Mitov I, Freudenberg M, Bamberger U, Galanos C
Max-Planck-Institut für Immunbiologie, Freiburg, Germany.
Immunobiology. 1993 Jun;188(1-2):1-12. doi: 10.1016/S0171-2985(11)80482-1.
Six hybridoma clones (1M, 4M, 9M, 11M, 18M and 31G), secreting monoclonal antibodies (mAbs) against lipid A were obtained after fusion between cells of mouse myeloma line X63-Ag8.653 and spleen cells from BALB/c mice immunized with acid treated Salmonella minnesota bacteria coated with additional free lipid A. The specificity and cross-binding activity of the mAbs were characterized in ELISA by using synthetic lipid A analogs as well as different lipid A and lipopolysaccharides (LPS) extracted from R- and S-form bacteria. It was found that the antibodies recognize epitopes in which phosphate groups, especially those at the C4' position of the glucosamine backbone of lipid A, were present. These epitopes were accessible also for the antibodies in purified intact LPS. By using a set of core glycolipids with increasing completion of the core region of the molecule and S-LPSs it was shown that the mAbs cross-reacted with a variety of R- and S-form LPS. The binding activity decreased with increasing length of the polysaccharide chain. The mAb did not prevent ultimate lethality of mice challenged with Klebsiella pneumoniae B and Salmonella typhimurium C5. However a delay of mortality rate of mice pretreated with antibodies 18M and 31G and infected with K. pneumoniae was seen.
通过小鼠骨髓瘤细胞系X63-Ag8.653的细胞与用额外游离脂质A包被的经酸处理的明尼苏达沙门氏菌免疫的BALB/c小鼠的脾细胞融合，获得了六个分泌抗脂质A单克隆抗体（mAb）的杂交瘤克隆（1M、4M、9M、11M、18M和31G）。通过使用合成脂质A类似物以及从R型和S型细菌中提取的不同脂质A和脂多糖（LPS），在ELISA中对mAb的特异性和交叉结合活性进行了表征。发现这些抗体识别存在磷酸基团的表位，特别是脂质A氨基葡萄糖主链C4'位置的磷酸基团。在纯化的完整LPS中，这些表位也能被抗体识别。通过使用一组核心糖脂，其分子核心区域的完成度逐渐增加，以及S-LPS，结果表明mAb与多种R型和S型LPS发生交叉反应。结合活性随着多糖链长度的增加而降低。mAb不能阻止感染肺炎克雷伯菌B和鼠伤寒沙门氏菌C5的小鼠最终死亡。然而，观察到用抗体18M和31G预处理并感染肺炎克雷伯菌的小鼠死亡率有所延迟。
