Location of epitopes on Campylobacter jejuni flagella

Abstract

Flagella were isolated from strains of Campylobacterjejuni belonging to different heat-labile serogroups and from a strain of Campylobacter fetus, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the flagellin molecular weights (Mr) were approximately 62,000. The flagellins were cleaved by hydrolysis with cyanogen bromide, and sodium dodecyl sulfate-urea peptide gel electrophoresis showed that the C. jejuni flagellins were structurally similar, and differed from C. fetus flageUin. Immunochemical analysis by Western blotting, enzyme-linked immunosorbent assay, immune electron microscopy, and immunoprecipitation with polyclonal and monoclonal antibodies revealed the presence of both internal and surface-exposed epitopes. The internal epitopes were antigenically cross-reactive and linear, and in the case of C. jejuni flagellin were located on cyanogen bromide peptides of apparent Mr 22,400 and 11,000. Antigenically cross-reactive epitopes were also present on an Mr 43,000 cyanogen bromide peptide of C. fetus flageilin. The Mr 22,400 peptide of C. jejuni VC74 flageilin also carried closely positioned internal linear epitopes for two monoclonal antibodies. One epitope was strain specific, while the other was shared by some but not all Campylobacter flageilins. The flagella of C. jejuni VC74 also displayed both surface-exposed antigenically cross-reactive and surface-exposed serospecific epitopes. Both linear and conformational epitopes contributed to the serospecificity of C. jejuni VC74 flagella, and a linear serospecific epitope was located on a cyanogen bromide peptide of apparent Mr 4,000.

Identification of a common enterobacterial flagellin epitope with a monoclonal antibody

“…This suggests that the epitope reported by is most likely an internal epitope that only becomes accessible to antibody under denaturing conditions. Similar results were obtained in the analysis of Campylobacter flagella, where the conserved or broadly cross-reactive epitopes were predominantly internal and only immunoreactive after denaturation (Harris et al, 1987;Logan & Trust, 1986). The results of our studies suggest that the epitope for mAb 15D8 is probably surface exposed and linear, since antibody reactivity to enterobacterial flagella was obtained with either undenatured flagellar protein (ELISA) or with SDS-denatured antigen (immunoblots).…”

Variation in antigenicity and molecular weight of Campylobacter coli VC167 flagellin in different genetic backgrounds

“…Antigenic diversity also occurs in the case of Campylobacter flagella (20,37). Consistent with the structural model for flagellin presented above, studies at the genetic level by Thornton et al (54) have shown that serotype-specific DNA probes can be constructed by using the central area of the Campylobacter flagellin coding region.…”

Cloning, nucleotide sequence, and taxonomic implications of the flagellin gene of Roseburia cecicola

“…Similarity can be seen in the NH2-terminal and COOH-terminal regions but not in the central region of the sequence. From amino acids 28 to 117, R. cecicola has (8) (3,5,8,10,11,20 (8,12,26). Recent data from Homma et al indicate that in S. typhimurium the flagellin may be in a hairpin configuration with both the NH2 terminus and COOH terminus toward the interior of the flagellin filament, implying a structural role for the termini in filament assembly (7).…”