galE mutant of Campylobacter jejuni exhibits a changed lipooligosaccharide structure / 中国免疫学杂志

ABSTRACT

Objective:To explore if galE knock-out mutant of Campylobacter jejuni(CJ) have a changed lipooligosaccharide(LOS) structure.Methods:Lipooligosaccharide from parental strains(CJ HB9313) and mutant strains were isolated and purified.The purified LOS preparations from parental and mutant strains were resolved by Tricine SDS polyacrylamide gel electrophoresis(PAGE),analyzed by silver staining and Western blot,tested for reaction with the ganglioside-binding ligands of cholera toxin(CT).Results:Silver staining showed that the parent strain expressed a LOS molecule of around 5 5 kD,whereas the galE mutant strain expressed a molecule of 4.5 kD.The Western blot showed that the LOS,expressed by galE mutant strain,no longer reacted with antiserum raised against CJ HB9313.Compared with parent strain,the mutant lost reactivity with CT.Conclusion:These results indicate that LOS molecule of galE mutants is truncated and removes epitopes that react with antiserum and ganglioside-like structures.The absence of these structures in the galE mutants may enable the development of a safe,live-vaccine without the possibility of inducing an immune response to host gangliosides.