Gas57 mutant antigens and gas57 antibodies

Abstract

The invention provides mutants of GAS57 (Spy0416) which are unable to cleave IL-8 and similar substrates but which still maintain the ability to induce protection against S. pyogenes . The invention also provides antibodies which specifically bind to GAS57 and which inhibit its ability to cleave IL-8 and similar substrates. The mutants are useful, inter alia, in vaccine compositions to induce protection against S. pyogenes . The antibodies are useful, e.g., as therapeutics for treating S. pyogenes infections.

1 . A purified mutant GAS57 antigen comprising an amino acid alteration at one or more amino acid positions selected from the group consisting of amino acids D151, H279, and S617, wherein the amino acid positions are numbered according to SEQ ID NO:1 and wherein proteolytic activity of the purified mutant GAS57 antigen against interleukin 8 (IL-8) is reduced by at least 50% relative to wild-type GAS57 as detected by SDS-polyacrylamide gel electrophoresis or by an ELISA assay. 
     
     
         2 . The purified mutant GAS57 antigen of  claim 1  which comprises at least one amino acid substitution selected from the group consisting of D151A and S617A. 
     
     
         3 . The purified mutant GAS57 antigen of  claim 2  which comprises SEQ ID NO:2 [D151A], SEQ ID NO:3, or SEQ ID NO:4. 
     
     
         4 . The purified mutant GAS57 antigen of  claim 1  which is a fusion protein comprising a second GAS antigen. 
     
     
         5 . The purified mutant GAS57 antigen of  claim 1  which is coupled to a carrier protein. 
     
     
         6 . The purified mutant GAS57 antigen of  claim 5  wherein the carrier protein is selected from the group consisting of a bacterial toxin, a bacterial toxoid, a  N. meningitidis  outer membrane protein, a heat shock protein, a pertussis protein,  H. influenzae  protein D, a cytokine, a lymphokine, a hormone, a growth factor,  C. difficile  toxin A,  C. difficile  toxin B, and an iron-uptake protein. 
     
     
         7 . A nucleic acid molecule encoding the purified mutant GAS57 antigen of  claim 1 . 
     
     
         8 . The nucleic acid molecule of  claim 7  which encodes an amino acid sequence selected from the group consisting of SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4. 
     
     
         9 . The nucleic acid molecule of  claim 6  which comprises a nucleotide sequence selected from the group consisting of coding sequences shown in SEQ ID NO:6, SEQ ID NO:7, and SEQ ID NO:8. 
     
     
         10 - 12 . (canceled) 
     
     
         13 . A composition comprising:
 (a) an active agent selected from:
 (i) a purified mutant GAS57 antigen comprising an amino acid mutation at one or more amino acid positions selected from the group consisting of amino acids D 151, H279, and 5617, wherein the amino acid positions are numbered according to SEQ ID NO:1 and wherein proteolytic activity of the purified mutant GAS57 antigen against interleukin 8 (IL-8) is reduced by at least 50% relative to wild-type GAS57 as detected by SDS-polyacrylamide gel electrophoresis or by an ELISA assay; and 
 (ii) a nucleic acid molecule which encodes the purified mutant GAS57 antigen; and 
   (b) a pharmaceutically acceptable carrier.   
     
     
         14 . The composition of  claim 13  further comprising an active agent which is useful in a pediatric vaccine. 
     
     
         15 . The composition of  claim 14  wherein the active agent is selected from the group consisting of:
 (a) a polypeptide antigen selected from the group consisting of  N. meningitidis, S. pneumoniae, Bordetella pertussis, Moraxella catarrhalis, Clostridium tetani, Chorinebacterim diphteriae , respiratory syncytial virus, polio virus, measles virus, mumps virus, rubella virus, and rotavirus polypeptide antigens; and 
 (b) a nucleic acid molecule which encodes the polypeptide antigen. 
 
     
     
         16 . The composition of  claim 13  further comprising a second active agent which is useful in a vaccine for elderly or immunocompromised individuals. 
     
     
         17 . The composition of  claim 16  wherein the second active agent is selected from the group consisting of:
 (a) a polypeptide antigen selected from the group consisting of  Enterococcus faecalis, Staphylococcus aureaus, Staphylococcus epidermis, Pseudomonas aeruginosa, Legionella pneumophila, Listeria monocytogenes , influenza virus, and parainfluenza virus polypeptide antigens; and 
 (b) a nucleic acid molecule which encodes the polypeptide antigen. 
 
     
     
         18 . (canceled) 
     
     
         19 . A method of treating or preventing infection by  Streptococcus pyogenes  comprising administering to an individual in need thereof an effective amount of a composition comprising:
 (a) an active agent selected from:
 (i) a purified mutant GAS57 antigen comprising an amino acid mutation at one or more amino acid positions selected from the group consisting of amino acids D151, H279, and 5617, wherein the amino acid positions are numbered according to SEQ ID NO:1 and wherein proteolytic activity of the purified mutant GAS57 antigen against interleukin 8 (IL-8) is reduced by at least 50% relative to wild-type GAS57 as detected by SDS-polyacrylamide gel electrophoresis or by an ELISA assay; and 
 (ii) a nucleic acid molecule which encodes the purified mutant GAS57 antigen; and 
   (b) a pharmaceutically acceptable carrier.   
     
     
         20 - 24 . (canceled)