Burova L A, Nagornev V A, Pigarevsky P V, Gladilina M M, Molchanova I V, Gavrilova E A, Totolian A A, Thern A, Schalén C
Institute of Experimental Medicine, Academy of the Medical Sciences, St.Petersburg, Russia.
Indian J Med Res. 2004 May;119 Suppl:183-5.
BACKGROUND & OBJECTIVES: We have earlier proposed that group A streptococcal (GAS) immunoglobulin binding surface proteins (IgGBPs) might trigger anti-IgG production and immune complex formation leading to glomerulonephritis. In the present study, cardiac tissue material from rabbits injected with heat-killed GAS was investigated.
Rabbits were injected intravenously with 10(9) colony forming units of streptococci three times weekly for 8 wk. Cardiac tissue samples were obtained at different times and deposition of IgG, C3, TNF-alpha and IL-6 was studied.
After 8 or more weeks of intravenous (iv) injections, minimal changes were seen in animals receiving an IgG non-binding GAS strain, type T27, whereas in those animals receiving either of two IgG binding GAS strains, types M1 or M22, strong inflammatory and degenerative myocardial changes accompanied by deposition of IgG and C3 were noted. Furthermore, on injecting rabbits with defined mutants of a type M22 strain, the development of myocardial tissue damage proved to be dependent on the presence streptococcal IgGBPs.
INTERPRETATION & CONCLUSION: The present data supported a role of streptococcal IgGBPs in the induction of myocardial tissue injury by GAS.
我们先前曾提出，A 组链球菌（GAS）免疫球蛋白结合表面蛋白（IgGBPs）可能触发抗 IgG 产生及免疫复合物形成，进而导致肾小球肾炎。在本研究中，对注射热灭活 GAS 的家兔心脏组织材料进行了研究。
每周 3 次给家兔静脉注射 10⁹ 个链球菌菌落形成单位，共 8 周。在不同时间获取心脏组织样本，研究 IgG、C3、肿瘤坏死因子-α（TNF-α）和白细胞介素-6（IL-6）的沉积情况。
静脉注射 8 周或更长时间后，接受 IgG 非结合性 GAS 菌株 T27 型的动物未见明显变化，而接受两种 IgG 结合性 GAS 菌株 M1 型或 M22 型之一的动物，出现了强烈的炎症和退行性心肌变化，并伴有 IgG 和 C3 的沉积。此外，给家兔注射 M22 型菌株的特定突变体后，心肌组织损伤的发展被证明依赖于链球菌 IgGBPs 的存在。
目前的数据支持链球菌 IgGBPs 在 GAS 诱导心肌组织损伤中所起的作用。
