Host-inducible immunogenic sphingomyelinase-like protein, Lk73.5, of Leptospira interrogans
Host-inducible immunogenic sphingomyelinase-like protein, Lk73.5, of Leptospira interrogans
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DOI：
10.1128/iai.72.2.742-749.2004
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发表时间：
2004-02-01
影响因子：
3.1
通讯作者：
Verma, A
中科院分区：
文献类型：
--
作者：
Artiushin, S;Timoney, JF;Verma, A
问号钩端螺旋体在动物和人类中引起多种临床综合征。虽然已经积累了很多关于钩端螺旋体脂多糖在保护性抗体反应中的重要性的信息，但对参与免疫反应的蛋白质知之甚少。鉴定仅在宿主中诱导的那些蛋白质是特别困难的。利用一种新的双抗体筛选法，从L.在表达宿主诱导蛋白质的问号波摩那血清型中，我们已经表征了编码648个氨基酸的鞘磷脂酶样前蛋白的基因（lk75.3），所述鞘磷脂酶样前蛋白具有对马肺内皮细胞的细胞毒性活性和对马和兔红细胞的弱溶血活性。lk73.5在所有血清型中均为单基因拷贝。问号钩端螺旋体，而不是其他钩端螺旋体属。除了L.稻台。Lk73.5的开放阅读框（ORE）之后是另一个部分同源的序列，该序列含有28.7-kDa肽的ORF（类E2）。Lk73.5和Sph-like 2与L.赖型问号线虫（S. X. Ren，G.福，X。- G.江克河Zeng，Y.- G.苗，H. Xu，Y-X. Zhang，H. Xiong，G.卢湖F.卢，H.- Q. Jiang，J. Jia，Y.- F. Tu，J.- X.江伟Y.顾，Y.- Q. Zhang，Z.蔡，H。- H. Sheng，H.- F. Yin，Y.张，G.- F. Zhu，M. Wank，H. L. Huangic，Z. Qian，S.- Y. Wang，Wei Ma，Z. J. Yao，Y.沈，B.- Q. Qiang，Q.- C.夏，X。- K. Guo，中国古猿A.丹钦湖S.吉龙河L.萨默维尔，Y.- M.温，M.- H. Shik，Z.陈杰G.徐克和G.- P. Zhao，Nature 422：88- 893，2003）。也存在与来自其它钩端螺旋体和其它细菌的鞘磷脂酶的实质性同源性。在30 ℃和37 ℃培养的钩端螺旋体中未检测到Lk73.5。重组蛋白与最近感染的马血清反应强烈，但与用商业五价马毒素接种的马血清反应不强烈。宿主诱导的免疫原性Lk73.5在区分疫苗和感染免疫应答中具有重要价值。
Leptospira interrogans causes a variety of clinical syndromes in animals and humans. Although much information has accumulated on the importance of leptospiral lipopolysaccharide in protective antibody responses, relatively little is known about proteins that participate in immune responses. Identification of those proteins induced only in the host is particularly difficult. Using a novel double-antibody screen designed to identify clones in a gene library of L. interrogans serovar Pomona expressing host-inducible proteins, we have characterized a gene (lk75.3) encoding a sphingomyelinase-like preprotein of 648 amino acids with cytotoxic activity for equine pulmonary endothelial cells and weak hemolytic activity for equine and rabbit erythrocytes. lk73.5 was found as a single gene copy in all serovars of L. interrogans but not in other Leptospira spp. except L. inadai. The open reading frame (ORE) for Lk73.5 is followed by another partially homologous sequence containing an ORF (sph-like 2) for a 28.7-kDa peptide. Lk73.5 and Sph-like 2 share 95.1 and 97.7% amino acid identity with putative sphingomyelinases Sph2 and Sph1 (N terminus) from L. interrogans serovar Lai (S.-X. Ren, G. Fu, X.-G. Jiangk, R. Zeng, Y.-G. Miao, H. Xu, Y-X. Zhang, H. Xiong, G. Lu, L.-F. Lu, H.-Q. Jiang, J. Jia, Y.-F. Tu, J.-X. Jiang, W.-Y. Gu, Y.-Q. Zhang, Z. Cai, H.-H. Sheng, H.-F. Yin, Y. Zhang, G.-F. Zhu, M. Wank, H.-L. Huangic, Z. Qian, S.-Y. Wang, Wei Ma, Z.-J. Yao, Y. Shen, B.-Q. Qiang, Q.-C. Xia, X.-K. Guo, A. Danchinq, l. S. Girons, R. L. Somerville, Y.-M. Wen, M.-H. Shik, Z. Chen, J.-G. Xuk, and G.-P. Zhao, Nature 422:88-893,2003). Substantial homologies to sphingomyelinases from other leptospiras and other bacteria are also present. Lk73.5 was not detected in leptospiras cultured at 30 or 37degreesC. The recombinant protein reacted strongly with sera from recently infected mares but not with sera from horses vaccinated with commercial pentavalent bacterin. The host-inducible immunogenic Lk73.5 should ha,,e value in distinguishing vaccine from infection immune response.