CHIMERIC PROTEINS FOR TARGETING dsRNA

Abstract

Described herein are recombinant chimeric proteins comprising a double stranded RNA (dsRNA) binding domain and a cancer-cell targeting domain for targeting of dsRNA to cancer cells. Methods of use of the described chimeric proteins are also provided herein.

1 . A recombinant protein comprising a double stranded RNA (dsRNA) binding domain and a target-binding moiety. 
     
     
         2 . The recombinant protein of  claim 1 , wherein said dsRNA binding domain and said target-binding moiety are connected by a spacer peptide. 
     
     
         3 . (canceled) 
     
     
         4 . The recombinant protein of  claim 1 , wherein said dsRNA binding domain comprises one or more double-stranded RNA-binding motif (dsRBM), i.e. an alpha-beta-beta-beta-alpha fold. 
     
     
         5 . The recombinant protein of  claim 4 , wherein said one or more dsRBM is selected from a dsRBM of dsRNA dependent protein kinase (PKR), TRBP, PACT, Staufen, NFAR1, NFARZ, SPNR, RHA or NREBP. 
     
     
         6 . The recombinant protein of  claim 5 , wherein said dsRNA binding domain comprises two dsRBMs of a PKR, optionally connected by a flexible linker. 
     
     
         7 . The recombinant protein of  claim 6 , wherein said dsRNA binding domain is selected from the dsRNA binding domain of human PKR and said two dsRBMs are connected by a flexible linker; or the full length human PKR. 
     
     
         8 . The recombinant protein of  claim 7 , wherein said dsRNA binding domain comprises amino acid residues 1-197 of human PKR. 
     
     
         9 . The recombinant protein any one of  claim 1 , wherein said target-binding moiety comprises (i) a ligand to a cell surface receptor; (ii) an antibody, such as a humanized antibody; a human antibody; a functional fragment of an antibody; a single-domain antibody, such as a Nanobody; a recombinant antibody; and a single chain variable fragment (scFv); (ii) an antibody mimetic, such as an affibody molecule; an affilin; an affimer; an affitin; an alphabody; an anticalin; an avimer; a DARPin; a fynomer; a Kunitz domain peptide; and a monobody; or (iii) an aptamer. 
     
     
         10 . The recombinant protein of  claim 9 , wherein said target-binding moiety binds a tumor-associated antigen. 
     
     
         11 . The recombinant protein of  claim 10 , wherein said tumor-associated antigen is selected from epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), prostate surface membrane antigen (PSMA), fibroblast growth factor receptor (FGFR), colony stimulating factor 1 receptor (CSF-1R), platelet-derived growth factor receptors (PDGFR), insulin-like growth factor 1 receptor (IGF-1R) and MET. 
     
     
         12 . The recombinant protein of  claim 11 , wherein said target-binding moiety is an EGFR ligand, such as an EGF or the peptide GE11 of the sequence YHWYGYTPQNVI; an anti-EGFR antibody, such as an anti-EGFR scFv or a humanized or human anti-EGFR antibody; or an anti-EGFR affibody. 
     
     
         13 . The recombinant protein of  claim 12 , wherein said EGF is human EGF and said EGFR is human EGFR. 
     
     
         14 - 25 . (canceled) 
     
     
         26 . A complex comprising the recombinant protein of  claim 1  and dsRNA. 
     
     
         27 . The complex of  claim 26 , wherein said dsRNA is dsRNA comprising a polyinosinic acid strand and a polycytidylic acid strand (poly IC). 
     
     
         28 - 31 . (canceled) 
     
     
         32 . A nucleic acid molecule comprising a nucleic acid sequence encoding the recombinant protein of  claim 1 . 
     
     
         33 . The nucleic acid molecule of  claim 32 , wherein said sequence is optimized for expression in a bacterial or plant host cell, preferably a plant host cell. 
     
     
         34 . (canceled) 
     
     
         35 . A method for manufacturing a recombinant protein comprising a dsRNA binding domain and a target-binding moiety, comprising expressing the nucleic acid molecule of  claim 32  in a bacterial or plant cell and extracting said recombinant protein from said cells. 
     
     
         36 - 37 . (canceled) 
     
     
         38 . The method of any one of  claim 35 , comprising expressing the nucleic acid molecule in a plant cell, such as a tobacco or carrot cell, either in suspension or in a whole plant. 
     
     
         39 . A method for treatment of cancer characterized by expression of a tumor-associated antigen, said method comprising systemically administering to a patient in need the complex of  claim 26 . 
     
     
         40 - 63 . (canceled)