Heterologous UTR sequences for enhanced mRNA expression

1. A messenger RNA (mRNA) comprising an open reading frame (ORF) encoding protein, wherein the ORF is flanked by a heterologous 5′ untranslated region (UTR) and/or a heterologous 3′ UTR, wherein the 5′ UTR and/or the 3′ UTR are derived from a gene selected from the group consisting of Haptoglobin (HP), Haptoglobin-Related Protein (HPR), Complement Component 3 (C3), Alpha-1-antitrypsin (SERPINA1), Alpha-1-antichymotrypsin (SERPINA3), Fibrinogen Alpha Chain (FGA), and Fibrinogen Beta Chain (FGB).

2. The mRNA of claim 1 , wherein the mRNA comprises at least one modified or non-naturally occurring nucleotide.

3. The mRNA of claim 2 , wherein the at least one modified or non-naturally occurring nucleotide comprises at least one backbone modification, sugar modification or base modification.

4. The mRNA of claim 3 , wherein the at least one modified or non-naturally occurring nucleotide comprises at least one base modification.

5. The mRNA of claim 4 , wherein the at least one base modification is selected from the group consisting of 2-amino-6-chloropurine riboside 5′ triphosphate, 2-aminoadenosine 5′ triphosphate, 2-thiocytidine 5′ triphosphate, 2-thiouridine 5′ triphosphate, 4-thiouridine 5′ triphosphate, 5-aminoallylcytidine 5′ triphosphate, 5-aminoallyluridine 5′ triphosphate, 5-bromocytidine 5′ triphosphate, 5-bromouridine 5′ triphosphate, 5-iodocytidine 5′ triphosphate, 5-iodouridine 5′ triphosphate, 5-methylcytidine 5′ triphosphate, 5-methyluridine 5′ triphosphate, 6-azacytidine 5′ triphosphate, 6-azauridine 5′ triphosphate, 6-chloropurine riboside 5′-triphosphate, 7-deazaadenosine 5′ triphosphate, 7-deazaguanosine 5′ triphosphate, 8-azaadenosine 5′ triphosphate, 8-azidoadenosine 5′ triphosphate, benzimidazole riboside 5′ triphosphate, N 1 -methyladenosine 5′ triphosphate, N 1 -methylguanosine 5′ triphosphate, N 6 -methyladenosine 5′ triphosphate, O 6 -methylguanosine 5′ triphosphate, N 1 -methyl-pseudouridine 5′ triphosphate, puromycin 5′-triphosphate, and xanthosine 5′ triphosphate.

6. The mRNA of claim 5 , wherein the at least one modified or non-naturally occurring nucleotide is N 1 -methyl-pseudouridine 5′ triphosphate.

7. The mRNA of claim 1 , wherein the mRNA comprises a heterologous 5′ UTR derived from a gene selected from the group consisting of HP, FGB, HPR, C3, FGA, SERPINA1, and SERPINA3.

8. The mRNA of claim 1 , wherein the 5′ UTR comprises a nucleotide sequence selected from the group consisting of SEQ ID NOS:1-3, 5-7, and 10.

9. The mRNA of claim 1 , wherein the ORF is a therapeutic gene.

10. The mRNA of claim 9 , wherein the therapeutic gene is selected from the group consisting of interferon alpha, TNF related apoptosis-inducing ligand, vascular adhesion protein 1, hepatocyte growth factor, G6PC, ABCB11, ABCB4, ASL1, ASS, Arg1, AGXT, OTC, CBS, PAH, GBE, GALE, HADH, MCCC1, MMA, ADAMTS13, SLC25A15, C2, F2, PROS1, SERPINA1, GALT1, ETFA, GCDH, CTNS, FAH, TAT, HPD, HSD17b4, SLC2A2, GALC, ABCC6, AHSG, PDC-E2, GAA, ATP8B1, MMACHC, GK, PCCA, PCCB, and UGT1A1.

11. The mRNA of claim 1 , wherein the mRNA comprises a heterologous 5′ UTR derived from the HP gene.

12. The mRNA of claim 1 , wherein the mRNA comprises a heterologous 5′ UTR derived from the FGB gene.

13. The mRNA of claim 1 , wherein the mRNA comprises a heterologous 5′ UTR derived from the HPR gene.

14. The mRNA of claim 1 , wherein the mRNA comprises a heterologous 5′ UTR derived from the C3 gene.

15. The mRNA of claim 1 , wherein the mRNA comprises a heterologous 5′ UTR derived from the FGA gene.

16. The mRNA of claim 1 , wherein the mRNA comprises a heterologous 5′ UTR derived from the SERPINA1 gene.

17. The mRNA of claim 1 , wherein the mRNA comprises a heterologous 5′ UTR derived from the SERPINA3 gene.

18. The mRNA of claim 1 , wherein the mRNA comprises a heterologous 5′ UTR comprising the nucleotide sequence set forth in SEQ ID NO:2.