Stabilized soluble pre-fusion RSV F polypeptides
Stable pre-fusion respiratory syncitial virus (RSV) F polypeptides, immunogenic compositions including the polypeptides, and uses thereof for the prevention and/or treatment of RSV infection are described.
1. A recombinant pre-fusion respiratory syncytial virus (RSV) Fusion (F) polypeptide, wherein the polypeptide comprises at least two stabilizing mutations in the F1 and/or F2 domain as compared to the RSV F1 and/or F2 domain in a wild-type RSV F protein, wherein at least one of the stabilizing mutations is a mutation of amino acid residue L at position 203 to I.
2. The pre-fusion RSV F polypeptide according to claim 1 , wherein the polypeptide further comprises a mutation of amino acid residue S at position 215 to P.
3. The pre-fusion RSV F polypeptide according to claim 1 , wherein the polypeptide comprises at least one epitope that is specific to the pre-fusion conformation F protein, wherein the at least one epitope is recognized by a pre-fusion specific monoclonal antibody, comprising a heavy chain CDR1 region of SEQ ID NO: 1, a heavy chain CDR2 region of SEQ ID NO: 2, a heavy chain CDR3 region of SEQ ID NO: 3 and a light chain CDR1 region of SEQ ID NO: 4, a light chain CDR2 region of SEQ ID NO: 5, and a light chain CDR3 region of SEQ ID NO: 6 and/or a pre-fusion specific monoclonal antibody, comprising a heavy chain CDR1 region of SEQ ID NO: 7, a heavy chain CDR2 region of SEQ ID NO: 8, a heavy chain CDR3 region of SEQ ID NO: 9 and a light chain CDR1 region of SEQ ID NO: 10, a light chain CDR2 region of SEQ ID NO: 67, and a light chain CDR3 region of SEQ ID NO: 11.
4. The pre-fusion RSV F polypeptide according to claim 1 , wherein the polypeptide is trimeric.
5. The pre-fusion RSV F polypeptide according to claim 1 , comprising a truncated F1 domain, wherein the polypeptide comprises a heterologous trimerization domain linked to the truncated F1 domain.
6. The pre-fusion RSV F polypeptide according to claim 5 , wherein the heterologous trimerization domain comprises the amino acid sequence GYIPEAPRDGQAYVRKDGEWVLLSTFL (SEQ ID NO: 14).
7. The pre-fusion RSV F polypeptide according to claim 5 , wherein the trimerization domain is linked to the truncated F1 domain at amino acid residue 513 of the RSV F protein.
8. The pre-fusion RSV F polypeptide according to claim 1 , wherein the at least one further mutation is selected from the group consisting of:
(a) a mutation of the amino acid residue S at position 46 to G;
(b) a mutation of the amino acid residue N/T at position 67 to I;
(c) a mutation of the amino acid residue L at position 83 to M:
(d) a mutation of the amino acid residue E at position 92 to D;
(e) a mutation of the amino acid residue G at position 184 to N;
(f) a mutation of the amino acid residue V at position 207 to I:
(g) a mutation of the amino acid residue D at position 486 to N; and
(h) a mutation of the amino acid residue E at position 487 to Q, N or I.
9. The pre-fusion RSV F polypeptide according to claim 1 , wherein the F1 domain and/or the F2 domain are from an RSV A strain.
10. The pre-fusion RSV F polypeptide according to claim 1 , wherein the F1 domain and/or the F2 domain are from an RSV B strain.
11. The pre-fusion RSV F polypeptide according to claim 1 , wherein the polypeptide comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 21, SEQ ID NO: 23 and SEQ ID NO: 24.
12. A composition comprising a pre-fusion RSV F polypeptide according to claim 1 .
13. A method of inducing an immune response against RSV F protein in a subject in need thereof, the method comprising administering to the subject the pre-fusion RSV F polypeptide according to claim 1 .
14. A pharmaceutical composition comprising the pre-fusion RSV F polypeptide according to claim 1 , and a pharmaceutical carrier.