Development of a Humanized Antibody with High Therapeutic Potential against Dengue Virus Type 2

Abstract

BackgroundDengue virus (DENV) is a significant public health threat in tropical and subtropical regions of the world. A therapeutic antibody against the viral envelope (E) protein represents a promising immunotherapy for disease control.Methodology/Principal FindingsWe generated seventeen novel mouse monoclonal antibodies (mAbs) with high reactivity against E protein of dengue virus type 2 (DENV-2). The mAbs were further dissected using recombinant E protein domain I-II (E-DI-II) and III (E-DIII) of DENV-2. Using plaque reduction neutralization test (PRNT) and mouse protection assay with lethal doses of DENV-2, we identified four serotype-specific mAbs that had high neutralizing activity against DENV-2 infection. Of the four, E-DIII targeting mAb DB32-6 was the strongest neutralizing mAb against diverse DENV-2 strains. Using phage display and virus-like particles (VLPs) we found that residue K310 in the E-DIII A-strand was key to mAb DB32-6 binding E-DIII. We successfully converted DB32-6 to a humanized version that retained potency for the neutralization of DENV-2 and did not enhance the viral infection. The DB32-6 showed therapeutic efficacy against mortality induced by different strains of DENV-2 in two mouse models even in post-exposure trials.Conclusions/SignificanceWe used novel epitope mapping strategies, by combining phage display with VLPs, to identify the important A-strand epitopes with strong neutralizing activity. This study introduced potential therapeutic antibodies that might be capable of providing broad protection against diverse DENV-2 infections without enhancing activity in humans.

Comprehensive mapping of functional epitopes on dengue virus glycoprotein E DIII for binding to broadly neutralizing antibodies 4E11 and 4E5A by phage display

“…However, potent bNAbs against other regions of the glycoprotein, such as the glycoprotein prefusion dimer interface, arise during the course of natural human infection (Austin et al, 2012; Beltramello et al, 2010; Brien et al, 2010; Dejnirattisai et al, 2015; Edeling et al, 2014; Gentry et al, 1982; Gromowski et al, 2010; Henchal et al, 1985; Kaufman et al, 1987; Li et al, 2012; Lok et al, 2008; Megret et al, 1992; Roehrig et al, 1998; Rouvinski et al, 2015; Shrestha et al, 2010; Sukupolvi-Petty et al, 2007; Wahala and de Silva, 2011; Williams et al, 2012). Glycoprotein E mediates entry into host cells and is located on the surface of the virus in an array of 90 homodimers parallel to the virus membrane (Figure 1A) (Kuhn et al, 2002).…”

Identification of a novel infection-enhancing epitope on dengue prM using a dengue cross-reacting monoclonal antibody

“…Therefore, the identification of B-cell epitopes for DENV prM antibodies can provide important information for the understanding of the pathogenesis of DENV infection and contribute to the development of dengue vaccine. In the case of DENV, many efforts have been made into mapping the epitopes of E protein [35-39], but only a few epitopes have been identified on prM protein [40,41]. Consequently, the precise antigenic structures of prM and their functions in the immune response and infection pathogenesis remain poorly studied.…”

A Mouse Monoclonal Antibody against Dengue Virus Type 1 Mochizuki Strain Targeting Envelope Protein Domain II and Displaying Strongly Neutralizing but Not Enhancing Activity

“…One type-specific, strongly neutralizing human MAb has been found to recognize a quaternary structure epitope mapped to the hinge region between EDI and EDII (23). Several neutralizing human or humanized MAbs targeting EDI/II have also been reported (24)(25)(26)(27)(28).…”