HPV11 E6 mutation by overexpression of APOBEC3A and effects of interferon-\u03c9 on APOBEC3s and HPV11 E6 expression in HPV11.HaCaT cells

Yongfang Wang,Yang Sun,Xinyu Li,Changming Yu,Shasha Song,Jiafen Zhang,Wei Chen

doi:10.1186/s12985-017-0878-2

Abstract

BackgroundCondyloma acuminatum, infected by low-risk human papillomaviruses (e.g., HPV6 and HPV11), is one of the most widespread sexually transmitted diseases. Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3 proteins (APOBEC3s, A3s) are cellular cytidine deaminases acting as antiviral factors through hypermutation of viral genome. However, it remains unknown whether A3s results in HPV11 gene mutations and interferon-ω (IFN-ω) exhibits antiviral activities through the A3s system. Here we investigated whether enhanced APOBEC3A (A3A) resulted in the E6 gene mutations and explore the effects of recombinant human interferon-ω (rhIFN-ω) on A3s/E6 expression in HaCaT keratinocytes containing the genome of HPV 11 (HPV11.HaCaT cells).MethodsA3A-overexpressed HPV11.HaCaT (A3A-HPV11.HaCaT) cells were established by lentiviral infection and verified by immunofluorescence and western-blotting. Cell cycle, E6 gene mutations, APOBEC3s/E6 gene expression and subcellular localization were detected by FACS, 3D-PCR and sequencing, qRT-PCR and immunofluorescence respectively.ResultsThe results suggested that A3A-HPV11.HaCaT cells were successfully established. Enhanced A3A induced S-phase arrest, G > A/C > T mutations and obvious reduction of E6 mRNA expression. A3A/A3B mRNA expression was up-regulated at 6 h and 12 h and obvious A3A staining existed throughout HPV11.HaCaT cells after rhIFN-ω treatment. RhIFN-ω could also inhibit mRNA expression of HPV11 E6 significantly.ConclusionsEnhanced A3A repressed HPV11 E6 expression through gene hypermutation, and rhIFN-ω might be an effective agent against HPV11 infection by up-regulation of A3A.

Highlights

Condyloma acuminatum, infected by low-risk human papillomaviruses (e.g., HPV6 and HPV11), is one of the most widespread sexually transmitted diseases
Our previous study showed that HPV11 could up-regulate A3s expression in HaCaT keratinocytes containing the genome of Human papillomaviruses (HPVs) 11 (HPV11.HaCaT cells) [23]
The in vitro HPV11.HaCaT system showed that HPV11 could triggered A3s system, suggesting that A3A might be a key factor in HPV11 mutations

Summary

Introduction

Condyloma acuminatum, infected by low-risk human papillomaviruses (e.g., HPV6 and HPV11), is one of the most widespread sexually transmitted diseases. Human papillomaviruses (HPVs) are a group of small, double-stranded DNA viruses and display strict tissue specificity [1] They only infect mucosal or cutaneous epidermal tissues of humans and cause a wide range of apparent epithelial lesions [2]. CA has become one of the most widespread sexually transmitted diseases and present a serious threat to social public health because of the increasing incidence and the high recurrence rate throughout the world [4] It means that HPVs had evolved different ways to avoid detection and clearance by both the innate and adaptive immune system, leading to recurrent and protracted illness [5, 6].

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