TY - JOUR
T1 - Sirolimus and Other Mechanistic Target of Rapamycin Inhibitors Directly Activate Latent Pathogenic Human Polyomavirus Replication
AU - Alvarez Orellana, Jennifer
AU - Kwun, Hyun Jin
AU - Artusi, Sara
AU - Chang, Yuan
AU - Moore, Patrick S.
N1 - Funding Information:
This study was supported by the National Institutes of Health (grant numbers R35 CA197463 to P. S. M. and CA170354 to Y. C.). P. S. M. and Y. C. are also supported as American Cancer Society research professors and receive support from the Pittsburgh Foundation (to P. S. M.) and the UPMC Foundation (to Y. C.). This project used the University of Pittsburgh Cancer Center's shared resource cores supported, in part, by award number P30CA047904. H. J. K. is supported in part by an institutional research grant (number IRG-17-175-04) from the American Cancer Society and by the Pennsylvania Department of Health Tobacco CURE Funds.
Publisher Copyright:
© 2020 The Author(s). Published by Oxford University Press for the Infectious Diseases Society of America.
PY - 2021/10/1
Y1 - 2021/10/1
N2 - Background: Human polyomaviruses can reactivate in transplant patients, causing nephropathy, progressive multifocal leukoencephalopathy, Merkel cell carcinoma, pruritic, rash or trichodysplasia spinulosa. Sirolimus and related mechanistic target of rapamycin (mTOR) inhibitors are transplant immunosuppressants. It is unknown if they directly reactivate polyomavirus replication from latency beyond their general effects on immunosuppression. Methods: In vitro expression and turnover of large T (LT) proteins from BK virus, JC virus (JCV), Merkel cell polyomavirus (MCV), human polyomavirus 7 (HPyV7), and trichodysplasia spinulosa polyomavirus (TSV) after drug treatment were determined by immunoblotting, proximity ligation, replicon DNA replication, and whole virus immunofluorescence assays. Results: mTOR inhibition increased LT protein expression for all 5 pathogenic polyomaviruses tested. This correlated with LT stabilization, decrease in the S-phase kinase-associated protein 2 (Skp2) E3 ligase targeting these LT proteins for degradation, and increase in virus replication for JCV, MCV, TSV, and HPyV7. Treatment with sirolimus, but not the calcineurin inhibitor tacrolimus, at levels routinely achieved in patients, resulted in a dose-dependent increase in viral DNA replication for BKV, MCV, and HPyV7. Conclusions: mTOR inhibitors, at therapeutic levels, directly activate polyomavirus replication through a Skp2-dependent mechanism, revealing a proteostatic latency mechanism common to polyomaviruses. Modifying existing drug regimens for transplant patients with polyomavirus-associated diseases may reduce symptomatic polyomavirus replication while maintaining allograft-sparing immunosuppression.
AB - Background: Human polyomaviruses can reactivate in transplant patients, causing nephropathy, progressive multifocal leukoencephalopathy, Merkel cell carcinoma, pruritic, rash or trichodysplasia spinulosa. Sirolimus and related mechanistic target of rapamycin (mTOR) inhibitors are transplant immunosuppressants. It is unknown if they directly reactivate polyomavirus replication from latency beyond their general effects on immunosuppression. Methods: In vitro expression and turnover of large T (LT) proteins from BK virus, JC virus (JCV), Merkel cell polyomavirus (MCV), human polyomavirus 7 (HPyV7), and trichodysplasia spinulosa polyomavirus (TSV) after drug treatment were determined by immunoblotting, proximity ligation, replicon DNA replication, and whole virus immunofluorescence assays. Results: mTOR inhibition increased LT protein expression for all 5 pathogenic polyomaviruses tested. This correlated with LT stabilization, decrease in the S-phase kinase-associated protein 2 (Skp2) E3 ligase targeting these LT proteins for degradation, and increase in virus replication for JCV, MCV, TSV, and HPyV7. Treatment with sirolimus, but not the calcineurin inhibitor tacrolimus, at levels routinely achieved in patients, resulted in a dose-dependent increase in viral DNA replication for BKV, MCV, and HPyV7. Conclusions: mTOR inhibitors, at therapeutic levels, directly activate polyomavirus replication through a Skp2-dependent mechanism, revealing a proteostatic latency mechanism common to polyomaviruses. Modifying existing drug regimens for transplant patients with polyomavirus-associated diseases may reduce symptomatic polyomavirus replication while maintaining allograft-sparing immunosuppression.
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U2 - 10.1093/infdis/jiaa071
DO - 10.1093/infdis/jiaa071
M3 - Article
C2 - 32060513
AN - SCOPUS:85118903544
VL - 224
SP - 1160
EP - 1169
JO - Journal of Infectious Diseases
JF - Journal of Infectious Diseases
SN - 0022-1899
IS - 7
ER -