Plant-produced anti-dengue virus monoclonal antibodies exhibit reduced antibody-dependent enhancement of infection activity

Abstract

The mAb E60 has the potential to be a desirable therapeutic molecule since it efficiently neutralizes all four serotypes of dengue virus (DENV). However, mammalian-cell-produced E60 exhibits antibody-dependent enhancement of infection (ADE) activity, rendering it inefficacious in vivo, and treated animals more susceptible to developing more severe diseases during secondary infection. In this study, we evaluated a plant-based expression system for the production of therapeutically suitable E60. The mAb was transiently expressed in Nicotiana benthamianaWT and a ∆XFT line, a glycosylation mutant lacking plant-specific N-glycan residues. The mAb was efficiently expressed and assembled in leaves and exhibited highly homogenous N-glycosylation profiles, i.e. GnGnXF3 or GnGn structures, depending on the expression host. Both E60 glycovariants demonstrated equivalent antigen-binding specificity and in vitro neutralization potency against DENV serotypes 2 and 4 compared with their mammalian-cell-produced counterpart. By contrast, plant-produced E60 exhibited reduced ADE activity in Fc gamma receptor expressing human cells. Our results suggest the ability of plant-produced antibodies to minimize ADE, which may lead to the development of safe and highly efficacious antibody-based therapeutics against DENV and other ADE-prone viral diseases. Our study provides so far unknown insight into the relationship between mAb N-glycosylation and ADE, which contributes to our understanding of how sugar moieties of antibodies modulate Fc-mediated functions and viral pathogenesis.

Plant‐produced Zika virus envelope protein elicits neutralizing immune responses that correlate with protective immunity against Zika virus in mice

“…For example, the cost of upstream production can be lowered to $1.00–2.00 per kilogram of protein using plant‐based systems for certain biologics (Nandi et al ., ; Tuse et al ., ). Our results revealed that zE has accumulated rapidly and efficiently in N. benthamiana leaves, with expression levels comparable to that of previously reported plant recombinant proteins that are produced under nonoptimized conditions (Chen and Lai, ; Dent et al ., ). This expression level under a small‐scale laboratory condition can be further increased by process optimization of plant growth conditions and transgene optimization (Lai and Chen, ).…”

“…A PRNT assay was performed as previously described to measure the potency of ZIKV‐specific neutralizing antibodies in mouse sera (Dent et al ., ). Briefly, ZIKV (PRVABC59, ATCC# VR‐1843) was added to twofold serially diluted mouse sera at a concentration of 100 plaque‐forming units (PFU) per well.…”

Immunization of Zika virus envelope protein domain III induces specific and neutralizing immune responses against Zika virus

“…A plaque reduction neutralization test (PRNT) was used to measure ZIKV-specific neutralizing antibodies as previously published [15]. Neutralizing antibody titers were expressed as the reciprocal of the highest dilution of serum that neutralized ≥ 50% of ZIKV.…”

“…Neutralizing antibody titers were expressed as the reciprocal of the highest dilution of serum that neutralized ≥ 50% of ZIKV. The enhancing activities of zEDIII-elicited antibodies for DENV infection was determined by an antibody-dependent enhancement (ADE) assay as previously described [16]. Details of the PRNT and ADE method are provided in the Supplementary material.…”

Codelivery of improved immune complex and virus-like particle vaccines containing Zika virus envelope domain III synergistically enhances immunogenicity

“…The PRNT assay was performed as described previously [33]. Briefly, mouse sera from each group were pooled, heat inactivated, and diluted at 1:10 or 1:50 in Opti-Mem media (Invitrogen).…”