于模型組和環(huán)磷酰胺組,而胸腺指數(shù)、脾臟指數(shù)顯著高于陽(yáng)性對(duì)照環(huán)磷酰胺組,與細(xì)胞因子組相比,黃芪多糖組的各項(xiàng)指標(biāo)均無(wú)明顯差異,提示黃芪多糖誘導(dǎo)的DC腫瘤疫苗在抗腫瘤的同時(shí),能改善荷瘤小鼠的免疫功能。
Th1介導(dǎo)的細(xì)胞免疫在機(jī)體抗腫瘤免疫中占有重要地位。正常情況下,Th1和Th2處于相對(duì)穩(wěn)定狀態(tài),并相互制約,以維持機(jī)體正常的免疫功能[8]。很多腫瘤患者體內(nèi)發(fā)生Th1細(xì)胞受到抑制而Th2細(xì)胞占優(yōu)勢(shì)的現(xiàn)象,即Th1/Th2漂移,機(jī)體的抗腫瘤免疫受到嚴(yán)重抑制[9]。目前尚無(wú)區(qū)分Th1和Th2細(xì)胞的表面標(biāo)志物,通常以IFN-γ評(píng)判Th1細(xì)胞功能,IL-4評(píng)判Th2細(xì)胞功能。本研究顯示,黃芪多糖組、細(xì)胞因子組小鼠血清IFN-γ水平顯著升高,IL-4水平顯著下降,提示黃芪多糖誘導(dǎo)的DC疫苗能糾正荷瘤小鼠的Th1/Th2失衡,改善免疫狀態(tài),增強(qiáng)抗腫瘤的免疫功能。
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(2014-05-10收稿 2014-06-30修回)
(本文編輯 閆娟)
The Inhibitory Effect of Dendritic Cell Tumor Vaccine Induced by Astragalus Polysaccharides on the Expression of Cytokines Th1/Th2 in S180 Tumor-Bearing Mice
JING Xuening1,QIU Bo2,ZHAN Wenxiang1,WU Jibiao1
1 Shandong College of Traditional Chinese Medicine,Yantai 264199,China;2 Yantai Central Hospital of Laiyang City
ObjectiveTo study the antitumor effects of dendritic cell vaccine induced by astragalus polysaccharides on S180 tumor-bearing mice,and its possible mechanism.MethodsDendritic cells derived from mouse bone marrow were induced maturation by astragalus polysaccharides and loaded with S180 tumor antigen to prepare tumor vaccine.Tumor-bearing mice were divided into four groups and treated on day-5 and day-10 respectively.Group A was injected with NS,Group B with CTX(50 mg/kg),Group C with dendritic cells induced by astragalus polysaccharides and Group D with dendritic cells induced by tumor necrosis factor(TNF)-α.After 12 days of tumor-bearing,the animals were killed.The subcutaneous sarcoma,thymus and spleen were separated and weighted.The inhibitory rate,thymus index and spleen index were then calculated.ELISA assay was used to detect the levels of interleukin(IL)-4,interferon(IFN)-γ in serum of tumor bearing mice.ResultsThe tumor inhibition rate was higher in astragalus polysaccharide group and cytokine group than that of CTX group(64.25%,64.10%vs 35.11%).The thymus index was higher in astragalus polysaccharide group and cytokine group than that of CTX group(1.69±0.26,1.74±0.38 vs 1.45±0.22).The spleen index was higher in astragalus polysaccharide group and cytokine group than that of CTX group(5.44±0.76,5.31±0.81 vs 3.54±0.52).The level of IL-4 was lower in astragalus polysaccharide group and cytokine group than that of CTX group(15.66±2.57,14.72±4.84 vs 23.95± 6.07).The level of IFN-γ was higher in astragalus polysaccharide group and cytokine group than that of CTX group(16.54± 3.71,17.20±2.03 vs 10.37±2.19).All the differences were statistically significant(P<0.05).ConclusionDendritic cell vaccine induced by astragalus polysaccharides can effectively inhibit tumor growth.Its mechanism may be associated with the promotion spleen index and thymus index of S180 tumor-bearing mice,the effective correction of Th1/Th2 imbalance induced by tumor,and the enhancement of antitumor immune responses.
astragalan;dendritic cells;interleukin-4;interferon typeⅡ;tumor inhibition rate;thymus index;spleen index;Th1/Th2
R730.3
A
10.3969/j.issn.0253-9896.2014.11.007
山東省中醫(yī)藥科學(xué)技術(shù)研究項(xiàng)目(2009-254)
1山東煙臺(tái),山東中醫(yī)藥高等??茖W(xué)校(郵編264199);2煙臺(tái)市萊陽(yáng)中心醫(yī)院