Mapping the Human Memory B Cell and Serum Neutralizing Antibody Responses to Dengue Virus Serotype 4 Infection and Vaccination

Abstract

The four dengue virus (DENV) serotypes are mosquito-borne flaviviruses responsible for dengue fever and dengue hemorrhagic fever. People exposed to DENV develop antibodies (Abs) that strongly neutralize the serotype responsible for infection. Historically, infection with DENV serotype 4 (DENV4) has been less common and less studied than infections with the other three serotypes. However, DENV4 has been responsible for recent large and sustained epidemics in Asia and Latin America. The neutralizing antibody responses and the epitopes targeted against DENV4 have not been characterized in human infection. In this study, we mapped and characterized epitopes on DENV4 recognized by neutralizing antibodies in people previously exposed to DENV4 infections or to a live attenuated DENV4 vaccine. To study the fine specificity of DENV4 neutralizing human antibodies, B cells from two people exposed to DENV4 were immortalized and screened to identify DENV-specific clones. Two human monoclonal antibodies (MAbs) that neutralized DENV4 were isolated, and their epitopes were finely mapped using recombinant viruses and alanine scan mutation array techniques. Both antibodies bound to quaternary structure epitopes near the hinge region between envelope protein domain I (EDI) and EDII. In parallel, to characterize the serum neutralizing antibody responses, convalescence-phase serum samples from people previously exposed to primary DENV4 natural infections or a monovalent DENV4 vaccine were analyzed. Natural infection and vaccination also induced serum-neutralizing antibodies that targeted similar epitope domains at the EDI/II hinge region. These studies defined a target of neutralizing antigenic site on DENV4 targeted by human antibodies following natural infection or vaccination.IMPORTANCE The four serotypes of dengue virus are the causative agents of dengue fever and dengue hemorrhagic fever. People exposed to primary DENV infections develop long-term neutralizing antibody responses, but these principally recognize only the infecting serotype. An effective vaccine against dengue should elicit long-lasting protective antibody responses to all four serotypes simultaneously. We and others have defined antigenic sites on the envelope (E) protein of viruses of dengue virus serotypes 1, 2, and 3 targeted by human neutralizing antibodies. The

Viral genetic diversity and protective efficacy of a tetravalent dengue vaccine in two phase 3 trials

“…S9). Four influential positions reside in mapped epitope regions of two recently isolated DENV4specific human monoclonal NAbs DV4-126 and DV4-131, and, of those, three positions (E46, E120, and E203) are proximal to the residues K51, V53, K124, K200, and K202 in the E protein's DI/II hinge and domain DII identified as critical for DV4-126 and DV4-131 binding to DENV4 (the critical residues were perfectly matched in all DENV4 breakthrough sequences) (23). Fig.…”

“…Locations of DENV4 signature amino acid sites and the epitopes of DENV4-neutralizing monoclonal antibodies. The amino acids at the five DENV4 signature sites located in the ectodomain and the residues in the footprint of one or more DENV4-specific monoclonal antibodies (D4-126, D4-131, and 5H2) (23,24) are shown on one monomer of the DENV E protein dimer (Protein Databank ID code 1OAN). Residues common to both the D4-126 and D4-131 epitopes are shown in orange, and the amino acids at signature sites present in the 5H2 epitope are shown in light blue.…”

Human antibody response to Zika targets type-specific quaternary structure epitopes

“…BOB was performed as described previously (79). Briefly, ZIKV was captured using 4G2 and plates were blocked with 3% nonfat dry milk as for ELISA.…”

Alanine Substitution Inactivates Cross-Reacting Epitopes in Dengue Virus Recombinant Envelope Proteins

“…Four serotypes of Dengue viruses (DENV1 through DENV4) have been identified. In naturally occurring infections, acquired immunity against one serotype rarely protects against a subsequent secondary infection by any of the other serotypes [3][4][5], but the presence of circulating, non-neutralizing antibodies against any of the serotypes increases the risk of severe hemorrhagic fever/shock syndrome in patients infected by a different serotype in a secondary or concurrent exposure [4][5][6].…”