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Release of human cytomegalovirus from latency by a KAP1/TRIM28 phosphorylation switch.

Rauwel B, Jang SM, Cassano M, Kapopoulou A, Barde I, Trono D - Elife (2015)

Bottom Line: Here, we reveal that HCMV latency in human CD34(+) HSC reflects the recruitment on the viral genome of KAP1, a master co-repressor, together with HP1 and the SETDB1 histone methyltransferase, which results in transcriptional silencing.Correspondingly, HCMV can be forced out of latency by KAP1 knockdown or pharmacological induction of KAP1 phosphorylation, and this process can be potentiated by activating NFkB with TNF-α.These results suggest new approaches both to curtail CMV infection and to purge the virus from organ transplants.

View Article: PubMed Central - PubMed

Affiliation: School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.

ABSTRACT
Human cytomegalovirus (HCMV) is a highly prevalent pathogen that induces life-long infections notably through the establishment of latency in hematopoietic stem cells (HSC). Bouts of reactivation are normally controlled by the immune system, but can be fatal in immuno-compromised individuals such as organ transplant recipients. Here, we reveal that HCMV latency in human CD34(+) HSC reflects the recruitment on the viral genome of KAP1, a master co-repressor, together with HP1 and the SETDB1 histone methyltransferase, which results in transcriptional silencing. During lytic infection, KAP1 is still associated with the viral genome, but its heterochromatin-inducing activity is suppressed by mTOR-mediated phosphorylation. Correspondingly, HCMV can be forced out of latency by KAP1 knockdown or pharmacological induction of KAP1 phosphorylation, and this process can be potentiated by activating NFkB with TNF-α. These results suggest new approaches both to curtail CMV infection and to purge the virus from organ transplants.

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Related in: MedlinePlus

Monocytes do not differentiate during pharmacological reactivation of HCMV.Figure 7 source datas.DOI:http://dx.doi.org/10.7554/eLife.06068.026
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fig7s2: Monocytes do not differentiate during pharmacological reactivation of HCMV.Figure 7 source datas.DOI:http://dx.doi.org/10.7554/eLife.06068.026

Mentions: Monocytes from HCMV seropositive donors were purified and treated three times (Day 0, 3 and 5) or not (NT) with Chloroquine (Chloro) alone in combination with Torin-1 (Torin) or KU59933. (A) HCMV DNA associated with the monocytes was quantified by qPCR, normalizing with the GAPDH and albumin genes. Data are presented as average of three different experiments performed with cells from independent donors. (B) Supernatant from the monocytes, harvested after 7 days of treatment and the viral production was quantified by classical plaque assay on MRC-5 fibroblasts. Results are presented as PFU/ml. Histogram represents an average of three different experiments performed with HSC from three independent donors (n = 3, *p < 0.05, **p < 0.01, error bars as s.d.). See Figure 7—figure supplement 2 for all individual experiments.


Release of human cytomegalovirus from latency by a KAP1/TRIM28 phosphorylation switch.

Rauwel B, Jang SM, Cassano M, Kapopoulou A, Barde I, Trono D - Elife (2015)

Monocytes do not differentiate during pharmacological reactivation of HCMV.Figure 7 source datas.DOI:http://dx.doi.org/10.7554/eLife.06068.026
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4384640&req=5

fig7s2: Monocytes do not differentiate during pharmacological reactivation of HCMV.Figure 7 source datas.DOI:http://dx.doi.org/10.7554/eLife.06068.026
Mentions: Monocytes from HCMV seropositive donors were purified and treated three times (Day 0, 3 and 5) or not (NT) with Chloroquine (Chloro) alone in combination with Torin-1 (Torin) or KU59933. (A) HCMV DNA associated with the monocytes was quantified by qPCR, normalizing with the GAPDH and albumin genes. Data are presented as average of three different experiments performed with cells from independent donors. (B) Supernatant from the monocytes, harvested after 7 days of treatment and the viral production was quantified by classical plaque assay on MRC-5 fibroblasts. Results are presented as PFU/ml. Histogram represents an average of three different experiments performed with HSC from three independent donors (n = 3, *p < 0.05, **p < 0.01, error bars as s.d.). See Figure 7—figure supplement 2 for all individual experiments.

Bottom Line: Here, we reveal that HCMV latency in human CD34(+) HSC reflects the recruitment on the viral genome of KAP1, a master co-repressor, together with HP1 and the SETDB1 histone methyltransferase, which results in transcriptional silencing.Correspondingly, HCMV can be forced out of latency by KAP1 knockdown or pharmacological induction of KAP1 phosphorylation, and this process can be potentiated by activating NFkB with TNF-α.These results suggest new approaches both to curtail CMV infection and to purge the virus from organ transplants.

View Article: PubMed Central - PubMed

Affiliation: School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.

ABSTRACT
Human cytomegalovirus (HCMV) is a highly prevalent pathogen that induces life-long infections notably through the establishment of latency in hematopoietic stem cells (HSC). Bouts of reactivation are normally controlled by the immune system, but can be fatal in immuno-compromised individuals such as organ transplant recipients. Here, we reveal that HCMV latency in human CD34(+) HSC reflects the recruitment on the viral genome of KAP1, a master co-repressor, together with HP1 and the SETDB1 histone methyltransferase, which results in transcriptional silencing. During lytic infection, KAP1 is still associated with the viral genome, but its heterochromatin-inducing activity is suppressed by mTOR-mediated phosphorylation. Correspondingly, HCMV can be forced out of latency by KAP1 knockdown or pharmacological induction of KAP1 phosphorylation, and this process can be potentiated by activating NFkB with TNF-α. These results suggest new approaches both to curtail CMV infection and to purge the virus from organ transplants.

Show MeSH
Related in: MedlinePlus