Expression of Recombinant Envelope Protein of Japanese Encephalitis Virus YL Strain in Escherichia coli Possesses Hemagglutination Activity

Abstract

The nucleotide sequence of glycoprotein E of YL vaccine strain was cloned, sequenced and expressed in E. coli. Phylogenetic analysis of envelope (E) amino acid sequences of 18 JEVs in GenBank showed that the vaccine strain YL closer to the virulent strain HVI which is a Taiwanese isolate. We found only two amino acid mutations (K-138 and G-389) of E protein might lead viral attenuation in YL. In this study, we used pRSET vector system to construct three recombinant plasmids (pRSET/F1R1, pRSET/F2R2 and pRSET/F1R2), which encoded and expressed different or overlapping amino acid region of E protein. The antigenicity and hemagglutination activity of these recombinant proteins were examined by western blotting and hemagglutination test, respectively. Our results demonstrated that the recombinant protein of pRSET/F1R2 possesses predominant antigenicity and hemagglutination activity.

Programmed Cell Death Induced by Japanese Encephalitis Virus YL Vaccine Strain or Its Recombinant Envelope Protein in Varied Cultured Cells

“…The E-glycoprotein of JEV plays a crucial role in viral pathogenesis by determining the cellular susceptibility and organ tropism of the virus [2,12,14] and it was reported that a single amino acid change of E (138) to K (138) on viral envelope protein would cause a loss of viral neuroinvasiveness and change its organ tropism, of which the main target organ was the liver [8,12] . In our previous study, we compared E-glycoprotein sequences of JEV-YL with other virulent JEVs, revealing two amino acid mutations in the E protein of JEV-YL; one is K (138) and the other is G (389) [18,19] and as a result of these mutations there may be a tropism change from neural cells to liver cells. Therefore, this strain was used as a live-attenuated vaccine.…”

“…As to JEV, the role of E protein for the induction of apoptosis has not been clearly identifi ed. Our previous study had completely sequenced the cDNA of the JEV-YL strain, which has been used widely as live vaccine for the control of animal Japanese encephalitis in Taiwan [18,19] . The amino acid sequence of E protein in JEV-YL has some signifi cant differences, such K (138) and RGG (387)(388)(389) , and may impair in the viral attachment to the cell surface.…”

Recombinant core proteins of Japanese encephalitis virus as activators of the innate immune response

“…The genome of JEV is a single-stranded positive-sense RNA of approximately 11 kb and contains a single open reading frame with the potential to encode a large polyprotein. The JEV polyprotein is cleaved by both host and viral proteases to yield at least 10 distinct products in the order of three structural proteins (core, M, and E), and seven nonstructural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5) [5,6]. The envelope glycoprotein (E), with the presence of a hypervariable region, appears to play a major role in inducing protective immunity and determining viral pathogenicity by defining cellular tropism and triggering apoptosis in infected cells [6][7][8].…”

“…The JEV polyprotein is cleaved by both host and viral proteases to yield at least 10 distinct products in the order of three structural proteins (core, M, and E), and seven nonstructural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5) [5,6]. The envelope glycoprotein (E), with the presence of a hypervariable region, appears to play a major role in inducing protective immunity and determining viral pathogenicity by defining cellular tropism and triggering apoptosis in infected cells [6][7][8]. By contrast, the wellconserved core is a small protein (14 kDa) and possesses multiple functions involved in the formation of the viral nucleocapsid as well as affliction of viral RNA replication [9].…”

N-glycosylation of the premembrane protein of Japanese encephalitis virus is critical for folding of the envelope protein and assembly of virus-like particles

“…JEV has three structural proteins, i.e., capsid, membrane or premembrane (prM), and envelope (E) protein (Chambers et al, 1990). E protein is the main structural protein on the flavivirus surface and plays a major role in viral binding, entry, tissue tropism, neurovirulence, neuroinvasiveness, and immune stimulation (Allison et al, 1995;Alka et al, 2007;Chen et al, 2004;Kroeger and McMinn, 2002;Liu et al, 2004;Ni and Barrett, 1998). prM protein interacts with E protein to form prM-E heterodimer, which is important for flavivirus maturation (Heinz and Allison, 2000;Mackenzie and Westaway, 2001).…”