Respiratory syncytial virus having altered NS1 protein function and related materials and methods
Inventors
Peeples, Mark Edward • TENG, Michael Nan-hao • Ramilo, Octavio • MEJIAS, Maria Asuncion • FLANO, Emilio
Assignees
National Institutes of Health NIH • Nationwide Childrens Hospital Inc
Publication Number
US-10947512-B2
Publication Date
2021-03-16
Expiration Date
2036-08-12
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Abstract
Embodiments disclosed herein provide compositions, methods, and uses for respiratory syncytial viruses (RSV) and immunogenic compositions thereof. Certain embodiments provide RSV having a mutated NS1 protein, where the mutation causes the uncoupling of the NS1 protein's replication and type I interferon (IFN) antagonist functions. In some embodiments, this uncoupling can produce virions capable of inducing a strong, long-lasting innate immune response while maintaining its ability to replicate in vitro. Also provided are methods for amplifying RSV in host cells, wherein amplified RSV has mutated NS1 protein in which the protein's replication and IFN antagonistic functions are uncoupled. In certain embodiments, the amplified RSV having mutated NS1 protein is formulated into immunogenic compositions, including vaccines. Other embodiments provide methods for inducing an effective immune response against RSV infection in a subject.
Core Innovation
Embodiments disclosed provide compositions, methods, and uses for respiratory syncytial viruses (RSV) with a mutated nonstructural protein 1 (NS1) that uncouples the NS1 protein's replication function from its type I interferon (IFN) antagonist function. This uncoupling allows production of virions capable of inducing a strong, long-lasting innate immune response while maintaining the ability to replicate in vitro.
The problem being solved is that RSV naturally induces weak, non-lasting immunity, partly due to the NS1 protein antagonizing interferon responses which limits innate immune activation. Existing RSV vaccines either caused severe disease or had poor production yields, particularly RSV lacking NS1 (ΔNS1) which replicates poorly even in IFN-deficient cells. This invention addresses how to produce RSV that induces strong immune activation without losing replication efficacy needed for economical vaccine production.
The disclosed solution includes RSV having mutated NS1 proteins with deletion or substitution mutations, especially within the first 20 amino-terminal amino acids or the last 10 carboxy-terminal amino acids, that reduce or eliminate IFN antagonism but retain replication function. Such mutant RSV replicate substantially better than ΔNS1 RSV and can be formulated into immunogenic compositions including vaccines. Methods for amplifying these RSV in host cells such as Vero cells, which do not produce interferon, and for formulating immunogenic compositions, are also provided. Additionally, methods of inducing an effective immune response in subjects by administering these compositions are disclosed.
Claims Coverage
The patent includes multiple independent claims covering mutant RSV, immunogenic compositions, methods for producing compositions, and methods of inducing immune responses. These claims focus on the RSV with mutated NS1 protein having specific amino acid deletions or substitutions that uncouple replication and IFN antagonism functions.
Mutant RSV with NS1 amino acid deletions in the first 20 amino acids
A mutant respiratory syncytial virus (RSV) comprising a mutated NS1 protein with an amino acid deletion selected from a specified group of deletions within the first 20 amino-terminal amino acids, relative to an RSV NS1 protein having at least 95% sequence identity with SEQ ID NO: 1.
Additional mutation possibilities in NS1
The mutant RSV may further comprise at least one substitution mutation within the first 20 amino-terminal amino acids or within the 10 carboxy-terminal amino acids of the RSV NS1 protein.
Specific deletion mutations in NS1
Mutant RSV where the deletion mutation is specifically selected from Δ6-10; Δ11; and Δ9,12 within the NS1 protein.
Attenuated mutant RSV
The mutant RSV can be attenuated, suitable for use in vaccination or immunogenic compositions.
Immunogenic composition comprising attenuated mutant RSV
An immunogenic composition against RSV comprising the attenuated mutant RSV and a pharmaceutically acceptable excipient.
Method for producing immunogenic compositions
A method comprising providing a host cell culture, inoculating with the mutant RSV, incubating, harvesting RSV, and formulating into an immunogenic composition against RSV.
Optional purification and formulation steps
Methods optionally include purifying the harvested RSV and formulating it with a pharmaceutically acceptable carrier, vehicle, excipient, adjuvant, or combinations thereof.
Immunogenic compositions produced by the described methods
Compositions produced by the above methods, including amplification and formulation steps.
Method for inducing an effective immune response in subjects
Administering an immunologically effective dose of the immunogenic composition comprising mutant RSV to a subject to induce a protective immune response.
Subject types and administration routes
Subjects can be humans, particularly infants or children, and administration may be intranasal, subcutaneous, intramuscular, intradermal, or oral.
Multiple dosing
The method may include administering at least one subsequent immunologically effective dose of the immunogenic composition against RSV.
The claims cover mutant RSV with NS1 protein deletions and substitutions uncoupling replication and IFN antagonism, their use in attenuated live vaccines, methods for producing and formulating immunogenic compositions thereof, and methods for inducing effective immune responses in subjects through administration of these compositions.
Stated Advantages
The mutated NS1 RSV can induce a strong, long-lasting innate immune response while maintaining efficient viral replication in vitro.
The mutant RSV replicate to peak titers substantially higher than RSV lacking NS1 completely (ΔNS1), improving economic viability for vaccine production.
Live attenuated RSV with mutated NS1 do not cause vaccine-associated enhanced RSV disease and stimulate broad systemic and local immunity, including humoral, cellular, and innate responses.
Mutations uncoupling IFN antagonism from replication limit IFN suppression, allowing infected cells to produce interferon and mount an innate immune response.
Documented Applications
The mutant RSV can be formulated into immunogenic compositions such as vaccines against RSV infection.
Methods for producing immunogenic compositions by amplifying mutant RSV in cell culture and formulating into pharmaceutical compositions.
Administration of immunogenic compositions comprising mutant RSV to induce effective immune responses and prevent or reduce RSV infection or recurrent infection in human subjects including infants and children.
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