Compositions and methods related to protein A (SpA) variants
Disclosed are methods and compositions for treating or preventing a Staphylococcus bacterial infection using a non-toxigenic Protein A (SpA) variant.
1. An isolated polypeptide comprising a Staphylococcal Protein A (SpA) variant domain D segment comprising amino acid substitutions at amino acids corresponding to positions 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 80% identical to SEQ ID NO:2.
2. The polypeptide of claim 1 , wherein the amino acid sequence is at least 85% identical to SEQ ID NO: 2.
3. The isolated polypeptide of claim 1 , further comprising one or more immunogenic fragments of SpA E domain, SpA A domain, SpA B domain, or SpA C domain.
4. The isolated polypeptide of claim 1 , further comprising two or more of immunogenic SpA D domain fragments.
5. The isolated polypeptide of claim 1 , further comprising an immunogenic fragment of a second staphylococcal antigen.
6. The isolated polypeptide of claim 5 , wherein the second staphylococcal antigen is selected from the group consisting of Emp, EsxA, EsxB, EsaC, Eap, Ebh, EsaB, Coa, vWbp, vWh, Hla, SdrC, SdrD, SdrE, lsdA, lsdB, lsdC, ClfA, ClfB and SasF.
7. A composition comprising an isolated polypeptide comprising Staphylococcal Protein A (SpA) variant domain D segment comprising amino acid substitutions at amino acids corresponding to positions 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 80% identical to SEQ ID NO: 2, and optionally wherein the polypeptide further comprises one or more immunogenic fragments of SpA E domain, SpA A domain, SpA B domain, or SpA C domain.
8. The composition of claim 7 , further comprising at least one other staphylococcal antigen selected from the group consisting of Emp, EsxA, EsxB, EsaC, Eap, Ebh, EsaB, Coa, vWbp, vWh, Hla, SdrC, SdrD, SdrE, lsdA, lsdB, lsdC, ClfA, ClfB and SasF.
9. The composition of claim 7 , wherein the composition contains less than 1% by weight of staphylococcal bacterial components other than the polypeptide comprising the SpA variant domain D segment.
10. The composition of claim 7 , further comprising a staphylococcal PIA capsular polysaccharide or its oligosaccharide.
11. The composition of claim 7 , further comprising type V or type VIII capsular polysaccharide of S. aureus or its oligosaccharide.
12. The composition of claim 7 , further comprising a staphylococcal capsular polysaccharide conjugated to a protein carrier.
13. The isolated polypeptide of claim 1 , wherein the polypeptide further comprises one or more immunogenic variants of SpA E domain, SpA A domain, SpA B domain, or SpA C domain that have an amino acid sequence that is at least 80% identical to SEQ ID NOS: 3, 4, 6, and 5, respectively, and wherein the one or more domains comprise amino acid substitutions at amino acids corresponding to positions 9, 10, 36 and 37 of SEQ ID NO: 2, wherein the amino acid substitutions corresponding to positions 9 and 10 are with a lysine residue and the amino acid substitutions corresponding to positions 36 and 37 are with an alanine residue.
14. The composition of claim 7 , wherein the composition further comprises immunogenic fragments comprising one or more of SpA E domain, SpA A domain, SpA B domain, or SpA C domain that have an amino acid sequence that is at least 80% identical to SEQ ID NOS: 3, 4, 6, and 5, respectively, and wherein the one or more domains comprise amino acid substitutions at amino acids corresponding to positions 9, 10, 36 and 37 of SEQ ID NO: 2, wherein the amino acid substitutions corresponding to positions 9 and 10 are with a lysine residue and the amino acid substitutions corresponding to positions 36 and 37 are with an alanine residue.