Characterization of dengue complex-reactive epitopes on dengue 3 virus envelope protein domain III

Abstract

The disease dengue (DEN) is caused by four genetically and serologically related viruses termed DENV-1, -2, -3, and -4. The DENV envelope (E) protein ectodomain can be divided into three structural domains designated ED1, ED2, and ED3. The ED3 contains the DENV type-specific and DENV complex-reactive (epitopes shared by DENV 1-4) antigenic sites. In this study the epitopes recognized by four DENV complex-reactive monoclonal antibodies (MAbs) with neutralizing activity were mapped on the DENV-3 ED3 using a combination of physical and biological techniques. Amino acid residues L306, K308, G381, I387, and W389 were critical for all four MAbs, with residues V305, E309, V310, K325, D382, A384, K386, and R391 being critical for various subsets of the MAbs. A previous study by our group (Gromowski, G.D., Barrett, N.D., Barrett, A.D., 2008. Characterization of dengue complex-specific neutralizing epitopes on the envelope protein domain III of dengue 2 virus. J. Virol 82, 8828-8837) characterized the same panel of MAbs with DENV-2. The location of the DENV complex-reactive antigenic site on the DENV-2 and DENV-3 ED3s is similar; however, the critical residues for binding are not identical. Overall, this indicates that the DENV complex-reactive antigenic site on ED3 may be similar in location, but the surprising result is that DENV 2 and 3 exhibit unique sets of residues defining the energetics of interaction to the same panel of MAbs. These results imply that the amino acid sequences of DENV define a unique interaction network among these residues in spite of the fact that all flavivirus ED3s to date assume the same structural fold.

Genotype-Specific Neutralization and Protection by Antibodies against Dengue Virus Type 3

“…These regions were described as recognition sites for other subcomplex-or complex-specific neutralizing MAbs against DENV (16,27,30,31,42,53,56). It is interesting to note that these two MAbs, despite binding multiple DENV serotypes, still failed to neutralize efficiently all of the genotypes within the DENV-3 serotype.…”

Human Monoclonal Antibodies against West Nile Virus Induced by Natural Infection Neutralize at a Postattachment Step

“…The lack of an identification of an escape mutant in the highly conserved C-terminal regions could be due to a poor viability of these variants. Unfortunately, because these MAbs bind poorly to recombinant E proteins, cocrystallography (44,57), nuclear magnetic resonance (82), or saturation mutagenesis (23,24,46) approaches to identify the structural epitope are not possible. Instead, cryo-electron microscopy studies with Fab-virion complexes (31,44) are planned to confirm the location of the epitope on the virion.…”

Secretion of dengue virus envelope protein ectodomain from mammalian cells is dependent on domain II serotype and affects the immune response upon DNA vaccination

“…While neutralizing epitopes have been found on all three domains and on the dimer interface Rothman, 2011;Rouvinski et al, 2015;Sukupolvi-Petty et al, 2010), antibodies against the upper lateral surface of DIII are described as the ones with the highest neutralizing capacity (Crill & Roehrig, 2001;Gromowski et al, 2008;Lok et al, 2008;Matsui et al, 2009). We have recently shown that DNA vaccination with DIII-based constructs of all four serotypes results in highly serotype-specific neutralizing responses without induction of antibody-dependent enhancement of infection (Poggianella et al, 2015).…”