An antiserum to a synthetic fimbrial peptide of Actinobacillus actinomycetemcomitans blocked adhesion of the microorganism

Abstract

The purpose of this study is to certify the importance of the fimbriae as an attachment factor of Actinobacillus actinomycetemcomitans, a human periodontopathic bacterium, and the significance of anti-fimbrial antibody function as an attachment inhibitor. Fimbrial antigen was prepared from the A. actinomycetemcomitans 310-a strain. Oligopeptides were synthesized according to the amino acid sequence of the fimbrial protein. The peptide antigen was conjugated with branched lysine polymer resin beads. The peptide antigen was suspended in PBS emulsified with incomplete Freund's adjuvant and used to immunize rabbits. A rabbit antiserum reacted with an approximately 54 kDa protein of the fimbriae protein from A. actinomycetemcomitans 310-a and with those of other fimbriated strains. This antiserum strongly inhibited the attachment of fimbriated A. actinomycetemcomitans strains to saliva-coated hydroxyapatite beads, buccal epithelial cells, and a fibroblast cell line, Gin-1. Such a synthetic fimbrial peptide antigen may be effective in inducing antibodies which inhibit adhesion and subsequent colonization by A. actinomycetemcomitans.

Influence of Aae Autotransporter Protein on Adhesion and Biofilm Formation by Aggregatibacter actinomycetemcomitans

“…The fimbriae are the main structure involved in biofilm formation in rough variants. However, the addition of polyclonal antiserum against a fimbrial peptide has only partially inhibited the adhesion of smooth variants (22), indicating a role of other surface components. It is currently known that fimbriae, lipopolysaccharide (LPS) and extracellular polymeric substance (EPS) play a role in the biofilm formation of A. actinomycetemcomitans and their expression is up regulated by iron limitation and anaerobiosis (23).…”

Heterogeneous Post‐Translational Modification of Actinobacillus actinomycetemcomitans Fimbrillin

“…Bundleforming fimbriae in this bacterium are produced on the cell surface of freshly isolated strains, but not on laboratory subcultured strains (4,10). The fimbriae have been suggested to be involved in adhesion to host tissues such as hydroxyapatite and epithelial cells (2,10). We previously cloned the gene encoding a fimbrial subunit, fimbrillin, from a fresh isolate and analyzed its nucleotide sequence (3).…”

Characterization of Actinobacillus actinomycetemcomitans Hemolysin

“…Several of its virulence factors are currently being studied, including its ability to attach to host tissues, endotoxin, immunosuppressing factors and leukotoxin (6,9,13,19,23,25,30). A. actinomycetemcomitans produces a leukotoxin which may specifically be cytotoxic to human polymorphonuclear leukocytes, monocytes, human leukemic cell lines, and human T and B cell lines (9,18,25,26). However, other human cells such as erythrocytes, platelets, fibroblasts, and endothelial and epithelial cells, as well as rabbit, rat and mouse leukocytes are not susceptible to this leukotoxin (12,19,26).…”