Dipeptide-repeat proteins as therapeutic target in neurodegenerative diseases with hexanucleotide repeat expansion
The present invention relates to a method of detecting a disease characterized by an expansion of genomic hexanucleotide repeats as well as polypeptides of said hexanucleotide repeats, ligands specifically binding to the polypeptides, and to methods of identifying an inhibitor preventing the expression and/or aggregation of said polypeptide.
1. An antibody or antigen-binding fragment thereof specifically binding to a polypeptide consisting of (Gly-Ala) m dipeptide repeats, wherein m is an integer of 10 or more, at least three contiguous amino acids of the amino acid sequences according to SEQ ID NO: 3 at its C-terminus, and/or at least three contiguous amino acids of the amino acid sequences according to SEQ ID NO: 14 at its N-terminus,
wherein the antibody or antigen-binding fragment thereof comprises:
(i) a heavy chain CDR3 sequence comprising
(SEQ ID NO: 50)
GDX 1 X 2 NSHFX 3 Y,
wherein:
X 1 is F or Y;
X 2 is T or S; and
X 3 is A or T;
(ii) a light chain CDR3 sequence comprising SEQ ID NO: 53;
(iii) a heavy chain CDR2 sequence comprising
(SEQ ID NO: 51)
EX 4 LPGSGX 5 TK,
wherein:
X 4 is I or N; and
X 5 is S or T;
(iv) a heavy chain CDR1 sequence comprising
(SEQ ID NO: 52)
GYX 8 FX 9 GYWIE,
wherein:
X 8 is T or K; and
X 9 is T or I;
(v) a light chain CDR2 comprising SEQ ID NO: 54; and
(vi) a light chain CDR1 comprising SEQ ID NO: 55.
2. The antibody or antigen-binding fragment thereof according to claim 1 , wherein the heavy chain CDR2 comprises
(SEQ ID NO: 56)
EX 4 LPGSGX 5 TKYNEX 6 FX 7 G,
wherein:
X 4 is I or N;
X 5 is S or T;
X 6 is N or K; and
X 7 is R or K.
3. The antibody or antigen-binding fragment thereof according to claim 1 , wherein the antibody or antibody binding fragment thereof specifically binds to (Gly-Ala) a , with a K D of 1×10 −7 mol.
4. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof according to claim 1 .
5. A method of treating a disease characterized by an expansion of genomic hexanucleotide repeats by administering an antibody or antigen-binding fragment thereof according to claim 1 to a subject in need of treatment of said disease, wherein the disease characterized by an expansion of hexanucleotide repeats is selected from amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), frontotemporal lobar degeneration (FTLD), amyotrophic lateral sclerosis-frontotemporal dementia (ALS-FTD) and spinocerebellar ataxia (SCA36).