HCV core and minicore binding molecules
The present disclosure relates to hepatitis C virus (HCV) core and minicore-binding molecules and nucleic acid sequences encoding such molecules. In particular embodiments, the present invention provides HCV core and minicore-binding molecules (e.g., monoclonal antibodies or antibody fragments) with particular light chain and/or heavy chain CDRs (e.g., selected from SEQ ID NOS: 2-4 and 6-8) and methods for using such molecules to detect the presence of HCV core proteins (e.g., mature p21 core protein or minicore proteins) in a sample.
1. A hepatitis C virus (HCV) core protein-binding molecule, comprising:
a) a light chain variable region comprising
i) a first light chain complementarity determining region (CDRL1) consisting of an amino acid sequence selected from the group consisting of SEQ ID NO: 2, and SEQ ID NO: 2 with one or more conservative amino acid changes;
ii) a second light chain CDR (CDRL2) consisting of an amino acid sequence selected from the group consisting of SEQ ID NO:3 and SEQ ID NO:3 with one or more conservative amino acid changes; and
iii) a third light chain CDR (CDRL3) consisting of an amino acid sequence selected from the group consisting of SEQ ID NO:4 and SEQ ID NO:4 with one or more conservative amino acid changes; and
b) a heavy chain variable region, comprising
i) a first heavy chain CDR (CDRH1) consisting of an amino acid sequence selected from the group consisting of SEQ ID NO:6 and SEQ ID NO:6 with one or more conservative amino acid changes;
ii) a second heavy chain CDR (CDRH2) consisting of an amino acid sequence selected from the group consisting of SEQ ID NO:7 and SEQ ID NO:7 with one or more conservative amino acid changes; and
iii) a third heavy chain CDR (CDRH3) consisting of an amino acid sequence selected from the group consisting of SEQ ID NO:8 and SEQ ID NO:8 with one or more conservative amino acid changes.
2. The HCV core protein-binding molecule of claim 1 , wherein said HCV core protein-binding molecule is an antibody or antibody fragment capable of binding HCV p21 core protein and/or HCV 70 or 91 minicore protein.
3. The HCV core protein-binding molecule of claim 1 , wherein said antibody fragment is an Fab or Fv antibody fragment.
4. The HCV core protein-binding molecule of claim 1 , wherein said antibody fragment comprises an antigen binding portion of the Neo4 antibody.
5. The HCV core protein-binding molecule of claim 1 , wherein said light and/or heavy chain variable region comprises a mouse or human framework region.
6. The HCV core protein-binding molecule of claim 1 , wherein said HCV core protein-binding molecule has a higher binding affinity for p21 core or a minicore protein than monoclonal antibody C11-3 (ABT-4).
7. The HCV core protein-binding molecule of claim 1 , wherein said HCV core protein-binding molecule is capable of binding HCV p21 core protein.
8. The HCV core protein-binding molecule of claim 1 , wherein said HCV core protein-binding molecule is capable of binding HCV 70 or 91 minicore protein.
9. A composition comprising the HCV core protein-binding molecule of claim 1 .
10. A nucleic acid comprising:
a) a first nucleic acid sequence encoding a light chain variable region, wherein said light chain variable region comprises
i) a CDRL1 consisting of an amino acid sequence selected from the group consisting of SEQ ID NO: 2 and SEQ ID NO: 2 with one or more conservative amino acid changes;
ii) a CDRL2 consisting of an amino acid sequence selected from the group consisting of SEQ ID NO: 3 and SEQ ID NO: 3 with one or more conservative amino acid changes; and
iii) a CDRL3 consisting of an amino acid sequence selected from the group consisting of SEQ ID NO: 4 and SEQ ID NO: 4 with one or more conservative amino acid changes; and
b) a second nucleic acid sequence encoding a heavy chain variable region, wherein said heavy chain variable region comprises;
i) a CDRH1 consisting of an amino acid sequence selected from the group consisting of SEQ ID NO:6 and SEQ ID NO:6 with one or more conservative amino acid changes;
ii) a CDRH2 consisting of an amino acid sequence selected from the group consisting of SEQ ID NO:7 and SEQ ID NO:7 with one or more conservative amino acid changes; and
iii) a CDRH3 consisting of an amino acid sequence selected from the group consisting of SEQ ID NO:8 and SEQ ID NO:8 with one or more conservative amino acid changes.
11. The nucleic acid of claim 10 , wherein said light chain variable region comprises a mouse or human framework region.
12. The nucleic acid of claim 10 , wherein said heavy chain variable region comprises a mouse or human framework region.
13. An expression vector comprising the nucleic acid of claim 10 .
14. A host cell comprising a nucleic acid of claim 10 .
15. A method of detecting an HCV core protein in a sample comprising:
a) contacting a sample suspected of containing an HCV core protein with a HCV core protein-binding molecule of claim 1 , wherein said HCV core protein binding molecule forms a complex with said HCV core protein if present in said sample; and
b) detecting the presence or absence of said complex in said sample.
16. The method of claim 15 , wherein said HCV core protein binding molecule comprises a detectable label.
17. The method of claim 15 , wherein said HCV core protein comprises mature p21 core protein.
18. The method of claim 15 , wherein said HCV core protein comprises 70 or 91 minicore protein.
19. The method of claim 15 , further comprising contacting said sample with a conjugate molecule capable of binding to said HCV core protein binding molecule, wherein said conjugate molecule comprises a detectable label.
20. The method of claim 19 , wherein said conjugate molecule comprises an anti-mouse antibody or a conjugate peptide.
21. The method of claim 15 , wherein said HCV core protein binding molecule comprises biotin, and said method further comprises contacting said sample with streptavidin coated paramagnetic microparticles.
22. The method of claim 15 , wherein said conjugate peptide comprises at least 5 consecutive amino acids from the amino acid sequence: SPRGSRPSWGPTDPRRRSRNLGKVI (SEQ ID NO: 36).
23. The method of claim 15 , wherein said detecting comprises adding a chemiluminescent solution to said sample.
24. A host cell comprising an expression vector of claim 13 .