趙曉飛,郭景霞,劉曉娟,馬正海
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攜帶HIV-1抗原的單純皰疹病毒載體疫苗的構(gòu)建及鑒定
趙曉飛,郭景霞,劉曉娟,馬正海
新疆大學(xué)生命科學(xué)與技術(shù)學(xué)院,新疆烏魯木齊 830046
趙曉飛, 郭景霞, 劉曉娟, 等. 攜帶HIV-1抗原的單純皰疹病毒載體疫苗的構(gòu)建及鑒定. 生物工程學(xué)報(bào), 2015, 31(3): 384–393.Zhao XF, Guo JX, Liu XJ, et al. Construction and identification of HSV-1 vector vaccine carrying HIV-1 antigen. Chin J Biotech, 2015, 31(3): 384–393.
利用細(xì)菌人工染色體技術(shù)將串聯(lián)的HIV-1160、和基因以及表達(dá)元件插入1型單純皰疹病毒 (Herpes simplex virus type 1, HSV-1) 內(nèi)部反向重復(fù)序列區(qū),以獲得攜帶HIV-1抗原的單純皰疹病毒載體疫苗。首先將HIV-1160 (B型和C型)、和基因串聯(lián)克隆入pcDNA3獲得重組質(zhì)粒pcDNAB和pcDNA/C,重組質(zhì)粒轉(zhuǎn)染293FT細(xì)胞,Western blotting檢測(cè)HIV抗原表達(dá)。繼而將pcDNAB和pcDNA/C中包括HIV-1抗原基因和表達(dá)元件的表達(dá)框克隆入pKO5/BN獲得重組穿梭質(zhì)粒pKO5/BN/B和pKO5/BN/C,穿梭質(zhì)粒電轉(zhuǎn)含BAC-HSV的大腸桿菌,篩選重組菌,提取重組DNA并轉(zhuǎn)染Vero細(xì)胞,挑取病毒蝕斑純化重組病毒,Southern blotting鑒定重組病毒DNA,Western blotting檢測(cè)重組病毒感染細(xì)胞中HIV抗原表達(dá),并分析病毒的增殖特性。結(jié)果表明,Western blotting在pcDNA/B和pcDNA/C轉(zhuǎn)染的293FT細(xì)胞中檢測(cè)到表達(dá)的gp160和gag蛋白。pKO5/BN/B和pKO5/BN/C分別電轉(zhuǎn)獲得重組菌,并從重組DNA轉(zhuǎn)染的Vero細(xì)胞中純化獲得重組HSV,Southern blotting 檢測(cè)表明重組HSV基因組發(fā)生特異性重組,重組病毒感染細(xì)胞中檢測(cè)到gp120和gp41,且重組HSV保留了在哺乳動(dòng)物細(xì)胞中的復(fù)制能力。本研究獲得攜載HIV-1160、和基因的重組HSV,并保留了在哺乳動(dòng)物細(xì)胞中的復(fù)制能力,可作為HIV-1復(fù)制型病毒載體疫苗。
1型單純皰疹病毒,HIV-1抗原,病毒載體疫苗,細(xì)菌人工染色體
人類免疫缺陷病毒 (Human immune deficiency virus, HIV) 感染機(jī)體后主要侵犯 CD4+ T 細(xì)胞,導(dǎo)致機(jī)體免疫缺陷并繼發(fā)各種機(jī)會(huì)性感染和腫瘤。自首例艾滋病報(bào)道以來,全球科學(xué)家一直致力于艾滋病疫苗的研制[1]。針對(duì)HIV這類高度變異、攻擊免疫系統(tǒng)且能引起持續(xù)感染和產(chǎn)生免疫病理反應(yīng)的病毒而言,研制能有效誘導(dǎo)機(jī)體全面免疫反應(yīng)的疫苗尤為重要。目前,HIV病毒樣顆粒疫苗、亞單位疫苗、合成多肽疫苗、DNA疫苗、細(xì)菌活載體疫苗和病毒載體疫苗均見報(bào)道,上述疫苗在非人類靈長(zhǎng)類動(dòng)物模型中均可引起不同程度的免疫保護(hù)反應(yīng)。
HSV-1是一種嗜神經(jīng)性病毒,在人群中感染非常普遍,常見的臨床表現(xiàn)為黏膜和皮膚局部集聚的皰疹等輕微癥狀[2]。HSV-1為雙鏈DNA病毒,基因組152 kb,由獨(dú)特的長(zhǎng)片段 (Unique long sequence, UL) 和短片段 (Unique short sequence, US) 組成,兩端為末端重復(fù)序列,兩片段連接處為內(nèi)部反向重復(fù)序列 (Internal inverted repead sequence,IR)[2]。HSV-1編碼約90種蛋白,功能大多已明確,其中約一半為病毒復(fù)制所必需,另一些為復(fù)制非必需,刪除非必需基因并以外源基因代之不會(huì)影響病毒復(fù)制,故HSV-1可改造為病毒載體。HSV-1作為疫苗載體有其獨(dú)特的優(yōu)勢(shì),如:HSV-1感染機(jī)體后潛伏于神經(jīng)元,機(jī)體針對(duì)HSV-1的預(yù)存免疫很低; HSV-1載體疫苗可通過口服和黏膜等途徑免疫并激發(fā)機(jī)體全面的免疫應(yīng)答;另外,有研究表明HSV-1能激發(fā)機(jī)體的固有免疫反應(yīng)[3]。與其他病毒載體相比,HSV-1作為HIV載體疫苗的優(yōu)勢(shì)在于其宿主范圍廣、感染效率高、基因組游離存在、抗皰疹病毒藥物可終止治療意外感染和具有靶向性,遺傳背景清楚,重組方法成熟[4-5]等 方面。
目前,以HSV-1為載體的HIV-1疫苗已有報(bào)道[6-8],這些疫苗能夠誘導(dǎo)HIV-1特異性的細(xì)胞免疫和體液免疫反應(yīng)。本研究利用細(xì)菌人工染色體技術(shù)將串聯(lián)的HIV-1160、和抗原基因以及表達(dá)元件重組至IR區(qū),以期獲得新型HIV病毒載體疫苗。
1.1 菌種、質(zhì)粒及細(xì)胞系
含HSV-1 F株全長(zhǎng)基因組的細(xì)菌人工染色體BAC-HSV及其轉(zhuǎn)化的大腸桿菌、含HSV-1基因組HⅠB片段的質(zhì)粒pRB112由芝加哥大學(xué)微生物系Roizman Bernard教授惠贈(zèng)。穿梭質(zhì)粒pKO5/BN為研究組前期構(gòu)建,含HSV-1基因組HⅠB片段和HⅠN片段,在本研究中兩個(gè)片段為同源重組臂。pIRES/和pcDNA3.1質(zhì)粒為本室保存。pcDNA3/160B、pcDNA3/160C、pMT/Bip/v5-his-、HIV-1 Bru3以及183H12細(xì)胞 (gag單克隆抗體雜交瘤細(xì)胞) 均由上海巴斯德研究所周保羅研究員惠贈(zèng)。293FT和Vero細(xì)胞系為本室保存。
1.2 主要試劑
DNA marker 購(gòu)自東盛公司;限制性內(nèi)切酶、T4 DNA連接酶、Ex、AMV反轉(zhuǎn)錄酶、Klenow Fragment、DNA連接試劑盒均購(gòu)自TaKaRa寶生物公司;RNA提取試劑盒、DNA回收及純化試劑盒購(gòu)自天根生化科技 (北京) 有限公司;質(zhì)粒大量提取試劑QIAGEN Plasmid Maxi Kit購(gòu)自QIAGEN公司;細(xì)胞培養(yǎng)液基質(zhì)HGDMEM和Medium 199購(gòu)自GIBCO公司;Southern blotting試劑盒購(gòu)自Roche公司;轉(zhuǎn)染試劑Lipofectamine 2 000購(gòu)自Invitrogen公司;其余試劑均為國(guó)產(chǎn)分析純。
1.3 引物設(shè)計(jì)及合成
根據(jù)GenBank公布的HIV-1基因組序列設(shè)計(jì)引物序列 (表1)。
1.4 方法
1.4.1 HIV-1抗原基因串聯(lián)質(zhì)粒的構(gòu)建及鑒定
質(zhì)粒HIV-1 Bru 3含HIV-1全長(zhǎng)基因組,以其為模板PCR擴(kuò)增片段,以該片段替換pIRES/中的Neo基因,即經(jīng)Ⅰ和Ⅰ位點(diǎn)克隆入pIRES/,獲得重組質(zhì)粒pIRES/;將pMT/Bip/v5-經(jīng)Ⅰ(消化后補(bǔ)平) 和RⅠ酶切獲得的片段經(jīng)HⅠ(消化后補(bǔ)平) 和RⅠ克隆入pIRES/多克隆位點(diǎn),獲得重組質(zhì)粒pIRES//;RⅠ (消化后補(bǔ)平)和Ⅱ酶切pIRES//獲得含HIV-1和的DNA片段,以之取代pcDNA3/160B和pcDNA3/160C中的新霉素抗性基因,即經(jīng)Ⅰ和Ⅱ位點(diǎn)克隆入pcDNA3/160B和pcDNA3/160C,獲得重組質(zhì)粒pcDNA3/160B//(pcDNA/B) 和pcDNA3/160C//(pcDNA/C),酶切鑒定重組質(zhì)粒。
表1 HIV-1基因組所需擴(kuò)增基因的引物序列
pcDNA/B和pcDNA/C分別轉(zhuǎn)染293FT細(xì)胞,于CO2培養(yǎng)箱37 ℃培養(yǎng)48 h后收集細(xì)胞,常規(guī)方法裂解細(xì)胞,Western blotting 檢測(cè)細(xì)胞裂解液上清和沉淀中的HIV抗原。
1.4.2 重組穿梭質(zhì)粒的構(gòu)建和重組BAC-HSV的篩選
pcDNA/B和pcDNA/C分別經(jīng)Ⅰ和Ⅰ (消化后補(bǔ)平) 雙酶切后得到HIV-1抗原基因串聯(lián)的DNA片段,并經(jīng)R Ⅴ位點(diǎn)克隆入穿梭質(zhì)粒pKO5/BN,獲得重組質(zhì)粒pKO5/BN/160B//(pKO5/BN/B)和pKO5/ BN/gp160C//(pKO5/BN/C),酶切鑒定重組質(zhì)粒。
按Horsburgh等[9]報(bào)道的方法制備含BAC-HSV大腸桿菌的感受態(tài)細(xì)胞,以pKO5/BN/B和pKO5/BN/C分別電轉(zhuǎn)感受態(tài)細(xì)胞,轉(zhuǎn)化細(xì)胞經(jīng)溫度 (包括43 ℃和30 ℃) 以及添加抗生素 (包括氯霉素和博萊霉素) 和蔗糖的培養(yǎng)基篩選重組菌,菌落PCR檢測(cè)重組菌中HIV-1抗原基因。按QIAGEN Plasmid Maxi Kit說明書提取重組菌DNA,PCR鑒定重組BAC-HSV。
1.4.3 重組病毒的純化與鑒定
重組BAC-HSV轉(zhuǎn)染Vero細(xì)胞后收集病毒蝕斑區(qū)細(xì)胞,經(jīng)凍融和超聲處理的細(xì)胞裂解液感染Vero細(xì)胞,經(jīng)3輪蝕斑挑選純化病毒,隨后大量感染Vero細(xì)胞并提取重組病毒基因組。以pRB112中HⅠ和Ⅰ酶切片段為模板,隨機(jī)引物法制備探針,病毒基因組經(jīng)RⅠ酶切、電泳并轉(zhuǎn)至硝酸纖維素膜上進(jìn)行Southern blotting檢測(cè),探針制備及Southern blotting按DIG DNA Labelling and detection Kit的說明書進(jìn)行。鑒定正確的重組HSV大量感染Vero細(xì)胞,以25 cm2培養(yǎng)瓶為例,每瓶感染細(xì)胞經(jīng)凍融和超聲處理后加入1 mL病毒儲(chǔ)液,于-86 ℃保存?zhèn)溆谩?/p>
1.4.4 Western blotting檢測(cè)重組病毒感染細(xì)胞中HIV抗原的表達(dá)
HSV/Bp和HSV/Cp分別感染Vero細(xì)胞,收集細(xì)胞沉淀,細(xì)胞裂解液經(jīng)SDS-PAGE分離并電轉(zhuǎn)移至硝酸纖維素膜,30 g/L脫脂奶粉4 ℃過夜封閉,按1∶2 000稀釋小鼠抗HIV gp160抗體 (多抗),室溫孵育1.5 h,加入以1∶5 000稀釋的辣根過氧化物酶標(biāo)記的山羊抗鼠IgG,室溫反應(yīng)1 h,DAB避光顯色,拍照。
1.4.5 重組HSV增殖特性的檢測(cè)
重組HSV病毒儲(chǔ)液以無(wú)血清培養(yǎng)基按10倍梯度稀釋后感染Vero細(xì)胞,于CO2培養(yǎng)箱中37 ℃培養(yǎng)1-2 h,期間間斷振蕩培養(yǎng)瓶5-6次,之后換為199?培養(yǎng)基 (含0.1 ‰人γ球蛋白),于CO2培養(yǎng)箱37 ℃培養(yǎng)48 h。細(xì)胞經(jīng)甲醇固定和吉姆薩染液染色后于顯微鏡下進(jìn)行病毒蝕斑計(jì)數(shù),并計(jì)算病毒儲(chǔ)液的蝕斑形成單位 (Plaque forming unit,PFU)。重組HSV按0.5感染復(fù)數(shù) (Multiplicity of infection, MOI) 感染Vero細(xì)胞,分別于感染后12 h、18 h、24 h、48 h收集感染細(xì)胞,并按上述方法測(cè)定細(xì)胞裂解液中重組病毒的PFU,繪制重組病毒在Vero細(xì)胞中的生長(zhǎng)曲線。
2.1 HIV-1抗原基因串聯(lián)質(zhì)粒的鑒定
pcDNA/B和pcDNA/C中HIV-1抗原基因及表達(dá)元件的結(jié)構(gòu)如圖1A所示。圖1B為pcDNA/B的酶切鑒定結(jié)果,該質(zhì)粒經(jīng)Ⅰ酶切產(chǎn)生3 416 bp和6 456 bp的DNA片段;經(jīng)Ⅰ酶切產(chǎn)生9 872 bp的DNA片段;經(jīng)Ⅰ酶切產(chǎn)生2 479 bp和7 393 bp的DNA片段;經(jīng)Ⅰ和Ⅰ雙酶切產(chǎn)生7 200 bp、2 500 bp和172 bp的DNA片段;經(jīng)Ⅰ和HⅠ雙酶切產(chǎn)生2 600 bp和7 272 bp的DNA片段;經(jīng)Ⅰ和Ⅱ雙酶切產(chǎn)生2 690 bp和7 182 bp的DNA片段;經(jīng)RⅠ和Ⅰ雙酶切產(chǎn)生 3 563 bp和6309 bp的DNA片段;以上結(jié)果均與預(yù)期相符。pcDNA3/C經(jīng)上述酶酶切鑒定亦正確。
pcDNA/B和pcDNA/C轉(zhuǎn)染293FT細(xì)胞后,Western blotting在細(xì)胞沉淀和細(xì)胞裂解液上清中均檢測(cè)到約55 kDa的gag蛋白和約43 kDa的gag蛋白降解產(chǎn)物 (圖2A),以及約160 kDa的gp160蛋白及其降解產(chǎn)物gp120蛋白 (圖2B)。
2.2 穿梭質(zhì)粒的鑒定和重組BAC-HSV的篩選
PKO5/BN/B和pKO5/BN/C的酶切分析見圖3,兩個(gè)重組質(zhì)粒經(jīng)Ⅰ酶切均線性化產(chǎn)生約15 500 bp的DNA片段。pKO5/BN /C經(jīng)RⅠ酶切產(chǎn)生約8 500 bp和7 000 bp的DNA片段,經(jīng)Ⅰ酶切產(chǎn)生約15 000 bp和500 bp的DNA片段,經(jīng)Ⅰ酶切產(chǎn)生約6 900 bp、 6 300 bp和1 800 bp的DNA片段,說明串聯(lián)的HIV-1基因表達(dá)框正向克隆入pKO5/BN質(zhì)粒。pKO5/BN/B經(jīng)R Ⅰ酶切產(chǎn)生約14 700 bp和800 bp的DNA片段,經(jīng)Ⅰ酶切產(chǎn)生約12 900 bp和2 600 bp的DNA片段,經(jīng)Ⅰ酶切產(chǎn)生約6 300 bp、5 800 bp和2 900 bp的DNA片段,說明串聯(lián)的HIV-1基因表達(dá)框反向克隆入pKO5/BN質(zhì)粒。
圖1 pcDNA3/gBgp和pcDNA3/gCgp的結(jié)構(gòu)及其酶切分析
圖2 pcDNA3/gBgp和pcDNA3/gCgp轉(zhuǎn)染細(xì)胞中g(shù)ag和gp160的檢測(cè)
圖3 pKO5/BN/gBgp和pKO5/BN/gCgp的酶切分析
2.3 重組病毒的純化與鑒定
重組BAC-HSV轉(zhuǎn)染Vero細(xì)胞后獲得病毒蝕斑,挑取病毒蝕斑并在Vero細(xì)胞連續(xù)傳代以純化病毒,圖4為在Vero細(xì)胞中獲得的三輪病毒蝕斑。純化的重組HSV大量感染Vero細(xì)胞并提取病毒基因組,Southern blotting檢測(cè)到約 7 000 bp的重組區(qū)特異性DNA片段 (圖5),說明重組病毒正確,分別命名為HSV/B和HSV/C。
2.4 感染細(xì)胞中HIV抗原的檢測(cè)
經(jīng)Western blotting法檢測(cè),在HSV/B和HSV/B感染的Vero細(xì)胞中均檢測(cè)到約120 kDa大小的gp120和約41 kDa的gp41,正常Vero細(xì)胞中未檢測(cè)到上述特異性蛋白 (圖6)。
2.5 重組HSV增殖特性的檢測(cè)
HSV/B和HSV/C感染Vero細(xì)胞48 h后病毒PFU分別達(dá)到1.26×108PFU/mL和1.53×108PFU/mL,略低于野生型HSV-1感染Vero細(xì)胞48 h時(shí)病毒PFU (3.82×108PFU/mL)。以0.5 MOI重組病毒感染Vero細(xì)胞12 h、18 h、 24 h、48 h時(shí)的病毒PFU略低于野生型HSV-1的PFU,但無(wú)顯著差異 (>0.05) (圖7)。
圖4 重組HSV-1的獲得及純化
圖5 Southern blotting鑒定重組病毒基因組
圖6 重組HSV-1感染細(xì)胞中HIV-1抗原的檢測(cè)
圖7 野生型病毒與重組病毒在Vero細(xì)胞中的生長(zhǎng)曲線
近年來,艾滋病疫苗領(lǐng)域出現(xiàn)了許多新的疫苗設(shè)計(jì)理念,如改造HIV天然抗原的新免疫原設(shè)計(jì)路線、以誘導(dǎo)中和抗體產(chǎn)生為目標(biāo)的B細(xì)胞疫苗技術(shù)路線、以提高免疫原性并兼顧細(xì)胞免疫和體液免疫的復(fù)制型病毒載體疫苗路線以及以誘導(dǎo)黏膜免疫為主的活載體疫苗等技術(shù)路線[10-11]。HIV活載體疫苗能引起較強(qiáng)的細(xì)胞免疫反應(yīng),并能模擬HIV抗原的天然構(gòu)象,已成為HIV疫苗研究的熱點(diǎn)領(lǐng)域,其中以痘病毒和腺病毒為載體的HIV疫苗研究得最為深入[12-13]。HSV-1載體作為基因治療載體和疫苗載體的研究已有很長(zhǎng)的歷史。目前,HSV-1為載體的HIV疫苗也有大量研究,如研究報(bào)道表達(dá)HIV-1和的HSV-1擴(kuò)增子(Amplicon) 能誘導(dǎo)機(jī)體產(chǎn)生針對(duì)HIV的免疫應(yīng)答。Knipe課題組[14]構(gòu)建了含SIV的復(fù)制缺陷型和復(fù)制型HSV-1重組病毒,該研究組將包括gp120、gag和ref-tat-nef融合蛋白在內(nèi)的SIV基因重組至復(fù)制缺陷型HSV-1載體d106中,該重組病毒能誘導(dǎo)短尾猴產(chǎn)生針對(duì)SIV的中和抗體和細(xì)胞免疫反應(yīng),攻毒實(shí)驗(yàn)中免疫組的病毒載量減少。為增強(qiáng)疫苗載體抗原表達(dá)水平和誘導(dǎo)的免疫應(yīng)答水平,該研究組恢復(fù)d106中部分立即早期 (IE) 基因以提高病毒載體的復(fù)制能力,獲得的HSV-1重組病毒d106S細(xì)胞毒性較低,并保持了對(duì)抗皰疹病毒藥物的敏感性,故其安全性較高。目前,研究者已將HIV囊膜蛋白gp120基因重組至d106S并獲得表達(dá)[15]。另有研究者構(gòu)建了含或基質(zhì)蛋白基因等HIV基因的復(fù)制缺陷型HSV-1,這些重組疫苗均能誘導(dǎo)HIV特異性的免疫反應(yīng)[16-17]。
本研究將HIV-1、和基因以及表達(dá)元件串聯(lián)后克隆入真核表達(dá)質(zhì)粒pcDNA3.1,在重組質(zhì)粒pcDNA/B和pcDNA/C轉(zhuǎn)染的293FT細(xì)胞沉淀和細(xì)胞裂解液上清中均檢測(cè)到gag蛋白、gp160蛋白及其降解產(chǎn)物,說明HIV-1抗原基因及表達(dá)元件的串聯(lián)框架保證了各基因的表達(dá),且表達(dá)的gag蛋白和gp160蛋白能夠在細(xì)胞內(nèi)進(jìn)行加工。隨后將HIV-1抗原基因及表達(dá)元件的串聯(lián)框架克隆至穿梭質(zhì)粒pKO5/BN,利用細(xì)菌人工染色體技術(shù)獲得重組BAC-HSV,繼而轉(zhuǎn)染Vero細(xì)胞獲得重組病毒,Southern blotting檢測(cè)結(jié)果表明重組區(qū)已發(fā)生特異性重組。重組HSV-1感染的Vero細(xì)胞中檢測(cè)到gp120和gp41,說明表達(dá)的gp160經(jīng)酶解產(chǎn)生了gp120和gp41,與HIV-1感染細(xì)胞時(shí)gp160的加工過程一致。病毒增殖特性的研究表明,獲得的重組病毒HSV/B和HSV/C在Vero細(xì)胞中的增殖水平略低于野生型HSV-1,但與野生型HSV-1的增殖水平無(wú)顯著性差異 (>0.05)。
研究中,重組病毒的獲得是基于穿梭質(zhì)粒pKO5/BN中HSV-1H ⅠB和H ⅠN片段在含BAC-HSV的大腸桿菌中與HSV-1基因組的同源區(qū)發(fā)生重組,故HIV-1抗原基因及表達(dá)元件的串聯(lián)框架重組至HSV-1基因組的同時(shí),刪除了HSV-1HⅠB和HⅠN片段之間約15 kb的內(nèi)部反向重復(fù)序列 (Internal inverted repeat sequences, IR),IR區(qū)包括3個(gè)IE基因、神經(jīng)毒性基因和病毒潛伏相關(guān)轉(zhuǎn)錄本LAT。Roizman課題組[18]早在1988年就報(bào)道了刪除大部分IR區(qū)并插入HSV-2多個(gè)囊膜糖蛋白編碼基因的重組HSV-1 R7020 (又稱NV1020),構(gòu)建R7020的最初目的是研制預(yù)防HSV-1和HSV-2感染的疫苗,研究中發(fā)現(xiàn)其保留了在哺乳動(dòng)物細(xì)胞中的復(fù)制能力,安全性較高,抗腫瘤活性明顯[19],并將其改造為NV1023、NV1042、NV1066等溶瘤病毒[20]。本研究獲得的重組病毒HSV/B和HSV/C在插入HIV-1多價(jià)抗原的同時(shí)刪除了完整的IR區(qū),其感染特性和安全性等方面可能與R7020有相似之處,本研究也證實(shí)獲得的重組HSV保留了感染能力,其安全性尚待進(jìn)一步研究證實(shí)。
HIV-1疫苗抗原選擇方面,病毒囊膜糖蛋白 (Env) 和衣殼蛋白 (gag) 是主要的候選抗原。HIV-1感染過程中,Env是中和抗體的主要靶點(diǎn),同時(shí)也是誘導(dǎo)中和抗體的主要抗原。gp160是HIV-1 Env的前體蛋白,在宿主細(xì)胞蛋白酶的作用下酶解成gp120和gp41,gp120為外膜蛋白,其上分布有大量的糖基化位點(diǎn)[21-22],gp41為跨膜蛋白,在病毒感染過程中介導(dǎo)病毒脂膜與細(xì)胞膜融合[7,23]。Hocknell等[24]以表達(dá)HIV-1 gp120的HSV-1擴(kuò)增子誘導(dǎo)小鼠產(chǎn)生了較強(qiáng)的細(xì)胞免疫和體液免疫反應(yīng)。Gag作為免疫原主要激發(fā)細(xì)胞免疫反應(yīng),能自我裝配成病毒粒顆粒 (VLP)[25-27],經(jīng)改造后仍能夠自我組裝成VLP并保持天然構(gòu)象。Parker等[7]構(gòu)建了表達(dá)gag的復(fù)制型重組HSV-1,其可誘導(dǎo)小鼠產(chǎn)生特異性細(xì)胞免疫反應(yīng)。除Env和gag之外,Pol、Tat、Nef等為抗原以及多價(jià)抗原的HIV疫苗研究也均見報(bào)道。本研究中將HIV-1 B型和C型,和基因的表達(dá)框重組至HSV獲得HIV-1多價(jià)病毒載體疫苗,表達(dá)的gp160和gag經(jīng)宿主細(xì)胞蛋白酶和外源表達(dá)的protease降解及各組分間互作更接近HIV-1感染細(xì)胞時(shí)HIV-1蛋白表達(dá)和加工的過程,其誘發(fā)的免疫反應(yīng)也將針對(duì)并阻斷HIV-1感染過程,我們后期將通過動(dòng)物免疫試驗(yàn)深入探討該載體疫苗的免疫效果。
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(本文責(zé)編 郝麗芳)
Construction and identification of HSV-1 vector vaccine carrying HIV-1 antigen
Xiaofei Zhao, Jingxia Guo, Xiaojuan Liu, and Zhenghai Ma
College of Life Science and Technology Xinjiang University, Urumqi 830046, Xinjiang, China
To construct an HSV-1 vector vaccine carrying HIV-1 antigens, HIV-1160,,and the expression elements were chained together, and then inserted into the internal inverted repeat sequence region of HSV-1 by bacterial artificial chromosome technology. Firstly, HIV-1(including type B and C),andgenes were cloned into pcDNA3 in series to generate the pcDNA/Band pcDNA/C, then the recombinant plasmids were transfected into 293FT cells, and HIV-1 antigen was detected from transfected cells by Western blotting. Then the expression cassettes from pcDNA/Band pcDNA/C, comprising HIV-1 antigen genes and expression elements, were cloned into pKO5/BN to generate the shuttle plasmids pKO5/BN/Band pKO5/BN/C. The shuttle plasmids were electroporated intocells that harbor an HSV-BAC, the recombinant bacteria were screened, and the recombinant DNA was extracted and transfected into Vero cells. The recombinant virus was purified through picking plaques, the virus’ DNAs were identified by Southern blotting; HIV-1 antigen was detected from the recombinant HSV-1 infected cells by Western blotting, and the virus’ replication competent was analyzed. As the results, gp160 and gag proteins were detected from 293FT cells transfected with pcDNA/Band pcDNA/Cby Western blotting. The recombinant bacteria were generated from theelectroporated with pKO5/BN/Bor pKO5/BN/C. The recombinant HSV was purified from the Vero cells transfected with the recombinant DNA, the unique DNA fragment was detected from the genome of recombination HSV by Southern blotting; gp120 and gp41 were detected from the infected cells by Western blotting, and the recombinant HSV retained replication competent in mammalian cells. The results indicate that the recombinant HSV carrying HIV-1,andgenes was generated, the virus retains replication competent in mammalian cells, and could be used as a replicated viral vector vaccine.
herpes simplex virus type 1, HIV-1 antigen, a viral vector vaccine, bacterial artificial chromosome
June 10, 2014; Accepted: July 22, 2014
Zhenghai Ma. Tel: +86-991-8582500; E-mail: mzhxju@126.com
Supported by: Xinjiang Uygur Autonomous Region High-tech Research and Development Project (No. 2010016).
2014-08-20
http://www.cnki.net/kcms/doi/10.13345/j.cjb.1400320.html
新疆維吾爾自治區(qū)高技術(shù)研究發(fā)展項(xiàng)目 (No. 2010016) 資助。