Resistance of Mycoplasma pulmonis to complement lysis is dependent on the number of vsa tandem repeats:: Shield hypothesis
Resistance of Mycoplasma pulmonis to complement lysis is dependent on the number of vsa tandem repeats:: Shield hypothesis
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DOI：
10.1128/iai.72.12.6846-6851.2004
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发表时间：
2004-12-01
影响因子：
3.1
通讯作者：
Dybvig, K
中科院分区：
文献类型：
--
作者：
Simmons, WL;Denison, AA;Dybvig, K
Vsa蛋白与鼠呼吸道病原体肺支原体的毒力相关。抗原由保守的N-末端区域组成，其与由串联重复序列组成的几个不同可变C-末端区域之一组合。M.产生具有约40个串联重复的VsaA的肺杆菌菌株不粘附于聚苯乙烯或红细胞，并且对补体杀伤具有高度抗性。产生具有三个串联重复的VsaA的菌株强烈粘附于聚苯乙烯和红细胞，并且对补体杀伤高度敏感。我们在这里报告说，补体溶解的阻力是不是由于缺乏激活的补体级联。分离并分析了M.产生具有长或短重复区的Vsa蛋白而不是VsaA（VsaG和VsaI）的肺结核菌株表明，对聚苯乙烯的粘附和对补体的抗性取决于重复区的长度，而不是Vsa类型。此外，M。肺吸虫Vsa变异体对多肽成孔分子短杆菌肽D敏感，与Vsa类型和长度无关。总的来说，数据表明Vsa蛋白非特异性介导M。肺支原体表面相互作用和功能是在空间上阻碍补体进入支原体细胞膜，同时允许更小的分子进入。
The Vsa proteins are associated with the virulence of the murine respiratory pathogen Mycoplasma pulmonis. The antigens consist of a conserved N-terminal region that is combined with one of several different variable C-terminal regions comprised of tandem repeats. M. pulmonis strains that produce VsaA with about 40 tandem repeats do not adhere to polystyrene or erythrocytes and are highly resistant to complement killing. Strains that produce VsaA with three tandem repeats adhere strongly to polystyrene and erythrocytes and are highly susceptible to complement killing. We report here that the resistance to complement lysis was not due to a lack of activation of the complement cascade. Isolation and analysis of M. pulmonis strains that produced Vsa proteins other than VsaA (VsaG and VsaI) with either long or short repeat regions indicated that adherence to polystyrene and resistance to complement were dependent on the length of the repeat region but not on the Vsa type. Furthermore, M. pulmonis Vsa variants were susceptible to the polypeptide pore-forming molecule gramicidin D, independent of the Vsa type and length. Collectively, the data indicate the Vsa proteins nonspecifically mediate M. pulmonis surface interactions and function to sterically hinder access of complement to the mycoplasma cell membrane while permitting access of smaller molecules.