title: Suppression of lytic replication of Kaposi's sarcoma-associated herpesvirus by autophagy during initial infection in NIH 3T3 fibroblasts.
abstract: Kaposi's sarcoma-associated herpesvirus (KSHV) is the infectious cause of the angioproliferative neoplasm Kaposi's sarcoma (KS). We first confirmed the susceptibility of NIH 3T3 fibroblasts to KSHV by infecting them with BCP-1-derived KSHV. Lytic replication of KSHV was confirmed by PCR amplification of viral DNA isolated from culture supernatants of KSHV-infected cells. The template from KSHV-infected NIH 3T3 cells resulted in an intense viral DNA PCR product. A time course experiment revealed the disappearance of KSHV-specific DNA in culture supernatant of NIH 3T3 cells during a period between 48 h and 72 h postinfection. Furthermore, 3 days postinfection, infected NIH 3T3 cells showed no evidence of latent or lytic transcripts, including LANA, vFLIP, vCyclin, and vIL-6. These results imply that KSHV infection in NIH 3T3 cells is unstable and is rapidly lost on subsequent culturing. Additionally, we detected an enhancement of autophagy early in infection with KSHV. More interestingly, inhibition of autophagy by Beclin 1 siRNA or 3-methyladenine significantly increased the amount of KSHV-specific DNA in the culture supernatant of NIH 3T3 cells when compared to the group treated with KSHV infection alone, implying that autophagy prevents lytic replication of KSHV. Taken together, our data suggest that autophagy could be one of the cellular mechanisms utilized by host cells to promote viral clearance.
authors.affiliation: Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 406-772, Korea.
authors.forename: Gun-Hee
authors.initials: GH
authors.lastname: Jang
authors.affiliation: Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 406-772, Korea.
authors.forename: Jihui
authors.initials: J
authors.lastname: Lee
authors.affiliation: Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 406-772, Korea.
authors.forename: Na-Yeon
authors.initials: NY
authors.lastname: Kim
authors.affiliation: Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 406-772, Korea.
authors.forename: Jae-Hyeon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 406-772, Korea.|Institute for New Drug Development, Incheon National University, Incheon, 406-772, Korea.
authors.forename: Jung-Yong
authors.initials: JY
authors.lastname: Yeh
authors.affiliation: Division of Mechanical Engineering, College of Engineering, Incheon National University, Incheon, 406-772, Korea.
authors.forename: Minsub
authors.initials: M
authors.lastname: Han
authors.affiliation: Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 406-772, Korea.|Institute for New Drug Development, Incheon National University, Incheon, 406-772, Korea.
authors.forename: Soon Kil
authors.initials: SK
authors.lastname: Ahn
authors.affiliation: Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 406-772, Korea. harakang@inu.ac.kr.|Institute for New Drug Development, Incheon National University, Incheon, 406-772, Korea. harakang@inu.ac.kr.
authors.forename: Hara
authors.initials: H
authors.lastname: Kang
authors.affiliation: Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 406-772, Korea. mikelee@inu.ac.kr.|Institute for New Drug Development, Incheon National University, Incheon, 406-772, Korea. mikelee@inu.ac.kr.
authors.forename: Michael
authors.initials: M
authors.lastname: Lee
mesh_terms: D000818:Animals; D001343:Autophagy; D004279:DNA, Viral / Q000032:analysis; D005347:Fibroblasts / Q000821:virology*; D019288:Herpesvirus 8, Human / Q000276:immunology* / Q000502:physiology*; D051379:Mice; D041681:NIH 3T3 Cells; D016133:Polymerase Chain Reaction; D013997:Time Factors; D014779:Virus Replication
chemical_list: D004279:DNA, Viral