RECOMBINANT VIRUS, COMPOSITION COMPRISING THE SAME, AND USES THEREOF
Immunogenic compositions comprising hemagglutinin (HA) variants and/or neuraminidase (NA) variants, which may be contained in an influenza A virus, and uses thereof for eliciting immune responses against influenza A virus.
1 . A method of preparing a recombinant Influenza A virus (IAV) comprising a mutant neuraminidase (NA), the method comprising introducing a substitution by site-directed mutagenesis, wherein the substitution is selected from:
(i) substitution of Asn (N) residues with Ala (A) residues at positions corresponding to residues 44, 72, and 219 of SEQ ID NO: 4;
(ii) substitution of Arg (R) residue with Ala (A) residue at a position corresponding to residue 102 of SEQ ID NO: 4; and
(iii) substitution of Asp (D) residue with Ala (A) residue at a position corresponding to residue 135 of SEQ ID NO: 4.
2 . The method of claim 1 , wherein the recombinant Influenza A virus (IAV) exhibits reduced virulence relative to a wild-type Influenza A virus.
3 . The method of claim 1 , wherein the recombinant Influenza A virus (IAV) elicits a CD8 + T-cell immune response upon administration to a subject.
4 . The method of claim 1 , wherein the mutant neuraminidase (NA) lacks neuraminidase catalytic activity relative to a wild-type neuraminidase of SEQ ID NO: 4.
5 . The method of claim 1 , wherein the substitution comprises substitution of Asn (N) residues with Ala (A) residues at positions corresponding to residues 44, 72, and 219 of SEQ ID NO: 4, wherein the mutant neuraminidase (NA) consists of the amino acid sequence of SEQ ID NO: 11.
6 . The method of claim 1 , wherein the substitution comprises substitution of Arg (R) residue with Ala (A) residue at a position corresponding to residue 102 of SEQ ID NO: 4, wherein the mutant neuraminidase (NA) consists of the amino acid sequence of SEQ ID NO: 12.
7 . The method of claim 1 , wherein the substitution comprises substitution of Asp (D) residue with Ala (A) residue at a position corresponding to residue 135 of SEQ ID NO: 4, wherein the mutant neuraminidase (NA) consists of the amino acid sequence of SEQ ID NO: 13.