Compositions of influenza hemagglutinin with heterologous epitopes and/or altered maturation cleavage sites and methods of use thereof
Modified forms of hemagglutinin (HA) protein including those with modified immunodominant regions and with modified maturation cleavage sites, and virus and virus-like particles containing them are disclosed.
1. A method of producing a modified influenza HA protein, said method comprising:
(i) culturing a cell in the presence of a culture medium comprising a nucleic acid expression vector encoding a modified HA protein amino acid sequence, wherein the modified HA protein comprises: a) a globular head domain and a stem domain, wherein the globular head domain of said modified HA protein comprises at least one heterologous immunogenic epitope, and (b) a modified maturation cleavage site (MCS) not cleavable by any animal proteases but cleavable by a non-animal protease, under conditions suitable for expression of the modified HA protein; and
(ii) isolating the modified HA protein from the cells and/or the culture medium.
2. The method of claim 1 , wherein at least one immunodominant region in the globular head domain comprises an HA stem epitope recognized by a broadly neutralizing antibody (bnAb) against influenza viruses.
3. The method of claim 1 , wherein the expression vector is a recombinant baculoviral vector, and wherein the cell is an insect cell.
4. The method of claim 1 , wherein an immunogenic epitope heterologous to the globular head domain of the HA protein has been inserted into or has replaced at least one immunodominant region in the globular head domain of said HA protein.
5. The method of claim 4 , wherein the heterologous immunogenic epitope is of a tumor associated antigen or an epitope of a virus other than influenza or an alternate influenza epitope.
6. The method of claim 4 , wherein the heterologous immunogenic epitope is an HA stem epitope that is a conserved region of an HA stem domain and is recognized by a bnAb against influenza viruses.
7. The method of claim 4 , wherein more than one immunodominant region of said HA protein has been modified to contain the same heterologous immunogenic epitope.
8. The method of claim 4 , wherein more than one immunodominant region of said HA protein has been modified to contain distinct heterologous immunogenic epitopes.
9. A composition, comprising the modified influenza HA protein of claim 1 .
10. A method of eliciting an immune response against one or more influenza strains or isolates in a subject, the method comprising administering a therapeutically effective amount of the modified HA protein produced by the method of claim 1 .
11. The method of claim 10 , wherein the eliciting of an immune response comprises the generation of antibodies.
12. The method of claim 11 , wherein the antibodies are specific for the modified influenza HA.
13. The method of claim 12 , wherein the antibodies are broadly neutralizing against one or more isolates of influenza.
14. A method of inhibiting infection in a subject by one or more influenza strains or isolates, the method comprising administering a therapeutically effective amount of the modified HA protein produced by the method of claim 1 .
15. The method of claim 14 , wherein the inhibiting infection comprises the generation of antibodies.
16. The method of claim 15 , wherein the antibodies are specific for the modified influenza HA.
17. The method of claim 16 , wherein the antibodies are broadly neutralizing against one or more isolates of influenza.