Attaching substances to microorganisms

Abstract

The invention relates to surface display of proteins on microorganisms via the targeting and anchoring of heterologous proteins to the outer surface of cells such as yeast, fungi, mammalian, plant cells, and bacteria. The invention provides a proteinaceous substance comprising a reactive group and at least one attaching peptide including a stretch of amino acids having a sequence corresponding to at least a part of the consensus amino acid sequence listed in FIG. 10 and further includes a method for attaching a proteinaceous substance to the cell wall of a microorganism comprising the use of the attaching peptide.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a divisional of U.S. Ser. No. 09 / 554,354, filed May 12, 2000, which is a national entry of PCT International Patent Application No. PCT / NL98 / 00655, filed on Nov. 12, 1998, (corresponding to PCT International Publication No. WO 99 / 25836, the contents of which is incorporated by this reference as is the sequence listing in U.S. Ser. No. 09 / 554,354).TECHNICAL FIELD [0002] The invention relates to surface display of proteins on microorganisms via the targeting and anchoring of heterologous proteins to the outer surface of cells such as yeast, fungi, mammalian, plant cells, and bacteria. BACKGROUND [0003] Heterologous surface display of proteins (Stahl and Uhlen, TIETECH May 1997, 15, 185-192) on recombinant microorganisms via the targeting and anchoring of heterologous proteins to the outer surface of host-cells such as yeast, fungi, mammalian and plant cells, and bacteria has been possible for several years. Display of h...

AI Technical Summary

Benefits of technology

[0012] For example, the invention provides a substance wherein the reactive group is a non-protein moiety, for example, is selected from the group of antibiotics, hormones, aromatic substances and reporter molecules. The substance is constructed by binding, for example, an antibiotic, such as penicillin or tetracycline, but various other antibiotics can be used, or a hormone, such as a steroid hormone, or any other compound to an attaching peptide provided by the invention. Such binding can be achieved by various techniques known in the art, and thereby can label or “flag” the attaching peptide. A preferred example is the binding of an attaching peptide to a reporter molecule such as FITC, or HRPO, whereby tools are generated that can be used in diagnostic assay whereby microorganisms having peptidoglycan are detected. Similarly, an attaching peptide with an antibiotic bound thereto can be used in vivo by, for example, parenteral administration into the bloodstream of humans or animals or in vitro to bind to such microorganisms having peptidoglycan, thereby increasing the concentration of antibiotic around the organism, which then gets killed by the antibiotic action.

[0017] The invention provides a method for attaching a substance to the cell wall of a microorganism comprising the use of an attaching peptide which comprises a stretch of amino acids having a sequence corresponding to at least a part of the consensus amino acid sequence provided in FIG. 10. An example of the method provided by the invention is anchoring of recombinant (poly)peptides, being (chimeric) proteins fused to the cell wall-anchoring repeats of AcmA of Lactococcus lactis MG1363 or to the cell wall of gram-positive bacteria. The recombinant proteins are obtained by the expression of DNA sequences encoding these recombinant (poly)peptides in a suitable production strain (e.g. E. coli or L. lactis) and subsequent purification of the expression products. The recombinant proteins are then mixed, either in vitro or in vivo, with a non-recombinant target bacterium to obtain binding to the cell wall. Another example of the method provided by the invention is anchoring of recombinant (poly)peptides, being (chimeric) proteins fused to the cell wall anchoring repeats of AcmA of Lactococcus lactis, to the cell wall of the recombinant Lactococcus lactis which produces the protein itself. A preferred embodiment of the method provided by the invention, the binding of (purified) proteins to bacterial cells upon addition from the outside, is an excellent tool to anchor recombinant proteins or other substances to non-recombinant bacterial cells.

Problems solved by technology

A drawback to this approach is the potential of the bacterial strain to cause inflammation and disease in itself, potentially leading to fever and bacteraemia.

However, a potential problem with such recombinant organisms is that they may colonize the mucosal surfaces, thereby generating a long-term exposure to the target antigens expressed and released by these recombinant microorganisms.

In addition, the mere fact alone that such organisms are genetically modified and contain recombinant nucleic acid is meeting considerable opposition from the lay public as a whole, stemming from a low level of general acceptance for products containing recombinant DNA or RNA.

However, as explained above, present techniques of heterologous surface display of proteins in general entail the use of anchoring or targeting proteins that are specific and selective for a limited set of microorganisms which in general are of recombinant or pathogenic nature, thereby greatly restricting their potential applications.

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