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HCMV protein LUNA is required for viral reactivation from latently infected primary CD14? cells.

ABSTRACT: Human cytomegalovirus (HCMV) is a member of the Herpesviridae family that infects individuals throughout the world. Following an initial lytic stage, HCMV can persist in the individual for life in a non-active (or latent) form. During latency, the virus resides within cells of the myeloid lineage. The mechanisms controlling HCMV latency are not completely understood. A latency associated transcript, UL81-82ast, encoding the protein LUNA (Latency Unique Natural Antigen) was identified from latently infected donors in vivo. To address the role of the UL81-82ast protein product LUNA, in the context of the viral genome, we developed a recombinant HCMV bacterial artificial chromosome (BAC) that does not express LUNA. This construct, LUNA knockout FIX virus (FIX-?LUNA), was used to evaluate LUNA's role in HCMV latency. The FIX-?LUNA virus was able to lytically infect Human Fibroblast (HF) cells, showing that LUNA is not required to establish a lytic infection. Interestingly, we observed significantly higher viral copy numbers in HF cells infected with FIX-?LUNA when compared to FIX-WT virus. Furthermore, FIX-WT and FIX-?LUNA genomic DNA and transcription of UL81-82ast persisted over time in primary monocytes. In contrast, the levels of UL138 transcript expression in FIX-?LUNA infected HF and CD14? cells was 100 and 1000 fold lower (respectively) when compared to the levels observed for FIX-WT infection. Moreover, FIX-?LUNA virus failed to reactivate from infected CD14? cells following differentiation. This lack of viral reactivation was accompanied by a lack of lytic gene expression, increase in viral copy numbers, and lack of the production of infectious units following differentiation of the cells. Our study suggests that the LUNA protein is involved in regulating HCMV reactivation, and that in the absence of LUNA, HCMV may not be able to enter a proper latent state and therefore cannot be rescued from the established persistent infection in CD14? cells.

SUBMITTER: Keyes LR

PROVIDER: S-EPMC3530514 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

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HCMV protein LUNA is required for viral reactivation from latently infected primary CD14⁺ cells.

Keyes Lisa R LR Hargett Danna D Soland Melisa M Bego Mariana G MG Rossetto Cyprian C CC Almeida-Porada Graca G St Jeor Stephen S

PloS one 20121226 12

Human cytomegalovirus (HCMV) is a member of the Herpesviridae family that infects individuals throughout the world. Following an initial lytic stage, HCMV can persist in the individual for life in a non-active (or latent) form. During latency, the virus resides within cells of the myeloid lineage. The mechanisms controlling HCMV latency are not completely understood. A latency associated transcript, UL81-82ast, encoding the protein LUNA (Latency Unique Natural Antigen) was identified from latent ...[more]

PMID: 23300789

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Dataset Information

HCMV protein LUNA is required for viral reactivation from latently infected primary CD14? cells.

Publications

HCMV protein LUNA is required for viral reactivation from latently infected primary CD14⁺ cells.

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