Inman R D, Redecha P B, Knechtle S J, Schned E S, van de Rijn I, Christian C L
J Clin Invest. 1982 Aug;70(2):271-80. doi: 10.1172/jci110614.
The presence of circulating immune complexes (IC) in patients with infective endocarditis has been well documented but the contributions of host and bacterial components to these IC have not been defined. To study this question, IC were isolated from serum of a patient with Streptococcus faecalis endocarditis by differential polyethylene glycol precipitation and competitive binding to staphylococcal protein A. A rabbit antiserum raised against the purified IC had reactivity by crossed immunoelectrophoresis primarily with an antigen derived from the cytoplasm of the infective organism. The antigen was a protein with a 12,000-dalton molecular mass. In situ radiolabeling of the IC bound to the protein A demonstrated a component of the same molecular mass as the bacterial antigen recognized by the antiserum. The patient serum had multiple antibody specificities reactive with bacterial antigens, including the antigen recognized by the rabbit anti-IC antiserum. These techniques for isolation and characterization of circulating IC may have value in the study of IC diseases in which the inciting antigens are not known.
感染性心内膜炎患者循环免疫复合物（IC）的存在已有充分记录，但宿主和细菌成分对这些IC的作用尚未明确。为研究此问题，通过差示聚乙二醇沉淀法及与葡萄球菌蛋白A的竞争性结合，从一名粪肠球菌心内膜炎患者的血清中分离出IC。用纯化的IC免疫家兔产生的抗血清，经交叉免疫电泳显示主要与一种源自感染生物体细胞质的抗原发生反应。该抗原是一种分子量为12,000道尔顿的蛋白质。与蛋白A结合的IC的原位放射性标记显示，有一个与抗血清识别的细菌抗原分子量相同的成分。患者血清具有多种与细菌抗原反应的抗体特异性，包括兔抗IC抗血清识别的抗原。这些用于分离和鉴定循环IC的技术，可能在研究病因抗原不明的IC疾病中有价值。
