Nucleic acids encoding modified Ebola virus glycoproteins with diminished cytotoxicity while retaining native antigenic structures
Inventors
Sullivan, Nancy • Chakrabarti, Bimal • Yang, Zhi-Yong • Pau, Maria Grazia • Goudsmit, Jaap • Nabel, Gary
Assignees
US Department of Health and Human Services
Publication Number
US-9012618-B2
Publication Date
2015-04-21
Expiration Date
2025-09-27
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Abstract
The invention is related to a nucleic acid molecule comprising a polynucleotide encoding a modified filovirus glycoprotein (GP) having at least one amino acid change located in a relatively conserved region of said GP that decreases in vitro cytotoxicity and retains immunogenicity when compared to in vitro cytotoxicity and immunogenicity of a wild type filovirus GP, and related modified filovirus GPs, plasmid DNAs, recombinant viruses, adenoviruses, pharmaceutical compositions, vaccine compositions, antibodies that are specifically reactive with the modified filovirus GPs, and related methods of making and using the same.
Core Innovation
The invention relates to nucleic acid molecules encoding modified filovirus glycoproteins (GP) that have at least one amino acid change in a relatively conserved region of the GP. This modification decreases in vitro cytotoxicity while retaining immunogenicity compared to the wild type filovirus GP. The invention includes the modified GPs, plasmid DNAs, recombinant viruses, adenoviruses, pharmaceutical and vaccine compositions comprising the nucleic acids or proteins, antibodies reactive with the modified GPs, and methods for making and using these components.
The problem addressed is that Ebola virus GP causes cytopathic effects in cultured cells, such as cell rounding and detachment, which disrupts inflammatory cell function and vasculature integrity, contributing to Ebola virus pathogenesis. While GP is a prime target for vaccine development, its cytotoxicity poses challenges. The invention seeks to provide forms of GP that reduce cytotoxicity while maintaining immunogenicity to enable effective and safer vaccine development.
The invention demonstrates that modifying amino acid residues at specific positions, notably positions 71 or 102 in Ebola Zaire GP or corresponding positions in other filovirus strains, results in decreased cytotoxicity without loss of immunogenic properties. For example, substitution mutations E71D or G102A reduce in vitro cytotoxicity while retaining immunogenicity. The modified GP retains native antigenic structures, enabling protective immunity, as shown by immunization experiments in nonhuman primates using recombinant adenovirus vectors encoding these modified GPs.
Claims Coverage
The patent contains one independent claim defining nucleic acid molecules encoding modified filovirus glycoproteins with specific amino acid changes and related compositions and vectors.
Nucleic acid encoding modified filovirus glycoprotein with specific amino acid changes
A nucleic acid molecule comprising a polynucleotide encoding a modified filovirus GP having at least one amino acid change located at amino acid position 71 or 102 in Ebola Zaire GP or corresponding positions in other filovirus strains, wherein the amino acid change decreases in vitro cytotoxicity and retains immunogenicity compared to filovirus GP without the change.
Specific amino acid substitutions at positions 71 and 102
The amino acid change is specifically E71D or G102A in Ebola Zaire GP or corresponding positions in other filovirus strains.
Encoding by defined nucleotide sequences
The modified filovirus GP is encoded by inserts of nucleotide sequences identified as SEQ ID NO:1, 2, 3, 4, 6, 7, or 8.
Inclusion in plasmid DNA, recombinant virus, and adenovirus vectors
The nucleic acid molecule encoding the modified GP is incorporated in plasmid DNA, recombinant viruses, and adenoviruses for expression.
The independent claim covers nucleic acid molecules encoding filovirus glycoproteins with amino acid substitutions at position 71 or 102 that reduce cytotoxicity but retain immunogenicity, sequence-defined embodiments, and their incorporation into plasmids and viral vectors.
Stated Advantages
The modified filovirus glycoproteins have decreased in vitro cytotoxicity compared to wild type GP.
They retain immunogenicity, enabling effective immune responses and protective immunity.
Vaccines containing these modified GPs offer protection against lethal Ebola virus challenge in nonhuman primates.
The use of recombinant adenoviral vectors expressing modified GPs allows for effective vaccination at lower doses.
Removal of cytopathicity by specific mutations eliminates potential safety issues related to GP cytotoxicity.
Elimination of the need for nucleoprotein (NP) in vaccines simplifies vaccine composition without diminishing protection.
Documented Applications
Use of recombinant adenovirus vectors expressing modified filovirus glycoproteins as vaccines to induce protective immunity against Ebola virus infection.
Administration of vaccine compositions containing nucleic acids or proteins encoding modified filovirus GPs for prophylactic immunization in nonhuman primates and potentially humans.
Methods of inducing or boosting immune responses to Ebola or filovirus antigens using recombinant adenoviruses encoding modified GPs, optionally in prime-boost immunization regimens.
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