Merkel cell polyomavirus protein ALTO modulates TBK1 activity to support persistent infection.

While Merkel cell polyomavirus (MCPyV or MCV) is an abundant virus frequently shed from healthy skin, it is one of the most lethal tumor viruses in immunocompromised individuals, highlighting the crucial role of host immunity in controlling MCPyV oncogenic potential. Despite its prevalence, very lit...

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Main Authors: Ranran Wang, Taylor E Senay, Tiana T Luo, Wei Liu, James M Regan, Nicholas J H Salisbury, Denise A Galloway, Jianxin You
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2024-07-01
Series:PLoS Pathogens
Online Access:https://doi.org/10.1371/journal.ppat.1012170
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author Ranran Wang
Taylor E Senay
Tiana T Luo
Wei Liu
James M Regan
Nicholas J H Salisbury
Denise A Galloway
Jianxin You
author_facet Ranran Wang
Taylor E Senay
Tiana T Luo
Wei Liu
James M Regan
Nicholas J H Salisbury
Denise A Galloway
Jianxin You
author_sort Ranran Wang
collection DOAJ
description While Merkel cell polyomavirus (MCPyV or MCV) is an abundant virus frequently shed from healthy skin, it is one of the most lethal tumor viruses in immunocompromised individuals, highlighting the crucial role of host immunity in controlling MCPyV oncogenic potential. Despite its prevalence, very little is known about how MCPyV interfaces with the host immune response to maintain asymptomatic persistent infection and how inadequate control of MCPyV infection triggers MCC tumorigenesis. In this study, we discovered that the MCPyV protein, known as the Alternative Large Tumor Open Reading Frame (ALTO), also referred to as middle T, effectively primes and activates the STING signaling pathway. It recruits Src kinase into the complex of STING downstream kinase TBK1 to trigger its autophosphorylation, which ultimately activates the subsequent antiviral immune response. Combining single-cell analysis with both loss- and gain-of-function studies of MCPyV infection, we demonstrated that the activity of ALTO leads to a decrease in MCPyV replication. Thus, we have identified ALTO as a crucial viral factor that modulates the STING-TBK1 pathway, creating a negative feedback loop that limits viral infection and maintains a delicate balance with the host immune system. Our study reveals a novel mechanism by which a tumorigenic virus-encoded protein can link Src function in cell proliferation to the activation of innate immune signaling, thereby controlling viral spread, and sustaining persistent infection. Our previous findings suggest that STING also functions as a tumor suppressor in MCPyV-driven oncogenesis. This research provides a foundation for investigating how disruptions in the finely tuned virus-host balance, maintained by STING, could alter the fate of MCPyV infection, potentially encouraging malignancy.
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spelling doaj-art-90da2940d66a4e6691ecc6d3a55396a92025-01-10T05:31:49ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742024-07-01207e101217010.1371/journal.ppat.1012170Merkel cell polyomavirus protein ALTO modulates TBK1 activity to support persistent infection.Ranran WangTaylor E SenayTiana T LuoWei LiuJames M ReganNicholas J H SalisburyDenise A GallowayJianxin YouWhile Merkel cell polyomavirus (MCPyV or MCV) is an abundant virus frequently shed from healthy skin, it is one of the most lethal tumor viruses in immunocompromised individuals, highlighting the crucial role of host immunity in controlling MCPyV oncogenic potential. Despite its prevalence, very little is known about how MCPyV interfaces with the host immune response to maintain asymptomatic persistent infection and how inadequate control of MCPyV infection triggers MCC tumorigenesis. In this study, we discovered that the MCPyV protein, known as the Alternative Large Tumor Open Reading Frame (ALTO), also referred to as middle T, effectively primes and activates the STING signaling pathway. It recruits Src kinase into the complex of STING downstream kinase TBK1 to trigger its autophosphorylation, which ultimately activates the subsequent antiviral immune response. Combining single-cell analysis with both loss- and gain-of-function studies of MCPyV infection, we demonstrated that the activity of ALTO leads to a decrease in MCPyV replication. Thus, we have identified ALTO as a crucial viral factor that modulates the STING-TBK1 pathway, creating a negative feedback loop that limits viral infection and maintains a delicate balance with the host immune system. Our study reveals a novel mechanism by which a tumorigenic virus-encoded protein can link Src function in cell proliferation to the activation of innate immune signaling, thereby controlling viral spread, and sustaining persistent infection. Our previous findings suggest that STING also functions as a tumor suppressor in MCPyV-driven oncogenesis. This research provides a foundation for investigating how disruptions in the finely tuned virus-host balance, maintained by STING, could alter the fate of MCPyV infection, potentially encouraging malignancy.https://doi.org/10.1371/journal.ppat.1012170
spellingShingle Ranran Wang
Taylor E Senay
Tiana T Luo
Wei Liu
James M Regan
Nicholas J H Salisbury
Denise A Galloway
Jianxin You
Merkel cell polyomavirus protein ALTO modulates TBK1 activity to support persistent infection.
PLoS Pathogens
title Merkel cell polyomavirus protein ALTO modulates TBK1 activity to support persistent infection.
title_full Merkel cell polyomavirus protein ALTO modulates TBK1 activity to support persistent infection.
title_fullStr Merkel cell polyomavirus protein ALTO modulates TBK1 activity to support persistent infection.
title_full_unstemmed Merkel cell polyomavirus protein ALTO modulates TBK1 activity to support persistent infection.
title_short Merkel cell polyomavirus protein ALTO modulates TBK1 activity to support persistent infection.
title_sort merkel cell polyomavirus protein alto modulates tbk1 activity to support persistent infection
url https://doi.org/10.1371/journal.ppat.1012170
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