Infectious Hematopoietic Necrosis Virus Glycoprotein Research Articles

Characterization of the infectious hematopoietic necrosis virus glycoprotein using neutralizing monoclonal antibodies

Characterization of the infectious hematopoietic necrosis virus glycoprotein using neutralizing monoclonal antibodies

Bacterially expressed nucleoprotein of infectious hematopoietic necrosis virus augments protective immunity induced by the glycoprotein vaccine in fish

The ribonucleoprotein gene of infectious hematopoietic necrosis virus (IHNV) has been expressed in Escherichia coli as a trpE fusion protein. This viral protein does not induce protective immunity to lethal IHNV infection in fish, and virus-neutralizing antibodies do not react with this viral protein. However, when it was administered with a bacterial lysate containing a region of the IHNV glycoprotein, there was enhanced resistance in immunized fish to lethal virus infection.

Epitope mapping and characterization of the infectious hematopoietic necrosis virus glycoprotein, using fusion proteins synthesized in Escherichia coli

A characterization of the antigenic determinants (epitopes) of the glycoprotein (G) of infectious hematopoietic necrosis virus was made by expressing different regions of the G gene in Escherichia coli. A cDNA copy of the G gene was divided into four fragments by TaqI digestion, and the fragments were subcloned into pATH vectors, placing the expression of each G gene fragment under control of the trpE promoter. The resulting plasmids, pXL2, pXL3, and pXL7, encoded trpE-G fusion proteins subsequently detected with anti-infectious hematopoietic necrosis virus sera by Western immunoblots. A comparison of reactivities of the fusion proteins encoded by these plasmids was made by Western immunoblot and radioimmunoassay with a number of anti-G specific monoclonal antibodies (MAbs). The nonneutralizing MAb 136J reacted with the trpE-G fusion protein encoded by pXL3 and fusion proteins encoded by plasmids p52G and p618G, which were described in previous studies (R. D. Gilmore, Jr., H. M. Engelking, D. S. Manning, and J. C. Leong. Bio/Technology 6:295-300, 1988). Another nonneutralizing MAb, 2F, bound to the pXL3 fusion protein, and the neutralizing MAb RB/B5 recognized the pXL7 fusion protein. All fusion proteins were tested as vaccines in rainbow trout fry. Although significant protection was induced by all fusion proteins, the pXL3 fusion protein was most effective as a vaccine.

Expression in Escherichia Coli of an Epitope of the Glycoprotein of Infectious Hematopoietic Necrosis Virus Protects Against Viral Challenge

Plasmid vectors were constructed that expressed an antigenic determinant of the glycoprotein gene of infectious hematopoietic necrosis virus (IHNV) as a fusion protein with the trpE protein of Escherichia coli. Insertion of Sau3AI fragments from the IHNV glycoprotein gene into trpE expression plasmids led to a fusion protein containing a hydrophilic segment of 104 amino acids from the middle portion of the viral glycoprotein. Although this region of the glycoprotein contains three N–linked glycosylation sites and is probably glycosylated in the virus, it is not glycosylated in bacteria. Nonetheless, immunization trials in fish with the crude bacterial lysate containing the fusion protein showed that the trpE–glycoprotein fusion protein produced in bacteria induced protective immunity.