US2020317746A1PendingUtilityA1

Targeted and modular exosome loading system

Assignee: UNIV NORTHWESTERNPriority: Sep 30, 2013Filed: Jan 17, 2020Published: Oct 8, 2020
Est. expirySep 30, 2033(~7.2 yrs left)· nominal 20-yr term from priority
C12N 15/85C07K 2319/06C12N 15/88A61K 47/6901A61K 31/713A61K 9/5068C07K 2319/85C07K 14/705
58
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Claims

Abstract

Disclosed are exosomes that include a packaging protein and a cargo RNA in which the packaging protein binds specifically to the cargo RNA. The packaging protein is a fusion protein that includes an RNA-binding domain and an exosome-targeting domain. The cargo RNA includes an RNA-motif that the RNA-binding domain of the fusion protein binds specifically such that the cargo RNA is packaged in the lumen of the exosomes.

Claims

exact text as granted — not AI-modified
We claim: 
     
         1 . Exosomes comprising a packaging protein and a cargo RNA that binds to the packaging protein. 
     
     
         2 . The exosomes of  claim 1 , wherein the packaging protein is a fusion protein comprising an RNA-binding domain and an exosome-targeting domain, and wherein the cargo RNA comprises an RNA-motif and the RNA-binding domain of the fusion protein binds specifically to the RNA-motif of the cargo RNA. 
     
     
         3 . The exosomes of  claim 2 , wherein the RNA-binding domain is an RNA-binding domain of a bacteriophage, and wherein the RNA-motif is a high affinity binding loop of RNA of the bacteriophage. 
     
     
         4 . The exosomes of  claim 3 , wherein the RNA-binding domain is the RNA-binding domain of MS2 bacteriophage comprising SEQ ID NO:2 or a variant thereof having at least 80% amino acid sequence identity to SEQ ID NO:2, and wherein the RNA-motif is a high affinity binding loop comprising a sequence and structure selected from the group consisting of: 
       
         
           
                 
                 
                 
                 
                 
                 
                 
               
                     
                   U U 
                     
                   C U 
                     
                   U C 
                     
                 
                     
                   A   A 
                     
                   A   A 
                     
                   A   A 
                 
                     
                   N-N 
                     
                   N-N 
                     
                   N-N 
                 
                     
                   N-N 
                     
                   N-N 
                     
                   N-N 
                 
                     
                   A     
                     
                   A     
                     
                   A     
                 
                     
                   N-N 
                     
                   N-N 
                     
                   N-N 
                 
                     
                   N-N 
                     
                   N-N 
                     
                   N-N 
                 
                     
                   N-N 
                     
                   N-N 
                     
                   N-N 
                 
                   SEQ ID NO: 4 
                   N-N 
                   SEQ ID NO: 5, 
                   N-N 
                   , and SEQ ID NO: 6, 
                   N-N 
                 
             
                
                
                
                
                
                
                
                
                
               
            
           
         
         where N—N is any two base-paired RNA nucleotides. 
       
     
     
         5 . The exosomes of  claim 4 , wherein the high affinity binding loop comprises a sequence selected from the group consisting of SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9, or a variant thereof having at least 80% amino acid sequence identity to SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9, respectively. 
     
     
         6 . The exosomes of  claim 3 , wherein the RNA-binding domain is the RNA-binding domain of the N-protein of lambda bacteriophage comprising SEQ ID NO:13 or a variant thereof having at least 80% amino acid sequence identity to SEQ ID NO:13, and wherein the RNA-motif is a high affinity binding loop comprising a sequence and structure selected from the group consisting of: 
       
         
           
                 
                 
               
                   A 
                   A 
                 
                   AG 
                   AA 
                 
                   G A 
                   G A 
                 
                   U-A 
                   U-A 
                 
                   C-G 
                   C-G 
                 
                   C-G 
                   C-G 
                 
                   C-G 
                   C-G 
                 
                 
                 
                 
                 
               
                   SEQ ID NO: 16 
                   G-C 
                   and SEQ ID NO: 17 
                   GC 
                 
             
                
                
                
                
                
                
                
               
            
             
                
               
            
           
         
       
     
     
         7 . The exosomes of  claim 3 , wherein the RNA-binding domain is the RNA-binding domain of the N-protein of P22 bacteriophage comprising SEQ ID NO:14 or a variant thereof having at least 80% amino acid sequence identity to SEQ ID NO:14, and wherein the RNA-motif is a high affinity binding loop comprising a sequence and structure of: 
       
         
           
                 
                 
                 
               
                     
                     
                   C 
                 
                     
                     
                   A A 
                 
                     
                     
                   G   A 
                 
                     
                     
                   U-A 
                 
                     
                     
                   C-G 
                 
                     
                     
                   G-C 
                 
                     
                     
                   C-G 
                 
                     
                   SEQ ID NO; 18 
                    G-C. 
                 
             
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         8 . The exosomes of  claim 3 , wherein the RNA-binding domain is the RNA-binding domain of the N-protein of phi22 bacteriophage comprising SEQ ID NO:15 or a variant thereof having at least 80% amino acid sequence identity to SEQ ID NO:15, and wherein the RNA-motif is a high affinity binding loop comprising a sequence and structure of: 
       
         
           
                 
                 
                 
               
                     
                     
                   A A 
                 
                     
                     
                   U   C 
                 
                     
                     
                   C     C 
                 
                     
                     
                   U-G 
                 
                     
                     
                   C-G 
                 
                     
                     
                   C-G 
                 
                     
                     
                   A-U 
                 
                     
                     
                   C-G 
                 
                     
                     
                   U-A 
                 
                     
                   SEQ ID NO: 20 
                    U-G. 
                 
             
                
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         9 . The exosomes of  claim 2 , wherein the exosome-targeting domain is a domain of a lysosome-associated protein. 
     
     
         10 . The exosomes of  claim 9 , wherein the lysosome-associated protein is a lysosome membrane protein. 
     
     
         11 . The exosomes of  claim 10 , wherein the lysosome membrane protein comprises a luminal N-terminus and a cytoplasmic C-terminus. 
     
     
         12 . The exosomes of  claim 10 , wherein the exosome-targeting domain comprises at its C-terminus a sequence selected from a group consisting of SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:27, SEQ ID NO:31, and SEQ ID NO:34, or a variant thereof having at least 80% amino acid sequence identity to SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:27, SEQ ID NO:31, and SEQ ID NO:34, respectively. 
     
     
         13 . The exosomes of  claim 12 , wherein the exosome-targeting domain comprises at its C-terminus SEQ ID NO:24 or a variant thereof having at least 80% amino acid sequence identity to SEQ ID NO:24. 
     
     
         14 . The exosomes of  claim 13 , wherein the RNA-binding domain is fused to the C-terminus of SEQ ID NO:24 or the variant thereof. 
     
     
         15 . The exosomes of  claim 10 , wherein a ligand that targets the exosomes to target cells is present at the N-terminus of the fusion protein and is expressed on the surface of the exosomes. 
     
     
         16 . The exosomes of  claim 1 , wherein the cargo RNA is a hybrid RNA comprising the RNA-motif and further comprising miRNA, shRNA, mRNA, ncRNA, or a combination of any of these RNAs. 
     
     
         17 . A method for preparing the exosomes of  claim 1 , the method comprising (a) expressing in a eukaryotic cell an mRNA that encodes the fusion protein and (b) transducing into the eukaryotic cell the cargo RNA. 
     
     
         18 . A method for delivering a cargo RNA to a target cell, the method comprising contacting the target cell with the exosomes of  claim 1 . 
     
     
         19 . A kit comprising: (a) a vector for expressing a fusion protein comprising an RNA-binding domain and an exosome-targeting domain, and (b) a vector for expressing a cargo RNA comprising an RNA-motif that binds to the RNA-binding domain of the fusion protein. 
     
     
         20 . The kit of  claim 19 , wherein the vectors are separate vectors.

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