Novel differential linear B‐cell epitopes to identify Zika and dengue virus infections in patients

Abstract

Objectives Recent Zika virus (ZIKV) outbreaks challenged existing laboratory diagnostic standards, especially for serology‐based methods. Because of the genetic and structural similarity of ZIKV with other flaviviruses, this results in cross‐reactive antibodies, which confounds serological interpretations. Methods Plasma from Singapore ZIKV patients was screened longitudinally for antibody responses and neutralising capacities against ZIKV. Samples from healthy controls, ZIKV patients and DENV patients were further assessed using ZIKV and DENV peptides of precursor membrane (prM), envelope (E) or non‐structural 1 (NS1) viral proteins in a peptide‐based ELISA for epitope identification. Identified epitopes were re‐validated and diagnostically evaluated using sera of patients with DENV, bacteria or unknown infections from Thailand. Results Long‐lasting ZIKV‐neutralising antibodies were elicited during ZIKV infection. Thirteen potential linear B‐cell epitopes were identified, and of these, four common flavivirus, three ZIKV‐specific and one DENV‐specific differential epitopes had more than 50% sensitivity and specificity. Notably, ZIKV‐specific peptide 26 on domain I/II of E protein (amino acid residues 271–288) presented 80% sensitivity and 85.7% specificity. Importantly, the differential epitopes also showed significance in differentiating non‐flavivirus patient samples. Conclusion Linear B‐cell epitope candidates to differentiate between ZIKV and DENV infections were identified, providing the first step towards the design of a much‐needed serology‐based assay.

Immunoproteomic Approach of Extracellular Antigens From Paracoccidioides Species Reveals Exclusive B-Cell Epitopes

“…Similar analyses have already been performed in other works, where linear B-cell epitopes were employed for serological detection of several pathogenic organisms, such as Borrelia miyamotoiis (Tokarz et al, 2019), Toxoplasma gondii (Gatkowska et al, 2019), Treponema pallidum (Ogden et al, 2019), Leishmania spp. (Bremer Hinckel et al, 2019;Vale et al, 2019), and several human viruses (Amrun et al, 2019;Mutsvunguma et al, 2019;Yao et al, 2019). This reinforces the importance of these analyses, demonstrating the applications of linear B-cell epitopes in the diagnosis of human pathogenic organisms.…”

Linear and Continuous Flavivirus Epitopes From Naturally Infected Humans

“…Pep10 and Pep12 from the JEV capsid protein also show increased cross-detection with antibodies from JEV and DENV1 patients, probably by acting as group-specific antigens (Huang et al, 1996). Peptides from the prM protein (such as Pep14, Pep15, Pep19, Pep20, Pep24, and Pep26) and from the envelope protein (such as Pep29, Pep30, and Pep86 of the DENV and ZIKV) also exhibit cross-detection with antibodies and may act as pan-flavivirus antigens (Amrun et al, 2019;Kam et al, 2019). Similarly, two linear peptides from the prM protein of the WNV (Pep27 and Pep28) were found to show similar cross-detection signals with anti-WNV and anti-JEV from convalescent patient sera (Gangwar et al, 2012).…”

“…A mapping study based on prM protein identified linear reactive peptides from DENV3 and ZIKV using IgG serum samples from convalescent DENV and ZIKV patients (Amrun et al, 2019). Among the reactive peptides, one linear peptide from DENV3 and one from the ZIKV (Pep20, HITEVEPEDID CWCNLT; and Pep24, LDEGVEPDDVDCWCNTT) that reacted with both anti-ZIKV and anti-DENV antibodies were identified as potential common flavivirus-reactive antigens.…”

“…Interestingly, most of the specific DENV3 linear peptides were able to elicit IgG antibody production and induce IFN-g secretion by CD4 + T cells from immunized BALB/c mice after peptide stimulation. Furthermore, another study performed epitope mapping of the DENV3 and ZIKV envelope proteins by ELISA-based screening with overlapping peptides using convalescent sera from ZIKV and DENV patients from Singapore and Thailand (Amrun et al, 2019). A potential DENV-specific peptide (Pep77, YENLKYTVIITVHTGDQH) and two potential ZIKV-specifi c peptides (Pep89, GALEAEMDGAKGRLSSGH; and Pep90: FKSLFGGMSW FSQILIGT) were identified in the envelope protein region that show higher IgG detection levels for sera from convalescent patients than for those from healthy controls.…”

“…Another study performed ELISA epitope mapping and identified five peptides from the Ns1 protein of DENV3 ( P e p 1 2 2 , Q I A N E L N Y I L W E N N I K ; P e p 1 2 3 , G K A K IVTAETQNSSFIID; Pep124, GPNTPECPSASRAWNVWE; P e p 1 2 8 , T V V I T E N C G T R G P S L R T T ; a n d P e p 1 2 9 , SCTLPPLRYMGE) and five peptides from the Ns1 protein of the ZIKV (Pep131, SVEGELNAILEENGVQ; Pep134, GKSYFVR AAKTNNSFVVD; Pep135, GDTLKECPLKHRAWNSFL; P e p 1 4 2 , K V H V E E T C G T R G P S L R S T ; a n d P e p 1 4 3 , ECTMPPLSFRAK) as potential common linear flavivirus recognition peptides (Amrun et al, 2019). These peptides all developed similar detection results with IgG from convalescent ZIKV and DENV patient sera.…”