本文選題：脂多糖 + 噬菌體隨機(jī)肽庫��； 參考：《第一軍醫(yī)大學(xué)》2005年博士論文

【摘要】：脂多糖(lipopolysacchride,LPS)是引起多種感染性疾病的革蘭氏陰性(G~-)菌重要的共同致病物質(zhì),可導(dǎo)致敗血性休克等嚴(yán)重病理變化。鑒于G~-菌內(nèi)毒素血癥的高發(fā)病率和嚴(yán)重危害,針對LPS的治療與預(yù)防的研究始終是人們極為關(guān)注的課題。目前尚無LPS或類脂A拮抗劑用于臨床或進(jìn)入臨床觀察;而在預(yù)防方面,預(yù)存抗LPS抗體與敗血癥的發(fā)生、大樣本住院腫瘤患者、燒傷、外科手術(shù)等因感染死亡例數(shù)呈負(fù)相關(guān)的現(xiàn)象早已被證實(shí),即對LPS誘發(fā)的病理進(jìn)程有明確的保護(hù)作用,但這種保護(hù)力只限于對接種菌或特定血清型的LPS;而被動(dòng)輸入抗體則有時(shí)相限制,即感染前1小時(shí)內(nèi)應(yīng)用有效,這顯然只適于動(dòng)物實(shí)驗(yàn)。 理想的LPS疫苗應(yīng)能誘導(dǎo)再次免疫應(yīng)答,所產(chǎn)生的抗體應(yīng)是具廣譜預(yù)防與保護(hù)作用。目前LPS疫苗研制所面臨的主要困難包括:①LPS為TI-I(非胸腺依賴抗原-I)型抗原,自然誘導(dǎo)產(chǎn)生的抗體親和力低、調(diào)理殺菌力弱,且無再次抗體應(yīng)答,亦不能誘導(dǎo)特異性細(xì)胞免疫;②源于不同種屬、不同株乃至不同血清型的LPS可具不同的抗原性,只能誘導(dǎo)產(chǎn)生與接種菌或LPS結(jié)合的抗體。因而至今尚無批準(zhǔn)進(jìn)入臨床實(shí)驗(yàn)的具廣譜保護(hù)作用的LPS疫苗。 針對上述存在的問題,本課題的主要研究思路是:利用噬菌體肽庫篩選獲得的短肽模擬LPS的保守性結(jié)構(gòu)表位,將其抗原表位的化學(xué)性質(zhì)由脂多糖改變?yōu)槎屉?由此使TI抗原改變?yōu)門D抗原,進(jìn)而誘導(dǎo)機(jī)體內(nèi)產(chǎn)生有效的再次抗體應(yīng)答和交叉保護(hù)性免疫。 本課題組在前期的工作中,從噬菌體肽庫中篩選了數(shù)十個(gè)模擬位克隆,選擇三個(gè)模擬鼠傷寒桿菌LPS表位的序列合成短肽,并證明用這三種模擬短肽免疫動(dòng)物后,可誘發(fā)機(jī)體產(chǎn)生針對鼠傷寒桿菌LPS的抗體應(yīng)答,但由于所獲模擬位合成肽的免疫原性較弱,加之當(dāng)時(shí)以BSA為載體,所產(chǎn)生的抗體效價(jià)較低,保護(hù)作用亦不明顯。據(jù)此,本研究著重解決了具交叉保護(hù)性抗體的純化,并以
[Abstract]:Lipopolysaccharide (LPSs) is an important common pathogenic substance of Gram-negative GPS-negative bacteria which causes many infectious diseases. It can cause severe pathological changes such as septic shock and so on. In view of the high incidence and serious harm of endotoxemia, the treatment and prevention of LPS has always been a subject of great concern. At present, no LPS or lipoid A antagonist has been used in clinic or in clinical observation. In prevention, there are pre-existing anti LPS antibodies and the occurrence of septicemia, large sample of cancer patients in hospital, burn, The negative correlation in the number of deaths due to infection, such as surgery, has long been confirmed, that is, it has a clear protective effect on the pathological process induced by LPS. However, the protective power is limited to inoculated bacteria or specific serotype LPSs, while passive injection of antibodies is sometimes limited, that is, it is effective within one hour before infection, which is obviously only suitable for animal experiments. The ideal LPS vaccine should be able to induce reimmune response and the antibody produced should have broad-spectrum preventive and protective effects. At present, the main difficulties in the development of LPS vaccine include TI-I (non-thymus dependent antigen-I-1) antigen, low affinity of naturally induced antibodies, weak bactericidal ability, no reantibody response and no specific cellular immunity. (2) LPS derived from different genera, strains or even serotypes had different antigenicity, and could only induce the production of antibodies bound to inoculation bacteria or LPS. So far, no broad spectrum protective LPS vaccine has been approved for clinical trials. In view of the above problems, the main ideas of this study are as follows: the short peptides obtained by phage peptide library are used to mimic the conserved structural epitopes of LPS, and the chemical properties of the epitopes are changed from lipopolysaccharide to short peptides. As a result, TI antigen was transformed into TD antigen, which induced effective reantibody response and cross-protective immunity. In our earlier work, we screened dozens of mimic clones from phage peptide library, selected three mimic LPS epitopes of S. typhimurium to synthesize short peptides, and proved that these three mimic peptides were used to immunize animals. It could induce antibody response against LPS of S. typhimurium, but the immunogenicity of the synthetic peptide was weak, and the antibody titer was low and the protective effect was not obvious. Therefore, this study focused on the purification of the cross-protective antibody, and the purification of the antibody with cross-protective antibody.
【學(xué)位授予單位】：第一軍醫(yī)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2005
【分類號】：R392

【參考文獻(xiàn)】

相關(guān)期刊論文 前3條

1 文維延,韓強(qiáng)濤,富寧;脂多糖保守表位模擬肽的篩選與鑒定[J];生物化學(xué)與生物物理進(jìn)展;2001年02期

2 宗光全,張茂紅,章冠東,杜慶安;嚴(yán)重?zé)齻颊咴缙诙坛虘?yīng)用高效抗生素的研究[J];中華燒傷雜志;2001年02期

3 鄭山根,劉北一,朱平,富寧;交叉保護(hù)性抗LPS多克隆抗體的制備與LPS多表位模擬肽的篩選[J];中華微生物學(xué)和免疫學(xué)雜志;2003年11期

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本文編號：1899451