Method for producing cell-fushion type morbillivirus mutants
View Patent ↗It was found that a mutation of an amino acid at a specific position in the F protein of a morbillivirus induces a reduction in the cell-fusion ability. By introducing this mutation, a virus having a reduced cell-fusion ability can be produced. Thus, attenuated viruses useful in the preparation of vaccines can be easily produced.
1. A method for reducing the cell-fusion ability of a virus comprising introducing a mutation in vitro to a position corresponding to the 278 th amino acid in a protein of the amino acid sequence set forth in SEQ ID NO: 2;
wherein the virus is of the genus Morbillivirus ; or
the virus comprises an F protein having at least 65% identity to the amino acid sequence set forth in SEQ ID NO: 2;
wherein the method does not include converting the virus to a virus identical to measles virus AIK-C.
2. The method according to claim 1 , wherein the virus is a measles virus.
3. The method according to claim 1 , comprising substituting the amino acid at a position corresponding to the 278 th position with leucine.
4. The virus with a reduced cell-fusion ability obtained by the method according to claim 1 .
5. The virus according to claim 4 , wherein the virus is an attenuated virus.
6. A composition comprising the virus according to claim 4 , and pharmacologically acceptable carrier or media.
7. The method of claim 1 , wherein the virus is a distemper virus or rinderpest virus.
8. The method of claim 1 , wherein the protein encoded by the gene is different than the F protein of measles virus AIK-C strain.
9. The method of claim 1 , further comprising five or less additional substitutions in the protein.
10. The method of claim 1 , further comprising three or less additional substitutions in the protein.
11. The method of claim 1 , further comprising one additional substitution in the protein.
12. The method of claim 1 , wherein the protein is changed only at the position corresponding to the 278 th position.
13. The method of claim 1 , wherein only the F gene is changed.
14. The method of claim 1 , wherein only the F and the P genes are changed.
15. A method of producing a DNA encoding mutant protein having a reduced cell fusion ability, comprising
introducing a mutation in vitro so that the mutant protein encoded by the DNA comprises an amino acid other than phenylalanine at the position corresponding to the 278 th position of a protein of the amino acid sequence of SEQ ID NO: 2; wherein the protein is
a protein derived from the F protein of virus belonging to the genus Morbillivirus , wherein the protein has phenylalanine at the position corresponding to the 278 th position of a protein comprising the amino acid sequence of SEQ ID NO: 2; or
an F protein having at least 65% identity to the amino acid sequence set forth in SEQ ID NO: 2, wherein the protein has phenylalanine at the position corresponding to the 278 th position of a protein comprising the amino acid sequence of SEQ ID NO: 2.
16. The method of claim 15 , wherein the protein encoded by the DNA is not converted to a protein identical to the F protein of measles virus AIK-C strain.
17. The method of claim 15 , further comprising five or less additional substitutions in the protein.
18. The method of claim 15 , further comprising three or less additional substitutions in the protein.
19. The method of claim 15 , further comprising one additional substitution in the protein.
20. The method of claim 15 , wherein the protein is changed only at the position corresponding to the 278 th position.
21. The method of claim 15 , wherein the protein is derived from a measles virus.
22. The method of claim 15 , wherein the protein is derived from a distember virus or a rinderpest virus.
23. The method of claim 15 , wherein the amino acid at the position corresponding to the 278 th position is substituted with leucine.
24. An isolated DNA produced by the method of claim 15 or a replicated DNA thereof, wherein the DNA encodes a protein other than the F protein of measles virus AIK-C strain.
25. An isolated protein encoded by the DNA of claim 24 .
26. A vector having the DNA of claim 24 .
27. The vector of claim 26 , wherein the vector encodes a viral genomic RNA.
28. A proliferated virus of the virus according to claim 4 , having the mutation at the 278 th amino acid in the F protein, and with a reduced cell-fusion ability.