Mutation analysis of the cross-reactive epitopes of Japanese encephalitis virus envelope glycoprotein

Abstract

Group and serocomplex cross-reactive epitopes have been identified in the envelope (E) protein of several flaviviruses and have proven critical in vaccine and diagnostic antigen development. Here, we performed site-directed mutagenesis across the E gene of a recombinant expression plasmid that encodes the Japanese encephalitis virus (JEV) premembrane (prM) and E proteins and produces JEV virus-like particles (VLPs). Mutations were introduced at I135 and E138 in domain I; W101, G104, G106 and L107 in domain II; and T305, E306, K312, A315, S329, S331, G332 and D389 in domain III. None of the mutant JEV VLPs demonstrated reduced activity to the five JEV type-specific mAbs tested. Substitutions at W101, especially W101G, reduced reactivity dramatically with all of the flavivirus group cross-reactive mAbs. The group and JEV serocomplex cross-reactive mAbs examined recognized five and six different overlapping epitopes, respectively. Among five group cross-reactive epitopes, amino acids located in domains I, II and III were involved in one, five and three epitopes, respectively. Recognition by six JEV serocomplex cross-reactive mAbs was reduced by amino acid substitutions in domains II and III. These results suggest that amino acid residues located in the fusion loop of E domain II are the most critical for recognition by group cross-reactive mAbs, followed by residues of domains III and I. The amino acid residues of both domains II and III of the E protein were shown to be important in the binding of JEV serocomplex cross-reactive mAbs.

Sculpting humoral immunity through dengue vaccination to enhance protective immunity

“…or of the different forms of virus (mature, immature, or partially mature) being delivered. Nevertheless, VLPs produced by our flavivirus and DENV plasmids in tissue culture do contain prM and vaccination with these plasmids can produce antibody recognizing prM (Chang et al, 2003; Chiou et al, 2012). CRR substitutions introduced into these plasmids do not alter the prM processing or change the relative ratios of VLP prM and E or their induced antibody populations in comparison to WT (Chiou et al, 2012).…”

“…Nevertheless, VLPs produced by our flavivirus and DENV plasmids in tissue culture do contain prM and vaccination with these plasmids can produce antibody recognizing prM (Chang et al, 2003; Chiou et al, 2012). CRR substitutions introduced into these plasmids do not alter the prM processing or change the relative ratios of VLP prM and E or their induced antibody populations in comparison to WT (Chiou et al, 2012). Thus, prM antibodies may be of concern in human vaccination and they could explain the residual enhancement observed in CRR vaccinated AG129 mice (Henchal et al, 1985; Roehrig et al, 1998), but they are unlikely to account for the differences in pathology and mortality between pVD1-CRR and -WT immunized mice in this study.…”

Formalin Inactivation of Japanese Encephalitis Virus Vaccine Alters the Antigenicity and Immunogenicity of a Neutralization Epitope in Envelope Protein Domain III

“…Most of the antibodies elicited by JEV infection or immunization are conformation-dependent and, for the most part, recognize the viral E protein and are able to help prevent virus infection [15,53]. Formalin inactivation of several human vaccines has been shown to result in antigenic alteration to the viral particles, which can be measured by the binding activity of specific MAbs [38,40], but the effect of formalin inactivation on commercially available JEV vaccines has not been evaluated.…”

“…Formalin inactivation of several human vaccines has been shown to result in antigenic alteration to the viral particles, which can be measured by the binding activity of specific MAbs [38,40], but the effect of formalin inactivation on commercially available JEV vaccines has not been evaluated. Previously, an established Ag-ELISA protocol was successfully used to determine the antigenic structure of JEV using a panel of anti-E protein MAbs [49,53].…”

Prediction and validation of potent peptides against herpes simplex virus type 1 via immunoinformatic and systems biology approach

“…The antigenic drifts of an antigen permit it to calmly escape the human memory cells response. Similarly, allergenicity in vaccine development is also a calling obstacle (Chiou, Fan, Crill, Chang, & Chang, ). Because most of the vaccines, instead of provoking immunity against an antigen, they cause allergic reaction by the initiation of helper T and type 2 cells along with immunoglobulin E. Thus, we confirmed both the antigenic and allergenic nature of the proposed peptides, and at this point, it is claimed that these peptides are safe to be tested and will not cause any response that is unintentional.…”