Expression of surrogate light chains
The present invention concerns surrogate light chain (SURROBODY™) constructs comprising surrogate light chain sequences with heterologous signal sequences.
1. An isolated nucleic acid molecule encoding a surrogate light chain (SLC) polypeptide, wherein the native secretory leader sequence of the polypeptide is replaced by a heterologous secretory leader sequence comprising SEQ ID NO:36 at the N-terminus of said SLC polypeptide.
2. The isolated nucleic acid molecule of claim 1 , wherein the SLC polypeptide comprises a VpreB polypeptide sequence directly fused to a λ5 polypeptide sequence.
3. The isolated nucleic acid molecule of claim 2 , wherein the VpreB polypeptide sequence is linked at its carboxy terminus to the amino terminus of the λ5 polypeptide sequence.
4. An isolated nucleic acid molecule encoding a surrogate light chain (SLC) polypeptide comprising a VpreB polypeptide, wherein the native secretory leader sequence of the VpreB polypeptide is replaced by a heterologous secretory leader sequence of SEQ ID NO:36 at the N-terminus of said VpreB polypeptide.
5. The isolated nucleic acid molecule of claim 4 , wherein the SLC polypeptide further comprises a λ5 polypeptide.
6. The isolated nucleic acid molecule of claim 4 , wherein the SLC polypeptide comprises a VpreB polypeptide sequence fused to a λ5 polypeptide sequence.
7. The isolated nucleic acid molecule of claim 6 , wherein the VpreB polypeptide sequence is directly fused to the λ5 polypeptide sequence.
8. The isolated nucleic acid molecule of claim 6 or 7 , wherein fusion of the VpreB polypeptide sequence and λ5 polypeptide sequence takes place at or around the CDR3 analogous regions of said VpreB polypeptide sequence and said λ5 polypeptide sequence, respectively, wherein the VpreB polypeptide sequence is linked at its carboxy terminus to the amino terminus of the λ5 polypeptide sequence.
9. The isolated nucleic acid molecule of claim 6 or 7 , wherein the VpreB polypeptide sequence is linked at its carboxy terminus to the amino terminus of the λ5 polypeptide sequence.
10. The isolated nucleic acid molecule of any one of claims 4 - 7 , wherein the VpreB polypeptide is selected from the group consisting of a VpreB1 sequence, a VpreB2 sequence, a VpreB3 sequence, and fragments thereof.
11. The isolated nucleic acid molecule of claim 10 , wherein the VpreB sequence is selected from the group consisting of a VpreB1 sequence of SEQ ID NO: 1, a VpreB2 sequence of SEQ ID NOS: 2 and 3, a VpreB3 sequence of SEQ ID NO: 4, a VpreB-like sequence of SEQ ID NO:5, VpreB dTail sequence of SEQ ID NO:6 and fragments thereof.
12. The isolated nucleic acid molecule of any one of claims 5 - 7 , wherein the λ5 polypeptide is selected from the group consisting of a λ5-like polypeptide of SEQ ID NO: 7; a λ5 polypeptide of SEQ ID NO: 8, and a λ5 dTail polypeptide of SEQ ID NO:9 and fragments thereof.
13. The isolated nucleic acid molecule of any one of claims 4 - 7 , wherein the SLC polypeptide comprises a VpreB polypeptide of SEQ ID NO: 1.
14. The isolated nucleic acid molecule of any one of claims 5 - 7 , wherein the SLC polypeptide is a λ5 polypeptide of SEQ ID NO: 8.
15. An isolated nucleic acid molecule encoding a surrogate light chain (SLC) fusion polypeptide with a heterologous secretory leader sequence, wherein the nucleic acid molecule encodes a polypeptide comprising SEQ ID NO: 35.
16. A vector comprising the nucleic acid molecule of any one of claims 1 - 7 , and 15 .
17. A recombinant host cell transformed with the nucleic acid molecule of any one of claims 1 - 7 and 15 .
18. A method for the expression of a surrogate light chain (SLC) polypeptide or SLC construct in a recombinant host cell comprising transforming said recombinant host cell with a nucleic acid molecule encoding an SLC polypeptide or SLC construct, wherein the native secretory leader sequence of the polypeptide is replaced by a heterologous secretory leader sequence, wherein the nucleic acid molecule is the nucleic acid molecule of any one of claims 1 - 7 , and 15 .
19. The method of claim 18 wherein said recombinant host cell is a eukaryotic cell.
20. The method of claim 18 wherein said recombinant host cell is a Chinese Hamster Ovary (CHO) cell.
21. The method of claim 18 wherein said recombinant host cell is a human embryonic kidney (HEK) 293 cell.
22. A recombinant host cell transformed with the vector of claim 16 .