Antigenic and immunogenic differences in lipopolysaccharides of Escherichia coli J5 vaccine strains of different origins

Abstract

Escherichia coli strain J5 mutants of various origins have often been used as vaccines for induction of crossreactive, cross-protective antibodies directed against the lipopolysaccharide (LPS) core region. The antigenic composition of LPS from J5 strains of different origin, i.e. strains J5(U), J5(UK), J5(2877) and J5(a), was investigated using monoclonal antibodies (mAbs) reactive only with LPS of a given chemotype, i.e. one specific for the incomplete E. coli core of the Rc chemotype, a second mAb reactive only with the E. coli R3 complete core, and a third specific for the 0-antigen of E. coli serovar 0111. The LPS of strains J 5 0 and J5(a) is almost exclusively composed of LPS of the Rc chemotype, LPS of the J5(UK) strain is composed of Rc LPS and R3 complete core, while LPS of the J5(2877) strain contains Rc, R3 complete core and 0-antigen. Growth of the bacteria in medium supplemented with galactose led to increased expression of complete core. The immune responses to the various strains were investigated. Antiserum to the J5 strain expressing the largest amount of R3 core [J5(UK)] had much higher anti-R3 LPS antibody titres compared to antiserum to the other strains. mAb 53, representative of the anti-R3 response to J5 strains containing complete core, bound to those E. coli LPS expressing the R3 core. Thus, the R3 LPS, present in some J5 vaccine strains is at least partially responsible for some of the cross-reactivities exhibited by some anti-J5 antisera. The present findings may explain some of the discrepant outcomes reported for cross-protection studies with J5 antisera, where J5 strains of various origins grown under different culture conditions have been used as vaccines and where LPS or bacteria expressing various core types have been used for challenge.

Chromosomal and Plasmid-encoded Enzymes Are Required for Assembly of the R3-type Core Oligosaccharide in the Lipopolysaccharide of Escherichia coli O157:H7

“…The R3 core type is also found in E. coli J5, a mutant with rough LPS (i.e. devoid of O-PS) originally isolated from E. coli O111:B4 (15). The J5 LPS has been widely used in immunochemical studies, in analyses of endotoxicity, and in attempts to develop antibodies against core OS-lipid A that would be broadly cross-reactive and protective in applications such as treatment of sepsis (15)(16)(17)(18)(19).…”

“…devoid of O-PS) originally isolated from E. coli O111:B4 (15). The J5 LPS has been widely used in immunochemical studies, in analyses of endotoxicity, and in attempts to develop antibodies against core OS-lipid A that would be broadly cross-reactive and protective in applications such as treatment of sepsis (15)(16)(17)(18)(19). Antibodies cross-reacting with R3 core OS epitopes were detected in 6 of 10 patients infected with different EHEC strains (20), and it has been proposed that IgG and IgA responses to the R3 core OS may be protective against E. coli and Shigella spp.…”

Development of an Immunoassay for Rapid Detection of Ganglioside GM 1 Mimicry in Campylobacter jejuni Strains

“…Gangliosides (1-g aliquots; Sigma) and LPS extracts (5-l aliquots) were analyzed by TLC on precoated silica gel 60 glass plates (Merck, Darmstadt, Germany). Solvent systems consisting of chloroform-methanol-0.22% CaCl 2 (49,59) were used as developers for gangliosides and LPSs, respectively. Gangliosides and LPS were visualized by spraying plates with resorcinolHCl reagent (50).…”

Complement‐mediated lipopolysaccharide release and outer membrane damage in Escherichia coli J5: requirement for C9

“…In the absence of galactose, most E. coli J5 strains produce rough‐form LPS, whereas in the presence of galactose a smooth‐form LPS, apparently identical to that of the parent strain, is produced 26 . Antigenic studies using monoclonal antibodies (mAbs) reactive with LPS of Rc (incomplete core) or R3 (complete core) core chemotypes, have revealed differences between the LPS of E. coli J5 strains 27 …”