Gene therapy vectors for the expression of preprodynorphin variants for the treatment of epilepsy

A delivery vector comprising a DNA sequence encoding pre-prodynorphin or pre-prodynorphin-variants and

• wherein said delivery vector drives expression of a pre-propeptide in a target cell, and
• wherein said delivery vector comprising said DNA sequence enables the release of dynorphin or dynorphin-variants from the target cell on demand, and
• wherein said pre-propeptide is pre-prodynorphin or a pre-prodynorphin-variant and
• wherein said pre-propeptide comprises a signal peptide, wherein the signal peptide is a N-terminal extension of a nascent polypeptide chain and wherein said signal peptide mediates protein targeting to the lumen of the endoplasmatic reticulum, and,
• wherein said pre-propeptide comprises either (i) a N-terminal pro-peptide fragment on the C-terminal end of said signal peptide and wherein said N-terminal pro-peptide fragment comprises a sorting motif comprising the elements DL and EXyL, in particular a sorting motif consisting of the amino acid sequence DLXxEXyL (SEQ ID No. 36), where x is an integer from 1 to 20, y is an integer from 1 to 10, and each instance of X may independently be any amino acid (for the avoidance of doubt, this means that in the present invention in the first sequence of e.g. 1 to 20 X, each X may individually be any amino acid, and in the second sequence of e.g. 1 to 10 X, each X may individually be any amino acid, particularly as further defined herein), or wherein said pre-propeptide comprises (ii) a N-terminal pro-peptide fragment of a pre-pro-neuropeptide or protein sorted to large dense core vesicles, other than pre-prodynorphin, on the C-terminal end of said signal peptide and wherein said N-terminal pro-peptide fragment comprises a sorting motif of said pre-pro-neuropeptide or protein sorted to large dense core vesicles, and wherein said N-terminal pro-peptide fragment consists of 16 to 90 amino acids, and
• wherein said pre-prodynorphin or pre-prodynorphin-variants comprise at least one of the following sequences selected from the group:
• a. Dyn A that is SEQ ID No. 2 or a variant thereof consisting of the first 13 amino acids from the N-terminal end or a variant thereof consisting of the first 8 amino acids from the N-terminal end
• b. Dyn B that is SEQ ID No. 3
• c. leumorphin that is SEQ ID No. 4
• d. variants of Dyn A, said variants having an amino acid sequence identity of at least 60% within the first 8 amino acids from the N-terminal end of SEQ ID No. 2,
• e. variants of Dyn B, said variants having an amino acid sequence identity of at least 60% within the first 8 amino acids from the N-terminal end of SEQ ID No. 3,
• f. variants of leumorphin, said variants having an amino acid sequence identity of at least 60% within the first 8 amino acids from the N-terminal end of SEQ ID No. 4.