Recombinant Escherichia coli produces tailor-made biopolyester granules for applications in fluorescence activated cell sorting: functional display of the mouse interleukin-2 and myelin oligodendrocyte glycoprotein

Bäckström, B. Thomas, Brockelbank, Jane A. and Rehm, Bernd H. A. (2007) Recombinant Escherichia coli produces tailor-made biopolyester granules for applications in fluorescence activated cell sorting: functional display of the mouse interleukin-2 and myelin oligodendrocyte glycoprotein. BMC Biotechnology, 7 3.1-3.12. doi:10.1186/1472-6750-7-3


Author Bäckström, B. Thomas
Brockelbank, Jane A.
Rehm, Bernd H. A.
Title Recombinant Escherichia coli produces tailor-made biopolyester granules for applications in fluorescence activated cell sorting: functional display of the mouse interleukin-2 and myelin oligodendrocyte glycoprotein
Journal name BMC Biotechnology   Check publisher's open access policy
ISSN 1472-6750
Publication date 2007-01-04
Sub-type Article (original research)
DOI 10.1186/1472-6750-7-3
Open Access Status DOI
Volume 7
Start page 3.1
End page 3.12
Total pages 12
Place of publication London, UK
Publisher BioMed Central
Language eng
Subject 2700 Medicine
1305 Biotechnology
Formatted abstract
Background: Fluorescence activated cell sorting (FACS) is a powerful technique for the qualitative and quantitative detection of biomolecules used widely in both basic research and clinical diagnostic applications. Beads displaying a specific antigen are used to bind antibodies which are then fluorescently labelled using secondary antibodies. As the individual suspension bead passes through the sensing region of the FACS machine, fluorescent signals are acquired and analysed. Currently, antigens are tediously purified and chemically cross-linked to preformed beads. Purification and coupling of proteins often renders them inactive and they will not be displayed in its native configuration. As an alternative, we genetically engineered Escherichia coli to produce biopolyester (polyhdroxyalkanoate=PHA) granules displaying diagnostically relevant antigens in their native conformation and suitable for FACS analysis.

Results: Hybrid genes were constructed, which encode either the mouse interleukin-2 (IL2) or the myelin oligodendrocyte glycoprotein (MOG) fused via an enterokinase site providing linker region to the C terminus of the PHA granule associated protein PhaP, respectively. The hybrid genes were expressed in PHA-accumulating recombinant E. coli. MOG and IL2 fusion proteins were abundantly attached to PHA granules and were identified by MALDI-TOF/MS analysis and N terminal sequencing. A more abundant second fusion protein of either MOG or IL2 resulted from an additional N terminal fusion, which did surprisingly not interfere with attachment to PHA granule. PHA granules displaying either IL2 or MOG were used for FACS using monoclonal anti-IL2 or anti-MOG antibodies conjugated to a fluorescent dye. FACS analysis showed significant and specific binding of respective antibodies. Enterokinase treatment of IL2 displaying PHA granules enabled removal of IL2 as monitored by FACS analysis. Mice were immunized with either MOG or OVA (ovalbumin) and the respective sera were analysed using MOG-displaying PHA granules and FACS analysis showing a specific and sensitive detection of antigen-specific antibodies within a wide dynamic range.

Conclusion: E. coli can be genetically engineered to produce PHA granules displaying correctly folded eukaryotic proteins and which can be applied as beads in FACS based diagnostics. Since PHA granule formation and protein attachment occurs in one step already inside the bacterial cell, microbial production could be a cheap and efficient alternative to commercial beads.
Keyword Escherichia coli
Interleukin-2
Myelin oligodendrocyte glycoprotein
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: UQ Diamantina Institute Publications
 
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Created: Mon, 19 May 2014, 11:30:01 EST by Jane Mullaney on behalf of UQ Diamantina Institute