Group a Streptococcus Crge Protein
The invention provides methods of screening utilising the CrgE protein and the Streptococcus pyogenes bacterium expressing crgE. The invention also provides bacteria where the crgR and/or the crgE gene has been knocked out. The invention also provides fusion proteins comprising the polypeptide encoded by Spy1542 (crgE) and pharmaceutical compositions comprising CrgE.
1 . A Streptococcus bacterium in which expression of CrgE and/or CrgR has been knocked out.
2 . A bacterium according to claim 1 , wherein said bacterium is Streptococcus pyogenes.
3 . A polypeptide comprising the amino acid sequence of SEQ ID NO: 2 or SEQ ID NO: 4.
4 . A polypeptide comprising an amino acid sequence: (a) having sequence identity to an amino acid sequence selected from SEQ ID NO: 2 or SEQ ID NO: 4 and/or (b) comprising a fragment of an amino acid sequence selected from SEQ ID NO: 2 or SEQ ID NO: 4.
5 . A fusion protein comprising a CrgE or CrgR polypeptide.
6 . A mutant CrgE polypeptide that cannot bind its substrate.
7 . (canceled)
8 . A method of preventing and/or treating graft rejection comprising administering CrgE polypeptide to a subject at risk for graft rejection.
9 . (canceled)
10 . A method of enhancing the immune response to a viral vaccine comprising administering CrgE as an adjuvant.
11 . A method of enhancing vaccination comprising administering a composition comprising a vaccine and CrgE to a subject.
12 . A process for determining whether a test compound down-regulates the expression of CrgE polypeptide, comprising the steps of (a) contacting the test compound with a S. pyogenes bacterium to form a mixture; (b) incubating the mixture to allow the compound and the bacterium to interact; and (c) determining whether expression of the polypeptide is down-regulated.
13 . A process for determining whether a test compound binds to a CrgE or CrgR polypeptide, comprising the steps of (a) contacting the test compound with the polypeptide to form a mixture; (b) incubating the mixture to allow the compound and the polypeptide to interact; and (c) determining whether the compound and polypeptide interact.
14 . A process for determining whether a test compound inhibits the enzymatic activity of a CrgE or CrgR polypeptide, comprising the steps of: (a) contacting the test compound with the polypeptide and a substrate for the enzymatic reaction catalysed by the polypeptide; (b) incubating the mixture to allow the compound, polypeptide and substrate to interact; and (c) determining whether modification of the substrate by the enzymatic activity of the polypeptide is inhibited by the test compound.
15 . A compound identified by the process of any one of claims 12 - 14 .
16 . A method for detecting a bacterium expressing a CrgE or CrgR polypeptide, comprising the steps of: (a) contacting a S. pyogenes bacterium with an antibody specific for CrgR or CrgE; (b) incubating the mixture to allow the antibody and bacterium to interact; and (c) detecting binding of the antibody to the bacterium.
17 . A method for detecting a bacterium expressing a CrgE or CrgR polypeptide, comprising the steps of: (a) contacting a S. pyogenes bacterium with a first antibody specific for CrgR or CrgE; (b) incubating the mixture to allow the first antibody and bacterium to interact; (c) contacting the mixture with a second labelled antibody specific for the first antibody; and (d) detecting binding of the second labelled antibody to the first antibody.
18 . A pharmaceutical composition comprising CrgE polypeptide or a homologue thereof.
19 . A composition according to claim 18 further comprising a pharmaceutically acceptable carrier.
20 . (canceled)
21 . (canceled)
22 . A method of enhancing an immune response in a mammal comprising administering an effective amount of a composition according to claim 18 or claim 19 .