K_99和ST_1双价保护性抗原基因重组菌株的表达及其免疫原性研究  

Immunogenicity of ST_1 Fusion Proteins Expressed by ST_1-K_(99)/LacZ Recombinant Strains

作　　者：冯书章[1] 许崇波[1] 刘子[1] 黄培堂[2] 刘晓明[1] 孟锐奇[1] 姚湘燕[1] 李丰生[2] 王玉炯[3] 

机构地区：[1]解放军农牧大学家畜传染病及预防兽医学国家重点学科 [2]军事医学科学院八所 [3]宁夏农学院

出　　处：《中国畜禽传染病》1996年第3期5-9,共5页

基　　金："八.五"科学基金

摘　　要：大肠杆菌耐热性肠毒素(ST_1)是引起幼畜腹泻的重要毒力因子之一,其结构基因编码19个氨基酸,无免疫原性。作者以pSLM_(004)工程菌株为始发菌株,亚克隆ST_1基因,并将ST_1基因分别重组到能有效表达K_(99)菌毛抗原的pGK_(99)之K_(99)基因(pSK_(219))和pUC_(18)多克隆位点中(pXST系列)。从而成功构建了能表达ST_1-K_(99)两种抗原的工程菌苗候选株pSK_(219)以及能表达ST_1抗原的工程菌株pXST。利用这两种基因重组株的表达产物制备了免疫原。经BALB/c鼠免疫效果研究证实,所构建的pS_(219)菌苗候选株安全无毒,且pSK_(219)中K_(99)基因赋于ST_1基因免疫原性。pSK_(219)免疫接种鼠血清及其初乳均可中和ST_1毒性(1个鼠单位),具有较好的免疫保护作用。pSK_(219)工程菌株作为菌苗候选株,为幼畜大肠杆菌性腹泻多价工程菌苗的研制奠定了基础。Heat stable enterotoxin (ST1) gene of ETEC encodes a small peptide of 18 or 19 anino acids which is non-antigenic. ST1 gene (147bp)obtainecl from pBST2-6 was inserted into K99 gene of pGK 99 and polycloning site of PUC18 respectively Two kinds of recombinant plas-mids were constructed pSK219 earring ST1 K99 fusion gene and pXST earring ST1 LacZ fusion gene BALB/c mice were immunized with crude lysate or cell preparation of pSK219 and pXST respectively Either of ST1-K99 fusion protein of pSK219 or ST1-LacZ fusion protein of pXST elicited neutralizing serum antibodies against native ST1 enterotoxin ST1-K99 fusion protein also induced neutralizing colostrum antibodies against native ST1. The results showed that ST1 becomes immunogenic when coupled to appropriative protein carrier (K99 or LacZ).The purpose of these studies was to construct a ST fusion protein which is suiable for a multiva-lent vaccine against ETEC and the recombinant strain pSK219 can be used as a vaccine candidate against ST enterotoxin and K99 pilus of ETEC.

关 键 词：K99 ST1 抗原 基因重组菌株 免疫原性 

分 类 号：S852.43[农业科学—基础兽医学]