Compositions and Methods Related to Protein A (SpA) Variants

Abstract

The present invention concerns methods and compositions for treating or preventing a bacterial infection, particularly infection by a Staphylococcus bacterium. The invention provides methods and compositions for stimulating an immune response against the bacteria. In certain embodiments, the methods and compositions involve a non-toxigenic Protein A (SpA) variant.

1 - 77 . (canceled) 
     
     
         78 . An isolated polypeptide comprising a  Staphylococcus aureus  Protein A (SpA) D variant domain segment comprising (a) at least one amino acid substitution that disrupts Fc binding and (b) at least one amino acid substitution that disrupts VH3 binding and (c) an amino acid sequence that is at least 70% identical to the amino acid sequence of SEQ ID NO: 2, wherein the amino acid substitutions correspond to at least amino acids at position 9, 10, 36 and/or 37 of SEQ ID NO: 2. 
     
     
         79 . The isolated polypeptide of  claim 78 , wherein the SpA D domain segment is at least 90% identical to the amino acid sequence of SEQ ID NO: 2. 
     
     
         80 . The isolated polypeptide of  claim 78 , further comprising one or more variant domain segments having substitutions in the SpA E domain, A domain, B domain and/or C domain. 
     
     
         81 . The isolated polypeptide of  claim 78 , further comprising a non-Protein A segment. 
     
     
         82 . The isolated polypeptide of  claim 78 , further comprising a second antigen segment, wherein the second antigen segment is a staphylococcal antigen segment selected from Emp, EsxA, EsxB, EsaC, Eap, Ebh, EsaB, Coa, vWbp, vWh, Hla, SdrC, SdrD, SdrE, IsdA, IsdB, IsdC, ClfA, ClfB, and/or SasF segment. 
     
     
         83 . The isolated polypeptide of  claim 78 , wherein the substitutions at amino acids corresponding to positions 9 and 10 are with a lysine residue and the substitutions at amino acids corresponding to positions 36 and 37 are with an alanine residue. 
     
     
         84 . A method of making the polypeptide of  claim 78 , comprising isolating the polypeptide from a host cell expressing the polypeptide. 
     
     
         85 . A composition comprising the isolated polypeptide of  claim 78 . 
     
     
         86 . A vaccine comprising the isolated polypeptide of  claim 78  and a pharmaceutically acceptable excipient. 
     
     
         87 . A method of preventing or treating staphylococcal infection comprising the step of administering the vaccine of  claim 86  to a patient in need thereof. 
     
     
         88 . A method for eliciting an immune response against a  staphylococcus  bacterium in a subject comprising providing to the subject an effective amount of the composition of  claim 85 . 
     
     
         89 . The method of  claim 88 , further comprising administering to the subject a composition comprising a second staphylococcal antigen. 
     
     
         90 . The method of  claim 89 , wherein the second staphylococcal antigen is one or more of Emp, EsxA, EsxB, EsaC, Eap, Ebh, EsaB, Coa, vWbp, vWh, Hla, SdrC, SdrD, SdrE, IsdA, IsdB, IsdC, ClfA, ClfB, and SasF. 
     
     
         91 . An isolated polypeptide comprising a  Staphylococcus aureus  Protein A (SpA) D variant domain segment having amino acid substitutions corresponding to amino acids at position 9, 10, 36 and 37 of SEQ ID NO: 2; wherein the substitutions at amino acids corresponding to positions 9 and 10 are with a lysine residue and the substitutions at amino acids corresponding to positions 36 and 37 are with an alanine residue and wherein the amino acid sequence is at least 70% identical to the amino acid sequence of SEQ ID NO: 2; and optionally wherein the peptide further comprises one or more variant domain segments having substitutions in the SpA E domain, A domain, B domain and/or C domain. 
     
     
         92 . The isolated polypeptide of  claim 92 , wherein the amino acid sequence is at least 90% identical to the amino acid sequence of SEQ ID NO: 2 
     
     
         93 . A method of preventing or treating staphylococcal infection comprising the step of administering the isolated polypeptide of  claim 91  to a patient in need thereof. 
     
     
         94 . A method for eliciting an immune response against a  staphylococcus  bacterium in a subject comprising providing to the subject an effective amount of the isolated polypeptide of  claim 91 . 
     
     
         95 . The method of  claim 94 , further comprising administering to the subject a composition comprising a second staphylococcal antigen. 
     
     
         96 . The method of  claim 95 , wherein the second staphylococcal antigen is one or more of Emp, EsxA, EsxB, EsaC, Eap, Ebh, EsaB, Coa, vWbp, vWh, Hla, SdrC, SdrD, SdrE, IsdA, IsdB, IsdC, ClfA, ClfB, and SasF. 
     
     
         97 . A vaccine composition comprising the isolated polypeptide of  claim 91  and a pharmaceutically acceptable excipient.