Construct for the delivery of a molecule into the cytoplasm of a cell

1. A construct comprising

(a) a targeting moiety, wherein the targeting moiety is an antibody or an antibody fragment;

(b) a fusogenic moiety consisting of one or more fusogenic sequence(s) derived from dengue virus glycoprotein E comprising the sequence DRGWGNGCGLFGKGGI (SEQ ID NO:1) or a sequence which shows 1 to 4 substitutions, deletions, or insertions in comparison to SEQ ID NO:1; and

(c) a molecule which is to be delivered into the cytoplasm of a cell,

wherein the targeting moiety, the fusogenic moiety consisting of one or more fusogenic sequence(s) and the molecule which is to be delivered into the cytoplasm of a cell are chemically coupled in a covalent linkage, or wherein the construct is a fusion protein.

2. The construct according to claim 1 , wherein the targeting moiety is a F(ab′) 2 , F(ab) 2 , Fab′, a Fv antibody fragment a scFv a Fab, a VH, an scFv-Fc, an sdFv, a diabody, a triabody, a tetrabody, a minibody, a tandem-scFv, a tandem-scFv-Fc, an scFv-Fc-scFv, a Fab-scFv, a Fab 3 , an IgG-scFv, an scFv-IgG, an IgG-V H or a single domain antibody, preferably a sdAb, a V H H fragment from camelids, or a V NAR fragment from cartilaginous fishes.

3. The construct according to claim 1 , wherein the targeting moiety targets an antigen specific for cancer, an antigen specific for infectious diseases or an antigen specific for autoimmune diseases.

4. The construct according to claim 1 , wherein the targeting moiety is a humanized anti-EGFR antibody single chain Fv fragment (scFv).

5. The construct according to claim 1 , wherein the molecule which is to be delivered into the cytoplasm is selected from the group consisting of a therapeutic moiety, a detectable moiety, a nucleic acid molecule, preferably an siRNA, a carrier molecule, preferably a nanoparticle, a liposome and a viral vector.

6. The construct according claim 5 , wherein the therapeutic moiety is selected from the group consisting of a cytotoxic moiety, an antibody, an antibody fragment, a drug, a chemotherapeutic agent, a small molecule, an enzyme, a hormone, an antisense oligonucleotide, siRNA, RNAi, a radionuclide, a boron compound, a photoactive agent, an anti-angiogenic agent and a pro-apoptotic agent.

7. The construct according to claim 6 , wherein the cytotoxic moiety is selected from the group consisting of RNase A family members, ricin, abrin, alpha toxin, saporin, DNase I, Staphylococcal enterotoxin-A, pokeweed antiviral protein, gelonin, diphtheria toxin, Pseudomonas exotoxin, and Pseudomonas endotoxin.

8. The construct according to claim 7 , wherein the RNase A family member is an RNase derived from Rana pipines.

9. The construct according to claim 1 , wherein the fusogenic moiety consists of one or more fusogenic sequence(s) selected from the group consisting of

(SEQ ID NO: 5)

DRGWGNGCGLFGKGSI;

(SEQ ID NO: 6)

DRGWGNGCGLFGKGSL;

(SEQ ID NO: 7)

DRGWGNGCGLFGKGGV;

(SEQ ID NO: 8)

DRGWHNGCGLFGKGSI;

(SEQ ID NO: 9)

DRGWHNGCGFFGKGSI;

(SEQ ID NO: 10)

DRGWGNGCGLFGKGSM;

(SEQ ID NO: 11)

DRGWGNGCGLFGKGSY;

(SEQ ID NO: 12)

DRGWNNGCGLFGKGSL;

(SEQ ID NO: 13)

NRGWNNGCGLFGKGDI;

(SEQ ID NO: 14)

DRGWGNHCGLFGKGSI;

(SEQ ID NO: 15)

DRGWGNNCGLFGKGSI;

(SEQ ID NO: 16)

DRGWGNGCALFGKGSI;

and

(SEQ ID NO: 17)

DRGWGNHCGFFGKGSI.

10. The construct according to claim 1 , wherein the targeting moiety, the fusogenic moiety consisting of one or more fusogenic sequence(s) and the molecule which is to be delivered into the cytoplasm of a cell are chemically coupled in a covalent linkage.

11. The construct according to claim 1 , wherein the construct is a fusion protein.

12. A nucleic acid molecule encoding the fusion protein according claim 11 .

13. A vector comprising the nucleic acid molecule of claim 12 .

14. A host cell comprising the vector of claim 13 .

15. A pharmaceutical composition comprising the construct according to claim 1 and optionally a pharmaceutical acceptable carrier.

16. A kit comprising the fusogenic moiety of claim 1 .

17. A method of delivering a therapeutic moiety, a detectable moiety, a nucleic acid molecule, preferably an siRNA, a carrier molecule, preferably a nanoparticle, a liposome and a viral vector into the cytoplasm of a cell, wherein said method comprises administering to a subject in need thereof a construct comprising the fusogenic moiety of claim 1 .

18. The method according to claim 17 , wherein said fusogenic moiety consists of one or more fusogenic sequence(s) derived from dengue virus glycoprotein E comprising the sequence as shown in SEQ ID NO:1.

19. The method according to claim 18 , wherein said one or more fusogenic sequence(s) is a sequence which shows 1 to 4 substitutions, deletions, or insertions in comparison to SEQ ID NO:1.