Vaccine candidates for human respiratory syncytial virus (RSV) having attenuated phenotypes
Inventors
LENOUEN, Cyril • Buchholz, Ursula J. • Collins, Peter L. • Mueller, Steffen
Assignees
Codagenix Inc • US Department of Health and Human Services
Publication Number
US-10808012-B2
Publication Date
2020-10-20
Expiration Date
2037-09-22
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Reported herein are presumptively de-attenuating mutations that are useful, either individually or in combinations that may include other known mutations, in producing recombinant strains of human respiratory syncytial virus (RSV) exhibiting attenuation phenotypes. Also described herein is a novel RSV construct, Min_L-NPM2-1(N88K)L, which exhibits an attenuated phenotype, is stable and is as immunogenic as wild type RSV. The recombinant RSV strains described here are suitable for use as live-attenuated RSV vaccines. Exemplary vaccine candidates are described. Also provided are polynucleotide sequences capable of encoding the described viruses, as well as methods for producing and using the viruses.
Core Innovation
Reported herein are presumptively de-attenuating mutations useful, either individually or in combination with other known mutations, in producing recombinant strains of human respiratory syncytial virus (RSV) exhibiting attenuation phenotypes in vivo. A novel recombinant RSV construct, Min_L-NPM2-1(N88K)L, exhibits an attenuated phenotype, is stable, and is as immunogenic as wild type RSV. The recombinant RSV strains described are suitable as live-attenuated RSV vaccines. Also provided are polynucleotide sequences encoding these viruses and methods for producing and using the viruses.
The problem being solved is the need for live attenuated RSV strains that efficiently replicate in vitro, are maximally immunogenic, attenuated, and refractory to de-attenuation in vivo. RSV is a significant cause of morbidity and mortality, especially in infants, with no commercially available vaccines. Previous vaccine development was complicated by enhanced disease from inactivated or subunit vaccines. Live-attenuated RSV vaccines are preferable but balancing attenuation with immunogenicity and genetic stability has been challenging, especially with RNA virus genetic instability, difficulty identifying attenuating mutations that do not preclude vaccine manufacture, and lack of animal models permissive for RSV replication.
Claims Coverage
The patent discloses two independent claims covering isolated polynucleotide molecules encoding recombinant RSV variants with attenuated phenotypes and specific mutations or combinations thereof.
Mutation in the L open reading frame (ORF) at position T1166
An isolated polynucleotide molecule encoding a recombinant RSV variant having an attenuated phenotype comprising a RSV genome or antigenome sequence, wherein the RSV genome or antigenome is modified by a mutation in the L ORF at a position corresponding to T1166 of the L protein in SEQ ID NO:11.
Further mutations in M2-1, N, and P ORFs enhancing attenuation or stability
The RSV genome or antigenome is further modified by a mutation selected from: (i) a mutation in the M2-1 ORF at a position corresponding to N88 or A73 of the M2-1 protein (SEQ ID NO:9), (ii) a mutation in the N ORF at a position corresponding to K136 of the N protein (SEQ ID NO:3), (iii) a mutation in the P ORF at a position corresponding to E114 of the P protein (SEQ ID NO:4), and combinations thereof.
Specific amino acid substitutions
The mutation in the L ORF at position T1166 may be T1166I; mutations in M2-1 at N88 may be N88K and at A73 may be A73S; in N at K136 may be K136R; and in P at E114 may be E114V. The genome may comprise at least two or all of these mutations in various combinations.
The independent claims cover isolated polynucleotides encoding recombinant RSV genomes or antigenomes modified by a mutation in the L ORF at position T1166 and optionally additional mutations in the M2-1, N, and P ORFs at specified positions, with specific amino acid substitutions. The claims also encompass vectors, cells, pharmaceutical compositions comprising the encoded RSV variants, methods of vaccination by administering these compositions, and live attenuated RSV vaccines.
Stated Advantages
The Min_L-NPM2-1[N88K]L virus is significantly more attenuated in vivo than the parental Min_L virus while being as immunogenic as wild type RSV.
Min_L-NPM2-1[N88K]L virus exhibits increased replication in Vero cells compared to Min_L, which is beneficial for vaccine manufacture.
Min_L-NPM2-1[N88K]L virus displays genetic stability during temperature stress testing, indicating a stable attenuation phenotype and resistance to de-attenuation.
Documented Applications
Use of the recombinant RSV strains as live attenuated vaccines against human respiratory syncytial virus infection.
Pharmaceutical compositions comprising immunologically effective amounts of the recombinant RSV variants for vaccination purposes.
Methods of vaccinating subjects against RSV by administering the pharmaceutical compositions via injection, aerosol delivery, nasal spray, or nasal droplets.
Interested in licensing this patent?