Salit I E, Hanley J, Clubb L, Fanning S
Department of Microbiology, University of Toronto, Ontario, Canada.
Infect Immun. 1988 Sep;56(9):2330-5. doi: 10.1128/iai.56.9.2330-2335.1988.
P pilus filaments are important in binding to globoside through an adhesin located at the tip of the pilus. There is considerable antigenic variation among P pili, and the immunologic response is usually serotype specific. We purified denatured pilin subunits and used them as immunogens to prepare more broadly cross-reactive antisera. Although antifilament antisera (AFA) detected predominantly the homologous strain, antisubunit antisera (ASA) prepared from two different strains detected P pili in 16 of 16 and 14 of 16 P-piliated strains by Western blotting (immunoblotting). The binding of ASA to the homologous pilus filament was inhibited by only 3 of 17 strains. ASA agglutinated only two of nine heterologous strains and immunoprecipitated pili from one of three heterologous strains. By immunoelectron microscopy ASA was seen to bind to pilus filaments but not as strongly as AFA. Antiserum raised to the denatured pilin subunit was not substantially more reactive with pilus filaments derived from heterologous strains than was AFA. ASA was, however, a very useful probe for detecting most P pilins.
P菌毛丝通过位于菌毛尖端的黏附素与球苷结合，这一过程非常重要。P菌毛之间存在相当大的抗原变异，免疫反应通常具有血清型特异性。我们纯化了变性菌毛蛋白亚基，并将其用作免疫原以制备更具广泛交叉反应性的抗血清。尽管抗丝抗血清（AFA）主要检测同源菌株，但由两种不同菌株制备的抗亚基抗血清（ASA）通过蛋白质印迹法（免疫印迹法）在16株产P菌毛菌株中的16株以及16株中的14株中检测到了P菌毛。在17株菌株中，只有3株能抑制ASA与同源菌毛丝的结合。ASA仅凝集了9株异源菌株中的2株，并从3株异源菌株中的1株中免疫沉淀出菌毛。通过免疫电子显微镜观察到，ASA能与菌毛丝结合，但结合强度不如AFA。针对变性菌毛蛋白亚基产生的抗血清与来自异源菌株的菌毛丝的反应性并不比AFA强很多。然而，ASA是检测大多数P菌毛蛋白的非常有用的探针。
