Virulence and antigenicity of the szp-gene deleted Streptococcus equi ssp zooepidemicus mutant in mice
Virulence and antigenicity of the szp-gene deleted Streptococcus equi ssp zooepidemicus mutant in mice
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DOI：
10.1016/j.vaccine.2008.10.037
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发表时间：
2009-01-01
期刊：
影响因子：
5.5
通讯作者：
Lu Cheng-ping
中科院分区：
文献类型：
--
作者：
Fan Hong-jie;Tang Fu-yu;Lu Cheng-ping
马链球菌亚种动物寄生虫（Zoopellicus，SEZ）是一种严重的猪传染病。类M蛋白（SzP）是SEZ的一种具有调理素功能的毒力因子。为了制备更好的SEZ疫苗，我们利用同源重组技术构建了szp基因敲除株。通过基因组步移法获得szp基因上游和下游两个片段。然后用该载体从SEZ菌株（ATCC 35246）中删除szp基因的1090 bp片段。与野生型相比，突变株的LD 50降低了1000倍，并且当作为活疫苗施用时，提供了85%的针对强毒株攻击的保护。半定量RT-PCR分析显示免疫小鼠IL-4和IFN-γ mRNA水平显著升高。这些数据表明，szp基因敲除株是一个更好的候选疫苗开发。(c)2008爱思唯尔有限公司保留所有权利。
Streptococcus equi ssp. zooepidemicus (SEZ) causes serious disease in pigs. M-like protein (SzP) of SEZ is a virulence factor with opsonin function. To fabricate better vaccine against SEZ, We have generated a szp-knockout strain by homologous recombination. Two fragments, upstream and downstream of the szp gene, were obtained by genome walking. The vector was then used to delete a 1090 bp segment of szp gene from a strain of SEZ (ATCC35246). The mutant strain had 1000-fold decrease in LD50 as compared with wild type, and provided 85% protection against challenge with a virulent strain when administered as a live vaccine. Semi-quantitative RT-PCR analysis showed a marked increased in levels of IL-4 and IFN-gamma mRNA in immunized mice. These data demonstrate that szp-knockout strain is a better candidate for vaccine development. (c) 2008 Elsevier Ltd. All rights reserved.