DNA CONSTRUCTS AND HOST CELLS FOR EXPRESSING RECOMBINANT PROTEIN
A DNA construct for expressing a recombinant protein, wherein the DNA construct comprises: —at least one of the nucleotide sequences of SEQ ID No 20 and 21, wherein a nucleotide sequence of SEQ ID 20 and 21 is a TIR sequence; and —a nucleotide sequence which encodes a signal peptide; and wherein a nucleotide sequence of SEQ ID No 20 and 21 comprises at least the first 9 nucleotides of said signal peptide encoding sequence.
1 . A DNA construct for expressing a recombinant protein, wherein the DNA construct comprises:
at least one of the nucleotide sequences of SEQ ID No 20 and 21, wherein a nucleotide sequence of SEQ ID 20 and 21 is a TIR sequence; and
a nucleotide sequence which encodes a signal peptide; and
wherein a nucleotide sequence of SEQ ID No 20 and 21 comprises at least the first 9 nucleotides of said signal peptide encoding sequence.
2 . The DNA construct according to claim 1 , wherein the TIR sequence transcribes into an RNA motif that functions as the protein translation initiation site in an mRNA transcript.
3 . The DNA construct according to claim 1 or 2 , wherein the nucleotide sequence which encodes a signal peptide comprises a nucleotide sequence of SEQ ID No 18 when DNA construct comprises a TIR of nucleotide sequence of SEQ ID No 20.
4 . The DNA construct according to any one of claims 1-3 , wherein the nucleotide sequence which encodes a signal peptide comprises a nucleotide sequence of SEQ ID No 19 when the DNA construct comprises a TIR of nucleotide sequence of SEQ ID No 21.
5 . The DNA construct according to any one of claims 1-4 , wherein the DNA construct comprises nucleotide sequences of SEQ ID No 20 and SEQ ID No 21, wherein the DNA construct comprises two nucleotide sequences which encode signal peptides, wherein the first nucleotide sequence which encodes a signal peptide comprises a nucleotide sequence of SEQ ID No 18, wherein the second nucleotide sequence which encodes a signal peptide comprises a nucleotide sequence of SEQ ID No 19, wherein the nucleotide sequence of SEQ ID No 20 comprises at least the first 9 nucleotides of the nucleotide sequence of SEQ ID No 18, and wherein the nucleotide sequence of SEQ ID No 21 comprises at least the first 9 nucleotides of the nucleotide sequence of SEQ ID No 19.
6 . The DNA construct according to any one of claims 1-5 , wherein the DNA construct comprises a nucleotide sequence which encodes said recombinant protein, wherein said recombinant protein is preferably an antibody, wherein said recombinant protein is more preferably a monoclonal antibody, a polyclonal antibody, a chimeric antibody or a fragment of any of said antibodies, wherein said recombinant protein is most preferably certolizumab or certolizumab biosimilar.
7 . The DNA construct according to any one of claims 1-6 , wherein the nucleotide sequence which encodes a signal peptide is operably linked to the nucleotide sequence which encodes the recombinant protein.
8 . The DNA construct according to any one of claims 1-7 , wherein the nucleotide sequence which encodes said recombinant protein comprises:
a first nucleic acid sequence which encodes a light chain of an antibody; and
a second nucleic acid sequence which encodes a heavy chain of an antibody.
9 . The DNA construct according to claim 8 , wherein the nucleotide sequence which encodes a signal peptide is operably linked to:
the first nucleotide sequence which encodes the light chain of an antibody; and/or
the second nucleotide sequence which encodes the heavy chain of an antibody.
10 . The DNA construct according to any one of claims 1-9 , wherein the DNA construct comprises a Shine-Dalgarno sequence, preferably said Shine-Dalgarno sequence is located upstream from the ATG start codon of the nucleotide sequence which encodes a signal peptide, more preferably said Shine-Dalgarno sequence is located upstream from the ATG start codon of the nucleotide sequence which encodes a signal peptide which is operably linked to the light chain of an antibody.
11 . The DNA construct according to any one of claims 8-10 , wherein the first nucleotide sequence which encodes the light chain of an antibody encodes an amino acid sequence of SEQ ID No 3.
12 . The DNA construct according to any one of claims 8-11 , wherein the second nucleotide sequence which encodes the heavy chain of an antibody encodes an amino acid sequence of SEQ ID No 4.
13 . The DNA construct according to any one of claims 8-12 , wherein the first and second nucleotide sequences which encode for the light and heavy chains of an antibody, respectively, encode amino acid sequences of SEQ ID No 3 and SEQ ID No 4, respectively.
14 . The DNA construct according to any one of claims 8-13 , wherein the first nucleotide sequence which encodes the light chain of an antibody comprises a nucleotide sequence of SEQ ID No 5.
15 . The DNA construct according to any one of claims 8-14 , wherein the second nucleotide sequence which encodes for the heavy chain of an antibody comprises a nucleotide sequence of SEQ ID No 6.
16 . The DNA construct according to any one of claims 8-15 , wherein the first and second nucleotide sequences which encode the light and heavy chains of an antibody, respectively, comprise nucleotide sequences of SEQ ID No 5 and SEQ ID No 6, respectively.
17 . An expression vector comprising the DNA construct according to any one of claims 1-16 .
18 . A host cell comprising the DNA construct according to any one of claims 1-16 or comprising an expression vector according to claim 17 , wherein said host cell is a bacterial cell, more preferably Escherichia coli ( E. coli ), most preferably E. coli comprising a chromosome which comprises a mutation or modification which disables rhamnose metabolism.
19 . The host cell according to claim 18 , wherein said host cell comprises either (i) a chromosome which comprises a mutation in the nucleotide sequence of the rhaB gene which renders RhaB inactive, or (ii) a chromosome in which the nucleotide sequence encoding RhaB is deleted.
20 . The host cell according to claim 18 or 19 , wherein said host cell is an E. coli W3110, preferably comprising a chromosome which comprises a frame shift-mutation in the nucleotide sequence encoding RhaB.
21 . The host cell according to any one of the claims 18-20 , wherein said host cell comprises a chromosome comprising:
a. a frame shift-mutation in the nucleotide sequence encoding RhaB;
b. a degP deletion;
c. a prc deletion; and
d. a sprW148R mutation.
22 . The host cell according to any one of claims 18-21 , wherein said host cell is E. coli W3110 rhaBfs ΔDegP Δprc sprW148R.
23 . An RNA expressed by the DNA construct according to any one of claims 1-16 .
24 . A method of expressing a recombinant protein comprising the use of the host cell according to any one of claims 18-22 .
25 . The method according to claim 24 , further comprising the step of recovering the recombinant protein from the host cell; optionally further comprising one or more steps of purifying the recovered recombinant protein, preferably by one or more chromatography steps.
26 . A recombinant protein obtainable by a method according to claim 24 or 25 .
27 .- 100 . (canceled)