A BMPR2/YY1 Signaling Axis Is Required for Human Cytomegalovirus Latency in Undifferentiated Myeloid Cells.

Emma Poole,Maria Cristina Carlan Da Silva,Ian J Groves,Sarah Jackson,Chris Huang,John Sinclair,Mark Wills,Amer Rana,Marianne Perera,Blossom Damania,Robert F Kalejta

doi:10.1128/mbio.00227-21

Emma Poole, Maria Cristina Carlan Da Silva + Show 9 more

Open Access

https://doi.org/10.1128/mbio.00227-21

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Journal: mBio	Publication Date: Jun 1, 2021
Citations: 12	License type: CC BY 4.0

Affiliation: University of Cambridge, Universidade Federal do ABC

Abstract

ABSTRACTHuman cytomegalovirus (HCMV) presents a major health burden in the immunocompromised and in stem cell transplant medicine. A lack of understanding about the mechanisms of HCMV latency in undifferentiated CD34+ stem cells, and how latency is broken for the virus to enter the lytic phase of its infective cycle, has hampered the development of essential therapeutics. Using a human induced pluripotent stem cell (iPSC) model of HCMV latency and patient-derived myeloid cell progenitors, we demonstrate that bone morphogenetic protein receptor type 2 (BMPR2) is necessary for HCMV latency. In addition, we define a crucial role for the transcription factor Yin Yang 1 (YY1) in HCMV latency; high levels of YY1 are maintained in latently infected cells as a result of BMPR2 signaling through the SMAD4/SMAD6 axis. Activation of SMAD4/6, through BMPR2, inhibits TGFbeta receptor signaling, which leads to the degradation of YY1 via induction of a cellular microRNA (miRNA), hsa-miR-29a. Pharmacological targeting of BMPR2 in progenitor cells results in the degradation of YY1 and an inability to maintain latency and renders cells susceptible to T cell killing. These data argue that BMPR2 plays a role in HCMV latency and is a new potential therapeutic target for maintaining or disrupting HCMV latency in myeloid progenitors.

Highlights

Human cytomegalovirus (HCMV) presents a major health burden in the immunocompromised and in stem cell transplant medicine
IE2-yellow fluorescent protein (YFP) expression was not observed in WT- and Cas9-induced pluripotent stem cell (iPSC) but was clearly observed in Yin Yang 1 (YY1)-KO iPSCs, and this was equivalent to levels observed in differentiated WT-iPSCs (Fig. 1C, panel a; a graphical representation of these data is shown in Fig. 1C, panel b)
This was validated using reverse transcription-quantitative PCR (RT-qPCR) (Fig. 1D), which showed that infected YY1-KO iPSCs had levels of immediate early (IE) RNA comparable to levels observed in infected WT-iPSCs which had been differentiated with phorbol myristate acetate (PMA); this was in contrast to the case with infected undifferentiated WT-iPSCs, which showed detectable levels of UL138 expression in the relative absence of IE, a characteristic of latent infection

Summary

Introduction

Human cytomegalovirus (HCMV) presents a major health burden in the immunocompromised and in stem cell transplant medicine. This work identifies key host-virus interactions which regulate HCMV latent infection It demonstrates a potential new therapeutic approach to reduce HCMV reactivation-mediated disease by the treatment of donor stem cells/organs prior to transplantation, which could have a major impact in the transplant disease setting. One established model of HCMV latency is in the myeloid lineage, where undifferentiated myeloid cells support latency but, upon differentiation of these cells to terminally differentiated macrophages or dendritic cells (DCs), IE gene expression is initiated, leading to the full lytic life cycle and production of infectious virions [4,5,6,7]. Induced pluripotent stem cell (iPSC) models, which allow the culture of renewable populations of undifferentiated cells which can be differentiated along multiple lineages, have been used successfully to study HCMV latent infection and reactivation [14,15,16]

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