Epstein-Barr virus infection-induced inflammasome activation in human monocytes

Yuka Torii, Jun Ichi Kawada, Takayuki Murata, Hironori Yoshiyama, Hiroshi Kimura, Yoshinori Ito

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Inflammasomes are cytoplasmic sensors that regulate the activity of caspase-1 and the secretion of interleukin-1β (IL-1β) or interleukin-18 (IL-18) in response to foreign molecules, including viral pathogens. They are considered to be an important link between the innate and adaptive immune responses. However, the mechanism by which inflammasome activation occurs during primary Epstein-Barr virus (EBV) infection remains unknown. Human B lymphocytes and epithelial cells are major targets of EBV, although it can also infect a variety of other cell types. In this study, we found that EBV could infect primary human monocytes and the monocyte cell line, THP-1, inducing inflammasome activation. We incubated cell-free EBV with THP-1 cells or primary human monocytes, then confirmed EBV infection using confocal microscopy and flow cytometry. Lytic and latent EBV genes were detected by real-time RT-PCR in EBV-infected monocytes. EBV infection of THP-1 cells and primary human monocytes induced caspase-dependent IL-1β production, while EBV infection of B-cell or T-cell lines did not induce IL-1β production. To identify the sensor molecule responsible for inflammasome activation during EBV infection, we examined the mRNA and the protein levels of NLR family pyrin domain-containing 3(NLRP3), absent in melanoma 2(AIM2), and interferon-inducible protein 16 (IFI16). Increased AIM2 levels were observed in EBV-infected THP-1 cells and primary human monocytes, whereas levels of IFI16 and NLRP3 did not show remarkable change. Furthermore, knockdown of AIM2 by small interfering RNA attenuated caspase-1 activation. Taken together, our results suggest that EBV infection of human monocytes induces caspase-1-dependent IL-1β production, and that AIM2, acting as an inflammasome, is involved in this response.

Original languageEnglish
Article numbere0175053
JournalPloS one
Volume12
Issue number4
DOIs
Publication statusPublished - 01-03-2017
Externally publishedYes

Fingerprint

Inflammasomes
Human herpesvirus 4
Epstein-Barr Virus Infections
Viruses
monocytes
Monocytes
Human Herpesvirus 4
Chemical activation
Interleukin-1
Caspase 1
Melanoma
infection
interleukin-1
caspase-1
melanoma
Interferons
B-Lymphocytes
Cell Line
interferons
Interleukin-18

All Science Journal Classification (ASJC) codes

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

Torii, Yuka ; Kawada, Jun Ichi ; Murata, Takayuki ; Yoshiyama, Hironori ; Kimura, Hiroshi ; Ito, Yoshinori. / Epstein-Barr virus infection-induced inflammasome activation in human monocytes. In: PloS one. 2017 ; Vol. 12, No. 4.
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abstract = "Inflammasomes are cytoplasmic sensors that regulate the activity of caspase-1 and the secretion of interleukin-1β (IL-1β) or interleukin-18 (IL-18) in response to foreign molecules, including viral pathogens. They are considered to be an important link between the innate and adaptive immune responses. However, the mechanism by which inflammasome activation occurs during primary Epstein-Barr virus (EBV) infection remains unknown. Human B lymphocytes and epithelial cells are major targets of EBV, although it can also infect a variety of other cell types. In this study, we found that EBV could infect primary human monocytes and the monocyte cell line, THP-1, inducing inflammasome activation. We incubated cell-free EBV with THP-1 cells or primary human monocytes, then confirmed EBV infection using confocal microscopy and flow cytometry. Lytic and latent EBV genes were detected by real-time RT-PCR in EBV-infected monocytes. EBV infection of THP-1 cells and primary human monocytes induced caspase-dependent IL-1β production, while EBV infection of B-cell or T-cell lines did not induce IL-1β production. To identify the sensor molecule responsible for inflammasome activation during EBV infection, we examined the mRNA and the protein levels of NLR family pyrin domain-containing 3(NLRP3), absent in melanoma 2(AIM2), and interferon-inducible protein 16 (IFI16). Increased AIM2 levels were observed in EBV-infected THP-1 cells and primary human monocytes, whereas levels of IFI16 and NLRP3 did not show remarkable change. Furthermore, knockdown of AIM2 by small interfering RNA attenuated caspase-1 activation. Taken together, our results suggest that EBV infection of human monocytes induces caspase-1-dependent IL-1β production, and that AIM2, acting as an inflammasome, is involved in this response.",
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Epstein-Barr virus infection-induced inflammasome activation in human monocytes. / Torii, Yuka; Kawada, Jun Ichi; Murata, Takayuki; Yoshiyama, Hironori; Kimura, Hiroshi; Ito, Yoshinori.

In: PloS one, Vol. 12, No. 4, e0175053, 01.03.2017.

Research output: Contribution to journalArticle

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