McMillan David J, Davies Mark R, Good Michael F, Sriprakash Kadaba S
The Queensland Institute of Medical Research, Brisbane, QLD, Australia.
FEMS Immunol Med Microbiol. 2004 Apr 9;40(3):249-56. doi: 10.1016/S0928-8244(04)00003-3.
Extracellular localisation of manganese-dependent superoxide dismutase (SodA) by group A streptococcus (GAS) may have a role in protection of this pathogenic bacterium from exogenously produced reactive oxygen species. In this study we show that SodA is found both in surface protein extracts and in culture supernatants of GAS. To investigate whether SodA is a possible vaccine candidate outbred Quackenbush mice were subcutaneously vaccinated with recombinant SodA. Strong antibody responses which were moderately opsonic were elicited. These antibodies were unable to protect mice from intraperitoneal challenge with M1 GAS. We also show that SodA and p145 (a conserved peptide from the M-protein) antibodies are present at significantly higher levels amongst patients with rheumatic heart disease than in control subjects from the same endemic region. The higher SodA antibody levels in patients may be indicative of a role for this protein in pathogenesis of rheumatic heart disease but are more likely to be a marker of recent or recurrent streptococcal infection.
A组链球菌（GAS）对锰依赖性超氧化物歧化酶（SodA）的细胞外定位可能有助于这种病原菌抵御外源性产生的活性氧。在本研究中，我们发现SodA存在于GAS的表面蛋白提取物和培养上清液中。为了研究SodA是否可能是一种疫苗候选物，我们用重组SodA对远交群夸肯布什小鼠进行皮下接种。引发了强烈的抗体反应，且具有中度调理作用。这些抗体无法保护小鼠免受M1 GAS的腹腔攻击。我们还发现，与来自同一流行地区的对照受试者相比，风湿性心脏病患者体内SodA和p145（M蛋白的保守肽段）抗体水平显著更高。患者体内较高的SodA抗体水平可能表明该蛋白在风湿性心脏病发病机制中起作用，但更有可能是近期或复发性链球菌感染的标志物。
