Center of Excellence for Vaccine Research, Department of Pathobiology and Veterinary Science, University of Connecticut, 61 N. Eagleville Rd., Storrs, CT 06269, USA.
Infect Immun. 2010 Aug;78(8):3475-83. doi: 10.1128/IAI.00154-10. Epub 2010 Jun 1.
Many lipoproteins are expressed on the surfaces of mycoplasmas, and some have been implicated as playing roles in pathogenesis. Family 2 lipoproteins of Mycoplasma pneumoniae have a conserved "mycoplasma lipoprotein X" central domain and a "mycoplasma lipoprotein 10" C-terminal domain and are differentially expressed in response to environmental conditions. Homologues of family 2 lipoproteins are Mycoplasma specific and include the lipoprotein of Mycoplasma gallisepticum, encoded by the MGA0674 gene. Comparative transcriptomic analysis of the M. gallisepticum live attenuated vaccine strain F and the virulent strain R(low), reported in this study, indicated that MGA0674 is one of several differentially expressed genes. The MGA0674-encoded lipoprotein is a proteolytically processed, immunogenic, TX-114 detergent-phase protein which appears to have antigenic divergence between field strains R(low) and S6. We examined the virulence of an R(low) Delta MGA0674 mutant (P1H9) in vivo and observed reduced recovery and attenuated virulence in the tracheas of experimentally infected chickens. The virulence of two additional R(low) Delta MGA0674 mutants, 2162 and 2204, was assessed in a second in vivo virulence experiment. These mutants exhibited partial to complete attenuation in vivo, but recovery was observed more frequently. Since only Mycoplasma species harbor homologues of MGA0674, the gene product has been renamed "Mycoplasma-specific lipoprotein A" (MslA). Collectively, these data indicate that MslA is an immunogenic lipoprotein exhibiting reduced expression in an attenuated strain and plays a role in M. gallisepticum virulence.
许多脂蛋白在支原体表面表达，其中一些与发病机制有关。肺炎支原体家族 2 脂蛋白具有保守的“支原体脂蛋白 X”中心结构域和“支原体脂蛋白 10”C 末端结构域，并对环境条件表现出差异表达。家族 2 脂蛋白的同源物是支原体特异性的，包括禽支原体的脂蛋白，由 MGA0674 基因编码。本研究报道了对活减毒疫苗株 F 和毒力株 R(low)的比较转录组分析，表明 MGA0674 是几个差异表达基因之一。MGA0674 编码的脂蛋白是一种经蛋白水解处理的、免疫原性的 TX-114 去污剂相蛋白，似乎在现场菌株 R(low)和 S6 之间具有抗原分化。我们在体内研究了 R(low)Delta MGA0674 突变体（P1H9）的毒力，观察到在实验感染鸡的气管中恢复减少和毒力减弱。在第二个体内毒力实验中评估了另外两个 R(low)Delta MGA0674 突变体 2162 和 2204 的毒力。这些突变体在体内表现出部分至完全衰减，但恢复的情况更为频繁。由于只有支原体物种具有 MGA0674 的同源物，因此该基因产物已被重新命名为“支原体特异性脂蛋白 A”（MslA）。综上所述，这些数据表明 MslA 是一种免疫原性脂蛋白，在减毒菌株中表达减少，在禽支原体毒力中发挥作用。
