In vitro Studies and Clinical Observations Imply a Synergistic Effect Between Epstein-Barr Virus and Dengue Virus Infection.

Hua Zhang,Pei Xu,Zhong-Yu Liu,Dan Li,Lei Yu,Xue-Ying Liang,Fu-Chun Zhang,Ling-Zhai Zhao,Xiao-Mei Deng

doi:10.3389/fmicb.2021.691008

Abstract

Dengue virus (DENV) infection can lead to a complex spectrum of clinical outcomes, ranging from asymptomatic infection to life-threatening severe dengue. The reasons for thus drastically varying manifestations of the disease remain an enigma. Herein, we reported an original discovery of the synergistic effect between preexisting Epstein–Barr virus (EBV) infection and DENV superinfection in vitro and of a strong correlation of these two viruses in the clinical samples from dengue patients. We showed that (I) DENV-2 infection of an EBV-positive cell line (EBV + Akata cell) reactivated EBV, and it could be blocked by wortmannin treatment. (II) Examination of human peripheral blood mononuclear cell (PBMC) samples from dengue patients revealed significantly elevated cell-associated EBV DNA copy number at the time of hospitalization vs. at the time of disease recovery in most individuals. (III) EBV infection promoted DENV propagation in both EBV-hosting B cells and indirectly in THP-1 cells, supported by the following evidence: (A) EBV + Akata cells were more permissive to DENV-2 infection compared with Akata cells harboring no EBV virus (EBV- Akata cells). (B) Low-molecular weight fraction secreted from EBV + Akata cells could enhance DENV-2 propagation in monocytic THP-1 cells. (C) While reactivation of EBV in EBV + Akata cells further increased DENV-2 yield from this cell line, pharmacological inhibition of EBV replication by acyclovir had the opposite effect. To our knowledge, this is the first investigation demonstrating a positive correlation between EBV and DENV in vitro and in human biospecimens.

Highlights

Dengue virus (DENV) serotypes 1–4 (DENV-1–DENV-4) caused approximately 390 million human infections globally per year; about 96 million are symptomatic (Bhatt et al, 2013)
We investigated the interplay between Epstein– Barr virus (EBV) and DENV using in vitro systems and clinical samples, and the findings are (I) DENV-2 replication in EBV-positive B cell lines reactivated EBV and/or promoted EBV replication; (II) peripheral blood mononuclear cell (PBMC)-associated EBV copy numbers were significantly elevated at the symptomatic period of dengue patients; (III) preexisting EBV infection could directly facilitate DENV-2 replication in B cells and indirectly promote DENV-2 growth in a monocyte cell line; and (IV) inhibition of EBV replication by acyclovir (ACV) decreased DENV-2 replication in EBV + Akata cells
EBV + Akata cells were infected with DENV-2 at a multiplicity of infection (MOI) of 10, the culture medium was collected at different hpi, and DENV-2 yields were titrated by plaque assay

Summary

Introduction

Dengue virus (DENV) serotypes 1–4 (DENV-1–DENV-4) caused approximately 390 million human infections globally per year; about 96 million are symptomatic (Bhatt et al, 2013). Synergistic Infection Between EBV and Dengue Virus the primary targets of DENV. While circulating monocytes are believed to play a critical role in in vivo spread and pathogenesis of DENV (Jessie et al, 2004; Durbin et al, 2008), primary B and T lymphocytes are shown to be permissive to DENV infection (Lin et al, 2002; Silveira et al, 2018). Though previous studies have shown that both host and virus factors, especially the host immunity status, can influence the outcomes of DENV infection (Katzelnick et al, 2017; Robinson and Einav, 2020), investigations in whether and how persistent infections in human hosts contribute to DENV infection were rare

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