E2 proteins of high risk human papillomaviruses down-modulate STING and IFN-κ transcription in keratinocytes

Nuchsupha Sunthamala; Francoise Thierry; Sebastien Teissier; Chamsai Pientong; Bunkerd Kongyingyoes; Thumwadee Tangsiriwatthana; Ussanee Sangkomkamhang; Tipaya Ekalaksananan

doi:10.1371/journal.pone.0091473

E2 proteins of high risk human papillomaviruses down-modulate STING and IFN-κ transcription in keratinocytes

PLoS One. 2014 Mar 10;9(3):e91473. doi: 10.1371/journal.pone.0091473. eCollection 2014.

Authors

Nuchsupha Sunthamala¹, Francoise Thierry², Sebastien Teissier², Chamsai Pientong³, Bunkerd Kongyingyoes⁴, Thumwadee Tangsiriwatthana⁵, Ussanee Sangkomkamhang⁵, Tipaya Ekalaksananan³

Affiliations

¹ Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Papillomavirus Regulation and Cancer, Institute of Medical Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
² Papillomavirus Regulation and Cancer, Institute of Medical Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
³ Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
⁴ Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
⁵ Department of Obstetrics and Gynecology, Khon Kaen Hospital, Khon Kaen, Thailand.

Abstract

In the early stages of human papillomavirus (HPV) infection, the viral proteins elicit specific immune responses that can participate to regression of ano-genital lesions. HPV E6 protein for instance can reduce type I interferon (IFN) including IFN-κ that is involved in immune evasion and HPV persistence. To evaluate the role of E2 protein in innate immunity in HPV16-associated cervical lesions, genome-wide expression profiling of human primary keratinocytes (HPK) transduced by HPV16 E2 was investigated using microarrays and innate immunity associated genes were specifically analyzed. The analyses showed that the expression of 779 genes was modulated by HPV16E2 and 92 of them were genes associated with innate immunity. Notably IFN-κ and STING were suppressed in HPK expressing the E2 proteins of HPV16 or HPV18 and the trans-activation amino-terminal domain of E2 was involved in the suppressive effect. The relationship between STING, IFN-κ and interferon stimulated genes (ISGs) in HPK was confirmed by gene silencing and real time PCR. The expression of STING and IFN-κ were further determined in clinical specimens by real time PCR. STING and IFN-κ were down-modulated in HPV positive low grade squamous intraepithelial lesions compared with HPV negative controls. This study demonstrates that E2 proteins of high risk HPV reduce STING and IFN-κ transcription and its downstream target genes that might be an immune evasion mechanism involved in HPV persistence and cervical cancer development.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adenoviridae / metabolism
Cells, Cultured
DNA-Binding Proteins / chemistry
DNA-Binding Proteins / metabolism*
Down-Regulation* / drug effects
Female
Gene Regulatory Networks
Genome, Human / genetics
Green Fluorescent Proteins / metabolism
Humans
Interferon Type I / genetics*
Interferon Type I / metabolism
Keratinocytes / drug effects
Keratinocytes / metabolism*
Membrane Proteins / genetics*
Membrane Proteins / metabolism
Oncogene Proteins, Viral / chemistry
Oncogene Proteins, Viral / metabolism*
Poly I-C / pharmacology
Protein Structure, Tertiary
RNA, Messenger / genetics
RNA, Messenger / metabolism
Recombinant Fusion Proteins / metabolism
Recombination, Genetic
Transcription, Genetic* / drug effects
Transduction, Genetic

Substances

DNA-Binding Proteins
E2 protein, Human papillomavirus type 16
Interferon Type I
Membrane Proteins
Oncogene Proteins, Viral
RNA, Messenger
Recombinant Fusion Proteins
STING1 protein, human
interferon kappa
oncogene protein E2, Human papillomavirus type 18
Green Fluorescent Proteins
Poly I-C

Grants and funding

This work was supported by grants from the Faculty of Medicine (I54328), Khon Kaen University (551602, 564102 and 573002) and the Thailand Research Fund through the Royal Golden Jubilee Ph.D. Program (#PHD/0213/2550) to student’s NS and advisor’s TE is acknowledged. The funders had no role in study design, data collection, data analysis, preparation of manuscript and decision to publish.