Fikrig E, Liu B, Fu L L, Das S, Smallwood J I, Flavell R A, Persing D H, Schoen R T, Barthold S W, Malawista S E
Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8031, USA.
J Immunol. 1995 Dec 15;155(12):5700-4.
Passive immunization with murine or human Abs to outer surface protein A (OspA) can protect mice against Borrelia burgdorferi, but OspA Abs elicited during natural infection in mice or humans are unable to clear the spirochete from the infected host. To examine Ab binding by OspA during the course of human infection, we amplified the operon encoding full-length ospA and ospB from synovial fluids of a patient with chronic Lyme arthritis, the first such recoveries from human material, at four separate time points over 4.5 mo, and expressed OspA in Escherichia coli. OspA mAbs that passively protected mice from infection did not bind one of the expressed OspAs, because of a deletion in ospA that resulted in a frame shift and premature stop codon near the carboxyl terminus. However, expressed OspA from a later synovial fluid sample did not contain this deletion. Thus, although altered forms of OspA, which potentially can influence host immune effectiveness, do occur in the human host, they cannot be the only factors responsible for microbial persistence.
用鼠源或人源抗外表面蛋白A（OspA）抗体进行被动免疫可保护小鼠免受伯氏疏螺旋体感染，但在小鼠或人类自然感染过程中产生的OspA抗体无法从受感染宿主中清除螺旋体。为了研究人类感染过程中OspA与抗体的结合情况，我们从一名慢性莱姆关节炎患者的滑液中扩增了编码全长ospA和ospB的操纵子，这是首次从人体材料中获得此类扩增，在4.5个月的四个不同时间点进行，并在大肠杆菌中表达OspA。能被动保护小鼠免受感染的OspA单克隆抗体不与其中一种表达的OspA结合，因为ospA发生了缺失，导致羧基末端附近出现移码和提前终止密码子。然而，后来一份滑液样本中表达的OspA并不包含这种缺失。因此，虽然在人类宿主中确实会出现可能影响宿主免疫效果的OspA变异形式，但它们不可能是微生物持续存在的唯一因素。
