| 摘要 |
<p>#CMT# #/CMT# Use, as a pharmaceutical, of a recombinant novirhabdovirus (NRV) in which the gene (I) encoding the NV protein is inactivated. #CMT# : #/CMT# Independent claims are also included for the following: (1) recombinant NRV in which (I) is inactivated and contains in its genome at least one heterologous gene (II) that encodes a vaccinating antigen (Ag) of an organism pathogenic for fish; (2) cDNA (III) from the genome of the new recombinant NRV; (3) recombinant vector containing (III); and (4) vaccine containing an NRV in which (I) is inactivated. #CMT#ACTIVITY : #/CMT# Virucide. #CMT#MECHANISM OF ACTION : #/CMT# Vaccine. The recombinant virus G-IHN-SHV is a recombinant infectious hematopoietic necrosis virus (NHIV) in which the NV gene has been replaced by the glycoprotein G gene of hemorrhagic septicemia virus (SHV). It was administered to young trout by adding to the water at 10 4>-5X10 4>plaque-forming units/ml, with exposure for 3 hours. One month later, the fish were challenged with wild-type NHIV and SHV, at the same level of infection. Mortality over the following 28 days was only 1.3%. #CMT#USE : #/CMT# The recombinant novirhabdovirus (NRV) is used to prepare vaccines, specifically to prevent NRV infection in salmonids, especially where caused by hemorrhagic septicemia virus or infectious hematopoietic necrosis virus. #CMT#ADVANTAGE : #/CMT# Deletion of the NV destroys pathogenicity and its replacement by the glycoprotein gene induces protective immunity. Viruses without NV can still multiply in cell cultures but not in fish, from which they are very rapidly cleared. Unlike known anti-NRV vaccines, th new vaccines do not have to be injected, but can be added to water, allowing simple treatment of young fish, which are at most risk of infection, without risking spread of virus into the environment. #CMT#BIOTECHNOLOGY : #/CMT# Preferred Virus: The recombinant NRV contains a (II) that encodes a capsid or envelope glycoprotein of a virus pathogenic for fish, particularly where (II) is inserted at the NV gene site. (II) may also be inactivated by mutation but preferably is at least (partly) deleted. Specifically the NV gene in infectious hematopoietic necrosis virus (NHIV) is replaced by the glycoprotein G gene of viral hemorrhagic septicemia virus (SHV), or the NV gene of SHV is replaced by the glycoprotein G gene of NHIV. Also contemplated are multivalent vaccines, e.g. those that express the glycoprotein G gene from two NRV species. Preparation: The recombinant NRV are prepared by the method of , i.e. co-transfection of a host cell that expresses RNA polymerase with cDNA for the viral genome and with DNA encoding the N, P and L viral proteins. #CMT#ADMINISTRATION : #/CMT# Recombinant viral vaccines are added to the water. No doses are suggested. #CMT#EXAMPLE : #/CMT# Plasmid pINHV-delta NV-GSHV was prepared from pINHV ( J. Virology, 74 (2000) 11247) by replacing the NV gene with the G gene of hemorrhagic septicemia virus (SHV). It was used, together with plasmids pT7-N, -P and -L (providing other viral proteins), to infect EPC cells, already infected with recombinant vaccinia virus that expressed T7 RNA polymerase. The cells were incubated for 3-4 days then recombinant virus containing the infectious hematopoietic necrosis virus genome in which the NV gene was replaced by the G gene of SHV was recovered.</p> |
