DAF- and collagen-binding properties of chimeric Dr fimbriae

Abstract

Display of heterologous proteins on the surface of micro-organisms has become an increasingly used strategy for a range of applications in microbiology, biotechnology and vaccinology. In this study, the potential of the major structural protein DraE of Escherichia coli Dr fimbriae as a display system for heterologous sequences was tested. One copy of a heterologous sequence mimicking a small P k epitope of simian virus 5 was inserted into the draE gene, replacing the N-terminal region of the surface-exposed domain 2 as previously done with the glycoprotein D of herpes simplex virus type 1. The exposure of chimeric proteins on the bacterial surface was detected by immunofluorescence microscopy. Insertion of the heterogenic peptides had no detectable effect on the Ig-barrel structure of the DraE fimbrial subunits, as confirmed by FTIR spectroscopy. Additionally, the affinity of the chimeric fimbriae for DAF and type IV collagen was similar to that of the wild-type Dr fimbriae.

Enteroaggregative E. coli Adherence to Human Heparan Sulfate Proteoglycans Drives Segment and Host Specific Responses to Infection

“…Our data suggest that EAEC may interact with ECM proteins via their association with HSPGs, possibly including fibronectin as a co-complex. Since many bacterial pathogens have been reported to interact with ECM proteins, it will now be necessary to determine if HSPGs are a component of these interactions [ 72 , 93 – 95 ].…”

Mecanismos de virulencia de Escherichia coli enteropatógena

“…hDAF es una glicoproteína de 70 KDa que se encuentra distribuida en todas las células de la sangre, en el epitelio del intestino, tracto genito-urinario y células endoteliales. Tiene como función regular la cascada del complemento en el paso de la convertasa C3, cumple un papel importante en la interacción entre el patógeno y las células del hospedero para favorecer la infección 126 .…”

The Major Pilin Subunit of the AAF/II Fimbriae from Enteroaggregative Escherichia coli Mediates Binding to Extracellular Matrix Proteins

“…The biogenesis of AAFs employs the chaperone-usher pathway, and the organization of AAF-encoding genes is similar to those of the Afa/Dr family of E. coli adhesins; this organization comprises, in order, chaperone, usher, minor pilin subunit, and major pilin subunit (26). The Afa/Dr adhesins bind to several receptors, including decay-accelerating factor (DAF), as well as extracellular matrix (ECM) proteins, particularly type IV collagen (35).…”