Wang E, Garcia M M, Blake M S, Pei Z, Blaser M J
Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
J Bacteriol. 1993 Aug;175(16):4979-84. doi: 10.1128/jb.175.16.4979-4984.1993.
Campylobacter fetus strains possess regular paracrystalline surface layers (S-layers) composed of high-molecular-weight proteins and can change the size and crystalline structure of the predominant protein expressed. Polyclonal antisera demonstrate antigenic cross-reactivity among these proteins but suggest differences in epitopes. Monoclonal antibodies to the 97-kDa S-layer protein of Campylobacter fetus subsp. fetus strain 82-40LP showed three different reactivities. Monoclonal antibody 1D1 recognized 97-kDa S-layer proteins from all C. fetus strains studied; reactivity of monoclonal antibody 6E4 was similar except for epitopes in S-layer proteins from reptile strains and strains with type B lipopolysaccharide. Monoclonal antibody 2E11 only recognized epitopes on S-layer proteins from strains with type A lipopolysaccharide regardless of size. In vitro shift from a 97-kDa S-layer protein to a 127-kDa S-layer protein resulted in different reactivity, indicating that size change was accompanied by antigenic variation. To examine in vivo variation, heifers were genetically challenged with Campylobacter fetus subsp. venerealis strains and the S-layer proteins from sequential isolates were characterized. Analysis with monoclonal antibodies showed that antigenic reactivities of the S-layer proteins were varied, indicating that these proteins represent a system for antigenic variation.
胎儿弯曲杆菌菌株具有由高分子量蛋白质组成的规则的准晶体表面层（S层），并且可以改变所表达的主要蛋白质的大小和晶体结构。多克隆抗血清显示这些蛋白质之间存在抗原交叉反应，但表明表位存在差异。针对胎儿弯曲杆菌亚种82 - 40LP的97 kDa S层蛋白的单克隆抗体表现出三种不同的反应性。单克隆抗体1D1识别所有所研究的胎儿弯曲杆菌菌株的97 kDa S层蛋白；单克隆抗体6E4的反应性相似，但来自爬行动物菌株和具有B型脂多糖的菌株的S层蛋白中的表位除外。单克隆抗体2E11仅识别来自具有A型脂多糖的菌株的S层蛋白上的表位，而不考虑大小。在体外从97 kDa S层蛋白转变为127 kDa S层蛋白导致不同的反应性，表明大小变化伴随着抗原变异。为了研究体内变异，用胎儿弯曲杆菌亚种性病菌株对小母牛进行基因攻击，并对连续分离株的S层蛋白进行表征。用单克隆抗体分析表明，S层蛋白的抗原反应性各不相同，表明这些蛋白质代表了一个抗原变异系统。
