This invention provides isolated nucleic acids encoding polypeptides comprising amino acid sequences of streptococcal matrix adhesion (Ema) polypeptides. The invention provides nucleic acids encoding Group B streptococcal Ema polypeptides EmaA, EmaB, EmaC, EmaD and EmaE. The present invention provides isolated polypeptides comprising amino acid sequences of Group B streptococcal polypeptides EmaA, EmaB, EmaC, EmaD and EmaE, including analogs, variants, mutants, derivatives and fragments thereof. Ema homologous polypeptides from additional bacterial species, including S. pneumoniae, S. pyogenes, E. faecalis and C. diptheriae are also provided. Antibodies to the Ema polypeptides and immunogenic fragments thereof are also provided. The present invention relates to the identification and prevention of infections by virulent forms of streptococci. This invention provides pharmaceutical compositions, immunogenic compositions, vaccines, and diagnostic and therapeutic methods of use of the isolated polypeptides, antibodies thereto, and nucleic acids. Assays for compounds which modulate the polypeptides of the present invention for use in therapy are also provided.
1. An isolated antibody which specifically binds to streptococcal Extracellular Matrix Adhesion Protein A (EmaA) comprising the amino acid sequence set forth in SEQ ID NO:2 or a polypeptide comprising amino acids 28-245 of SEQ ID NO:2, wherein the specific binding is to an epitope contained within the amino acid sequence set forth in SEQ ID NO:2 or a polypeptide comprising amino acids 28-245 of SEQ ID NO:2.
2. The antibody of claim 1 , wherein said antibody is a monoclonal antibody.
3. An immortal cell line that produces the monoclonal antibody of claim 2 .
4. The antibody of claim 1 labeled with a detectable label.
5. The antibody of claim 4 , wherein the label is selected from the group consisting of an enzyme, a chemical which fluoresces, and a radioactive element.
6. A pharmaceutical composition comprising one or more antibodies which specifically bind to streptococcal Extracellular Matrix Adhesion Protein A (EmaA), and a pharmaceutically acceptable carrier, wherein EmaA comprises the amino acid sequence set forth in SEQ ID NO:2 or a polypeptide comprising amino acids 28-245 of SEQ ID NO:2, and wherein the specific binding is to an epitope contained within the amino acid sequence set forth in SEQ ID NO:2 or a polypeptide comprising amino acids 28-245 of SEQ ID NO:2.
7. The pharmaceutical composition of claim 6 , further comprising at least one antibody to a protein selected from the group of Spb1 and Spb2, Rib, Lmb, C5a-ase and C protein alpha antigen.
8. A method for treating infection with a bacterium expressing streptococcal Extracellular Matrix Adhesion Protein A (EmaA) comprising administering a therapeutically effective dose of the pharmaceutical composition of claim 6 to a subject in need thereof so that the subject's infection is treated.
9. A method for detecting the presence of streptococcal Extracellular Matrix Adhesion Protein A (EmaA) comprising
a. contacting a sample, wherein the presence or activity of an EmaA streptococcal polypeptide is suspected, with the antibody of claim 1 under conditions that allow binding of the EmaA streptococcal polypeptide and antibody; and
b. detecting whether binding has occurred between the EmaA streptococcal polypeptide from the sample and the antibody;
wherein the detection of binding indicates the presence or activity of EmaA streptococcal polypeptide in the sample.