Bacterial inclusion bodies as potential synthetic devices for pathogen recognition and a therapeutic substance release

Klaudia Talafová,Dušan Chorvát,Jozef Nahálka,Eva Hrabárová

doi:10.1186/1475-2859-12-16

Abstract

BackgroundAdhesins of pathogens recognise the glycans on the host cell and mediate adherence. They are also crucial for determining the tissue preferences of pathogens. Currently, glyco-nanomaterials provide potential tool for antimicrobial therapy. We demonstrate that properly glyco-tailored inclusion bodies can specifically bind pathogen adhesins and release therapeutic substances.ResultsIn this paper, we describe the preparation of tailored inclusion bodies via the conjugation of indicator protein aggregated to form inclusion bodies with soluble proteins. Whereas the indicator protein represents a remedy, the soluble proteins play a role in pathogen recognition. For conjugation, glutaraldehyde was used as linker. The treatment of conjugates with polar lysine, which was used to inactivate the residual glutaraldehyde, inhibited unwanted hydrophobic interactions between inclusion bodies. The tailored inclusion bodies specifically interacted with the SabA adhesin from Helicobacter pylori aggregated to form inclusion bodies that were bound to the sialic acids decorating the surface of human erythrocytes. We also tested the release of indicator proteins from the inclusion bodies using sortase A and Ssp DNAB intein self-cleaving modules, respectively. Sortase A released proteins in a relatively short period of time, whereas the intein cleavage took several weeks.ConclusionsThe tailored inclusion bodies are promising “nanopills” for biomedical applications. They are able to specifically target the pathogen, while a self-cleaving module releases a soluble remedy. Various self-cleaving modules can be enabled to achieve the diverse pace of remedy release.

Highlights

Adhesins of pathogens recognise the glycans on the host cell and mediate adherence
Preparation and testing of tailored inclusion bodies (IBs) The first step in our work was the preparation of IBsconjugates representing “nanopills” composed of green fluorescent protein (GFP)-containing IBs and soluble proteins using glutaraldehyde as linker
We used SabA lectin from the bacterium Helicobacter pylori in the form of IBs that is responsible for the in vitro agglutination of erythrocytes. Because this interaction is dependent on the sialic acid (Sia)-terminated oligosaccharides, it can be modified by sialylated proteins [20], e.g., GFP aggregated to form IBs (gfpIBs)-fetuin conjugates

Summary

Introduction

Adhesins of pathogens recognise the glycans on the host cell and mediate adherence. The glycan chains that decorate cell surfaces mediate various normal and pathological processes They are responsible for host-pathogen interactions, as they are used by various viruses, bacteria and parasites to promote the pathogenesis. The idea has been proposed that the glycoengineering of cell surfaces or the development of specific glyco-nanomaterials will provide new tools for the therapeutic targeting of pathogenic or cancer cells [6,7]. IBs are insoluble proteinaceous aggregates commonly observed in bacterial cells during the over-expression of recombinant genes They have usually been considered to be waste byproducts formed by unfolded or misfolded and biologically inactive polypeptides [8]. Their biological origin, mechanical stability and regulatable size make IBs suitable nanomaterials for biomedicine [8]

Objectives

Methods

Results

Discussion

Conclusion