Mintz C S, Zou C H
Department of Microbiology and Immunology, University of Miami School of Medicine, FL 33101.
FEMS Microbiol Lett. 1992 Jun 15;72(3):249-53. doi: 10.1016/0378-1097(92)90470-9.
A mutant unable to bind a monoclonal antibody (mAb 1E6) directed against serogroup 1 lipopolysaccharide (LPS) was isolated from L. pneumophila strain Philadelphia-1. SDS-PAGE analysis of isolated LPS from the mutant and wild type revealed that there were no obvious structural differences between the two LPS. The results from Western-blot experiments showed that the mutant LPS was unable to bind mAb 1E6 but retained the ability to bind polyclonal serogroup 1 antibodies. Loss of the LPS epitope recognized by mAb 1E6 did not alter the ability of the mutant to multiply in human monocyte-like U937 cells. Also, the mutant, like wild type, was resistant to killing by normal human serum. These results show that a minor change in the antigenic composition of serogroup 1 LPS has no effect on the virulence properties of strain Philadelphia-1. Additionally, this mutant may be useful for molecular genetic analysis of serogroup 1 LPS biosynthesis and assembly.
从嗜肺军团菌费城 -1菌株中分离出一株无法结合针对1型血清群脂多糖（LPS）的单克隆抗体（mAb 1E6）的突变体。对突变体和野生型分离出的LPS进行SDS - PAGE分析表明，两种LPS之间没有明显的结构差异。蛋白质印迹实验结果显示，突变体LPS无法结合mAb 1E6，但保留了结合1型血清群多克隆抗体的能力。mAb 1E6识别的LPS表位的缺失并未改变突变体在人单核细胞样U937细胞中增殖的能力。此外，该突变体与野生型一样，对正常人血清杀伤具有抗性。这些结果表明，1型血清群LPS抗原组成的微小变化对费城 -1菌株的毒力特性没有影响。此外，该突变体可能有助于对1型血清群LPS生物合成和组装进行分子遗传学分析。
