Modulating bacterial and gut mucosal interactions with engineered biofilm matrix proteins

Anna M Duraj-Thatte,Pichet Praveschotinunt,Neel S Joshi,Trevor R Nash,Peter Q Nguyen,Frederick R Ward

doi:10.1038/s41598-018-21834-8

Anna M Duraj-Thatte, Pichet Praveschotinunt + Show 4 more

Open Access

https://doi.org/10.1038/s41598-018-21834-8

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Journal: Scientific Reports	Publication Date: Feb 22, 2018
Citations: 26	License type: open-access

Affiliation: Harvard University

Abstract

Extracellular appendages play a significant role in mediating communication between bacteria and their host. Curli fibers are a class of bacterial fimbria that is highly amenable to engineering. We demonstrate the use of engineered curli fibers to rationally program interactions between bacteria and components of the mucosal epithelium. Commensal E. coli strains were engineered to produce recombinant curli fibers fused to the trefoil family of human cytokines. Biofilms formed from these strains bound more mucins than those producing wild-type curli fibers, and modulated mucin rheology as well. When treated with bacteria producing the curli-trefoil fusions mammalian cells behaved identically in terms of their migration behavior as when they were treated with the corresponding soluble trefoil factors. Overall, this demonstrates the potential utility of curli fibers as a scaffold for the display of bioactive domains and an untapped approach to rationally modulating host-microbe interactions using bacterial matrix proteins.

Highlights

Extracellular appendages play a significant role in mediating communication between bacteria and their host
We have previously shown that the main structural component of curli fibers, CsgA, can be fused to a range of heterologous domains without abolishing its ability to be secreted and assembled extracellularly[15]
In order to enhance the interaction of curli nanofibers with the gut mucosa, we genetically fused CsgA to the trefoil factors (TFF1, TFF2, and TFF3), a family of human cytokines that are secreted by mucus-producing cells and goblet cells into the gut lumen and contribute to the maintenance of homeostasis (Figure S1)

Summary

Introduction

Extracellular appendages play a significant role in mediating communication between bacteria and their host. When treated with bacteria producing the curli-trefoil fusions mammalian cells behaved identically in terms of their migration behavior as when they were treated with the corresponding soluble trefoil factors Overall, this demonstrates the potential utility of curli fibers as a scaffold for the display of bioactive domains and an untapped approach to rationally modulating host-microbe interactions using bacterial matrix proteins. The mucosal surfaces of the gastrointestinal (GI) tract serve several important protective functions, including lubricating the epithelium, decreasing the shear forces experienced by its constituent cells, and trapping debris and bacteria[1] They do this, in part, through the formation of a microporous gel-like mucus layer composed of proteoglycans (i.e. mucins) that are secreted by the epithelial cells. We show that we can program such a matrix to display specific protein domains that function simultaneously to enhance adhesion to mucins and epithelial cell surfaces, and modify cell behavior

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Conclusion