Chimeric West Nile/Dengue viruses and methods of use
Inventors
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-10428313-B2
Publication Date
2019-10-01
Expiration Date
2035-06-19
Abstract
Disclosed herein are chimeric flaviviruses including non-coding regions, non-structural proteins, and at least a portion of a C protein from West Nile virus (WNV), and a prM protein and an E protein from Dengue virus (DENV). The DENV may be DEN1 serotype, DEN2 serotype, DEN3 serotype, or DEN4 serotype. Also disclosed herein are compositions and methods for eliciting an immune response in a subject, such as an immune response to one or more DENV serotypes. In particular embodiments, the compositions include one or more inactivated viruses including a WN/DENV chimeric nucleic acid (such as a tetravalent inactivated vaccine including a WN/DEN1 chimera, a WN/DEN2 chimera, a WN/DEN3 chimera, and a WN/DEN4 chimera). The compositions may be administered to a subject to elicit an immune response.
Core Innovation
The invention disclosed is chimeric flaviviruses comprising non-coding regions, non-structural proteins, and at least a portion of a C protein from West Nile virus (WNV), combined with a prM protein and an E protein from Dengue virus (DENV). The DENV components may be from any of the four DENV serotypes: DEN1, DEN2, DEN3, or DEN4. These chimeras can include various junction configurations between the WNV and DENV genomes, particularly concerning the prM signal sequence portion of the C protein, resulting in Type I, II, or III junction chimeras.
The disclosed chimeric viruses grow more rapidly and to higher titers in cell culture than wild-type DENV, overcoming the slower replication and production difficulties of DENV vaccine production. They maintain DENV antigenic structures on their surface, enabling them to be used in immunogenic compositions, including inactivated vaccines that elicit immune responses to one or more DENV serotypes. These chimeras can be combined in multivalent vaccines to produce protective immunity against multiple DENV serotypes.
The problem being addressed is that dengue virus causes serious morbidity and mortality worldwide, and vaccine production is hampered by the different serotypes, antibody-dependent enhancement, and the slow replication of wild-type DENV in cell cultures. No commercially available vaccines exist for all four DENV serotypes. The chimeric WN/DENV viruses, with higher replication rates and improved growth characteristics, provide a solution by enabling efficient production of immunogenic compositions and safer vaccine candidates. Moreover, due to their virulence in specific mouse models, the chimeras can serve as challenge viruses for evaluating candidate DENV vaccines.
Claims Coverage
The patent includes three independent claims covering nucleic acid chimeras combining WNV and DENV genomic elements and immunogenic compositions containing inactivated chimeric viruses. The main inventive features relate to the structural configuration of the chimera's genome, specific amino acid substitutions enhancing properties, and vaccine compositions.
Chimeric nucleic acid with type II junction prM signal sequence
A nucleic acid chimera comprising a first nucleic acid molecule from a West Nile virus genome encoding non-structural proteins and a C protein with an 18 amino acid signal sequence made of a 5′ portion from WNV and 3′ portion from Dengue virus, and a second nucleic acid molecule encoding at least a portion of a prM protein and E protein from Dengue virus, operably linked so that the second nucleic acid is 3′ to the Dengue portion of the prM signal sequence and 5′ to the WNV non-structural proteins and 3′ non-coding region.
Specific amino acid substitutions in the E protein for improved chimera characteristics
The chimera includes an amino acid substitution at a position corresponding to E protein amino acid 347 of DEN1, DEN2, or DEN4 or amino acid 345 of DEN3, involving histidine to leucine, glutamine to leucine, or valine to leucine changes, improving replication or stability properties.
Chimeric nucleic acid with type III junction prM signal sequence
A nucleic acid chimera comprising a first nucleic acid molecule from a West Nile virus genome encoding non-structural proteins and a C protein, and a second nucleic acid molecule encoding at least a portion of a prM protein and E protein from Dengue virus, where the second nucleic acid is 3′ to the WNV C protein and 5′ to WNV non-structural proteins and 3′ non-coding region, and incorporating the same E protein amino acid substitutions as above for improved characteristics.
Chimeric nucleic acid with type I junction prM signal sequence from Dengue virus
A nucleic acid chimera where the C protein includes a prM signal sequence from Dengue virus rather than WNV, and the second nucleic acid encodes prM and E proteins from Dengue virus operably linked 3′ to the prM signal sequence and 5′ to WNV non-structural proteins and 3′ non-coding region.
Immunogenic compositions comprising inactivated chimeric viruses
Compositions including one or more inactivated viruses comprising the described chimeric nucleic acids in a pharmaceutically acceptable carrier, optionally including specified amino acid substitutions, and formulated as monovalent or tetravalent vaccines targeting multiple DENV serotypes.
Methods of eliciting immune responses using the immunogenic compositions
Methods of immunizing subjects by administering the inactivated chimeric virus compositions to elicit immune responses against one or more DENV serotypes, including multivalent immune responses and administration with or without adjuvants.
The claims focus on the structure of chimeric nucleic acids combining WNV and DENV genetic elements, specific amino acid substitutions that improve viral characteristics, vaccine compositions including inactivated chimeric viruses, and methods of immunization using these compositions, thereby covering the invention's core innovative aspects related to chimeric virus development and use.
Stated Advantages
The chimeras replicate faster and to higher titers in cell cultures than wild-type DENV, improving efficiency of vaccine production.
The chimeras enable production of immunogenic compositions, including inactivated vaccines, eliciting protective immune responses against multiple DENV serotypes.
Balanced immunity against all four DENV serotypes can be achieved using inactivated chimeric virus vaccines, minimizing risks of severe dengue disease due to antibody-mediated enhancement.
The chimeric viruses can serve as virulent challenge strains in mouse models, facilitating evaluation of candidate DENV vaccine efficacy.
Use of chimeras in neutralization assays improves speed and specificity compared to wild-type DENV due to faster growth, higher titers, and better-defined plaques.
Documented Applications
Production of immunogenic compositions, including multivalent inactivated vaccines, for eliciting immune responses to one or more DENV serotypes in subjects.
Use of chimeric viruses as challenge strains in mouse models to assess efficacy of candidate dengue vaccines.
Use of the chimeric viruses in diagnostic and neutralization assays to detect DENV-reactive antibodies more rapidly and specifically than wild-type DENVs.
Use of inactivated chimeric viruses as a booster vaccine in combination with live-attenuated DENV vaccines to achieve balanced immunity.
Interested in licensing this patent?