| First Author | Niemeyer BF | Year | 2021 |
| Journal | PLoS Pathog | Volume | 17 |
| Issue | 11 | Pages | e1010019 |
| PubMed ID | 34780571 | Mgi Jnum | J:315187 |
| Mgi Id | MGI:6830806 | Doi | 10.1371/journal.ppat.1010019 |
| Citation | Niemeyer BF, et al. (2021) The gammaherpesvirus 68 viral cyclin facilitates expression of LANA. PLoS Pathog 17(11):e1010019 |
| abstractText | Gammaherpesviruses establish life-long infections within their host and have been shown to be the causative agents of devastating malignancies. Chronic infection within the host is mediated through cycles of transcriptionally quiescent stages of latency with periods of reactivation into detectable lytic and productive infection. The mechanisms that regulate reactivation from latency remain poorly understood. Previously, we defined a critical role for the viral cyclin in promoting reactivation from latency. Disruption of the viral cyclin had no impact on the frequency of cells containing viral genome during latency, yet it remains unclear whether the viral cyclin influences latently infected cells in a qualitative manner. To define the impact of the viral cyclin on properties of latent infection, we utilized a viral cyclin deficient variant expressing a LANA-beta-lactamase fusion protein (LANA::betala), to enumerate both the cellular distribution and frequency of LANA gene expression. Disruption of the viral cyclin did not affect the cellular distribution of latently infected cells, but did result in a significant decrease in the frequency of cells that expressed LANA::betala across multiple tissues and in both immunocompetent and immunodeficient hosts. Strikingly, whereas the cyclin-deficient virus had a reactivation defect in bulk culture, sort purified cyclin-deficient LANA::betala expressing cells were fully capable of reactivation. These data emphasize that the gammaHV68 latent reservoir is comprised of at least two distinct stages of infection characterized by differential LANA expression, and that a primary function of the viral cyclin is to promote LANA expression during latency, a state associated with ex vivo reactivation competence. |
