Arala-Chaves M P, Higerd T B, Porto M T, Munoz J, Goust J M, Fudenberg H H, Loadholt C B
J Clin Invest. 1979 Oct;64(4):871-83. doi: 10.1172/JCI109553.
Products secreted by Streptococcus intermedius were studied for their effects on the immune response. Three different preparations of crude extracellular products from S. intermedius (CEP-Si) were found to have powerful suppressor activity in vitro as shown by inhibition of human lymphocyte proliferation (uptake of [3H]thymidine) and protein synthesis in response to a wide variety of stimulants, including mitogens and antigens, and suppression of plaque formation by human cells in response to sheep erythrocytes. CEP-Si was noncytotoxic, because cells incubated with high concentrations of CEP-Si and subsequently washed were viable and recovered their ability to respond to mitogens, and because leukocyte migration was not inhibited by CEP-Si, nor was the release of leukocyte migration inhibitory factor from sensitized lymphocytes. The possibility of antigen or mitogen competition was excluded. The effects of CEP-Si in vitro were time dependent and did not require the presence of monocytes. Cells pretreated with CEP-Si and then washed suppressed plaque formation by fresh autologous cells in highly stimulated cultures. CEP-Si injected into C57BL/6 mice also strongly suppressed their immune response to sheep erythrocytes, and the in vivo suppression was correlated with the effects of CEP-Si in vitro.
对中间型链球菌分泌的产物进行了研究，以观察其对免疫反应的影响。研究发现，三种不同的中间型链球菌粗细胞外产物制剂（CEP-Si）在体外具有强大的抑制活性，表现为抑制人类淋巴细胞增殖（[3H]胸腺嘧啶核苷摄取）以及对多种刺激物（包括丝裂原和抗原）的蛋白质合成反应，同时抑制人类细胞对绵羊红细胞的噬斑形成。CEP-Si无细胞毒性，因为与高浓度CEP-Si孵育后再洗涤的细胞仍具有活力，且恢复了对丝裂原的反应能力，还因为CEP-Si不抑制白细胞迁移，也不抑制致敏淋巴细胞释放白细胞迁移抑制因子。排除了抗原或丝裂原竞争的可能性。CEP-Si在体外的作用具有时间依赖性，且不需要单核细胞的存在。用CEP-Si预处理然后洗涤的细胞，在高度刺激的培养物中可抑制新鲜自体细胞的噬斑形成。注入C57BL/6小鼠体内的CEP-Si也强烈抑制了它们对绵羊红细胞的免疫反应，且体内抑制作用与CEP-Si在体外的作用相关。
