Polyadhesins: Anti-Immune Armament of Pathogenic Bacteria

The rapid emergence of new and treatment-resistant Gram-negative bacteria (GNB) has become a major threat to public health. The recent outbreak of new Shiga-toxin–producing E. coli O104H4 infection in Germany illustrates this problem. To colonize host tissues, most pathogenic GNB express surface adhesive organelles. The German strain uses aggregative adherence fimbriae I (AAF/I) to anchor to the intestinal mucosa and induce inflammation. AAF/I belong to the discovered by us family of fimbrial polyadhesins. Polyadhesins of pathogenic GNB are functioning as an armament for hijacking, neutralization and misleading of host immune system. Many fimbrial polyadhesins, including AAF/I, are immunoprotective, which makes them attractive vaccine candidates. Previously, our structural studies suggested a new approach to construction of highly soluble monomeric subunits of fimbrial polyadhesins. This approach facilitates design of potential molecular vaccines against several infectious diseases.