Identification, characterization, and expression of three new members of the Borrelia burgdorferi Mlp (2.9) lipoprotein gene family.
Identification, characterization, and expression of three new members of the Borrelia burgdorferi Mlp (2.9) lipoprotein gene family.
复制标题
伯氏疏螺旋体 Mlp (2.9) 脂蛋白基因家族三个新成员的鉴定、表征和表达。
DOI：
10.1128/iai.67.11.6008-6018.1999
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发表时间：
1999
影响因子：
3.1
通讯作者：
Norgard,MV
中科院分区：
文献类型：
--
作者：
Yang,X;Popova,TG;Hagman,KE;Wikel,SK;Schoeler,GB;Caimano,MJ;Radolf,JD;Norgard,MV
我们以前报告存在一个家庭的脂蛋白基因，指定2.9脂蛋白基因，编码在至少七个版本的环状（超螺旋）cp 32和cp 18质粒的伯氏疏螺旋体297。2.9脂蛋白的一个显著特征是高度相似的信号序列，但可变的成熟多肽分离成两个抗原类。进一步筛选B. Burgdorferi 297基因组文库导致鉴定出另外三个2.9个脂蛋白基因，重命名为pMLP，用于多拷贝脂蛋白基因。计算机分析和免疫印迹显示Mlp-9与抗原性I类脂蛋白分离，而Mlp-8和Mlp-10是II类脂蛋白的成员。北方杂交结果表明，B.在34°C体外培养中，尽管mlp-9和mlp-10转录本的表达水平很低，但它们的表达量仍然很低。在23、34或37°C下体外培养的疏螺旋体上进行的另外的联合免疫印迹和比较逆转录PCR分析表明，尽管Mlp-8比Mlp-9或Mlp-10显著更丰富，但所有三种lp基因在B.在37°C下进行burgdorferisreplication。当螺旋体在腹膜内植入大鼠的透析膜室（DMC）内生长时，相同的三种脂蛋白的表达进一步增强（即，螺旋体在哺乳动物宿主适应状态），表明温度本身并不能解释themlpgenes的最大上调。某些mlp基因可能在B.用携带B的肩胛硬蜱攻击后，小鼠中针对所有三种Mlp脂蛋白的抗体的发现支持了哺乳动物组织中的伯氏螺旋体。burgdorferi297.组合的数据表明，与以任何相反的方式差异表达相反（例如，OspA/OspC），至少三种基因同时被温度（37°C）和一些其它哺乳动物宿主因子上调。这一发现不仅对理解B.本发明还用于评估一种或多种Mlp脂蛋白是否代表莱姆病的新候选疫苗原。
We previously reported on the existence of a family of lipoprotein genes, designated 2.9 lipoprotein genes, encoded in at least seven versions on the circular (supercoiled) cp32 and cp18 plasmids ofBorrelia burgdorferi297. A distinguishing feature of the 2.9 lipoproteins were highly similar signal sequences but variable mature polypeptides that segregated into two antigenic classes. Further screenings ofB. burgdorferi297 genomic libraries led to the identification of three additional 2.9 lipoprotein genes, renamed hereinmlp, for multicopy lipoprotein genes. Computer analyses and immunoblotting revealed that Mlp-9 segregated with the antigenic class I lipoproteins, whereas Mlp-8 and Mlp-10 were members of class II. Northern blotting showed that all three of themlpgenes were expressed whenB. burgdorferiwas cultivated in vitro at 34°C, althoughmlp-9andmlp-10transcripts were expressed at very low levels. Additional combined immunoblotting and comparative reverse transcription-PCR analyses performed on borreliae cultivated in vitro at 23, 34, or 37°C indicated that although Mlp-8 was substantially more abundant than Mlp-9 or Mlp-10, all three of themlpgenes were upregulated duringB. burgdorferireplication at 37°C. Expression of the same three lipoproteins was further enhanced upon growth of the spirochetes within dialysis membrane chambers (DMCs) implanted intraperitoneally in rats (i.e., spirochetes in a mammalian host-adapted state), suggesting that temperature alone did not account for maximal upregulation of themlpgenes. That certainmlpgenes are likely expressed during the growth ofB. burgdorferiin mammalian tissues was supported by findings of antibodies against all three Mlp lipoproteins in mice after challenge withIxodes scapularisnymphs harboringB. burgdorferi297. The combined data suggest that as opposed to being differentially expressed in any reciprocal fashion (e.g., OspA/OspC), at least threemlpgenes are simultaneously upregulated by temperature (37°C) and some other mammalian host factor(s). The findings have importance not only for understanding alternative modes of differential antigen expression byB. burgdorferibut also for assessing whether one or more of the Mlp lipoproteins represent new candidate vaccinogens for Lyme disease.