scholarly journals HCMV Infection and Apoptosis: How Do Monocytes Survive HCMV Infection?

Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 533 ◽  
Author(s):  
Donna Collins-McMillen ◽  
Liudmila Chesnokova ◽  
Byeong-Jae Lee ◽  
Heather Fulkerson ◽  
Reynell Brooks ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Survival ◽  
Hcmv Infection ◽  
Viral Gene Expression ◽  
Multiple Organ ◽  
Viral Gene ◽  
Blood Monocytes ◽  
Induced Differentiation ◽  
Organ Systems

Human cytomegalovirus (HCMV) infection of peripheral blood monocytes plays a key role in the hematogenous dissemination of the virus to multiple organ systems following primary infection or reactivation of latent virus in the bone marrow. Monocytes have a short life span of 1–3 days in circulation; thus, HCMV must alter their survival and differentiation to utilize these cells and their differentiated counterparts—macrophages—for dissemination and long term viral persistence. Because monocytes are not initially permissive for viral gene expression and replication, HCMV must control host-derived factors early during infection to prevent apoptosis or programmed cell death prior to viral induced differentiation into naturally long-lived macrophages. This review provides a short overview of HCMV infection of monocytes and describes how HCMV has evolved to utilize host cell anti-apoptotic pathways to allow infected monocytes to bridge the 48–72 h viability gate so that differentiation into a long term stable mature cell can occur. Because viral gene expression is delayed in monocytes following initial infection and only occurs (begins around two to three weeks post infection in our model) following what appears to be complete differentiation into mature macrophages or dendritic cells, or both; virally-encoded anti-apoptotic gene products cannot initially control long term infected cell survival. Anti-apoptotic viral genes are discussed in the second section of this review and we argue they would play an important role in long term macrophage or dendritic cell survival following infection-induced differentiation.

scholarly journals MicroRNA miR-21 Attenuates Human Cytomegalovirus Replication in Neural Cells by Targeting Cdc25a

2014 ◽  
Vol 89 (2) ◽  
pp. 1070-1082 ◽  
Author(s):  
Ya-Ru Fu ◽  
Xi-Juan Liu ◽  
Xiao-Jun Li ◽  
Zhang-zhou Shen ◽  
Bo Yang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Stem Cells ◽  
Birth Defects ◽  
Human Cytomegalovirus ◽  
Hcmv Infection ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Gene Products ◽  
Hcmv Replication

ABSTRACTCongenital human cytomegalovirus (HCMV) infection is a leading cause of birth defects, primarily manifesting as neurological disorders. HCMV infection alters expression of cellular microRNAs (miRs) and induces cell cycle arrest, which in turn modifies the cellular environment to favor virus replication. Previous observations found that HCMV infection reduces miR-21 expression in neural progenitor/stem cells (NPCs). Here, we show that infection of NPCs and U-251MG cells represses miR-21 while increasing the levels of Cdc25a, a cell cycle regulator and known target of miR-21. These opposing responses to infection prompted an investigation of the relationship between miR-21, Cdc25a, and viral replication. Overexpression of miR-21 in NPCs and U-251MG cells inhibited viral gene expression, genome replication, and production of infectious progeny, while shRNA-knockdown of miR-21 in U-251MG cells increased viral gene expression. In contrast, overexpression of Cdc25a in U-251MG cells increased viral gene expression and production of infectious progeny and overcame the inhibitory effects of miR-21 overexpression. Three viral gene products—IE1, pp71, and UL26—were shown to inhibit miR-21 expression at the transcriptional level. These results suggest that Cdc25a promotes HCMV replication and elevation of Cdc25a levels after HCMV infection are due in part to HCMV-mediated repression of miR-21. Thus, miR-21 is an intrinsic antiviral factor that is modulated by HCMV infection. This suggests a role for miR-21 downregulation in the neuropathogenesis of HCMV infection of the developing CNS.IMPORTANCEHuman cytomegalovirus (HCMV) is a ubiquitous pathogen and has very high prevalence among population, especially in China, and congenital HCMV infection is a major cause for birth defects. Elucidating virus-host interactions that govern HCMV replication in neuronal cells is critical to understanding the neuropathogenesis of birth defects resulting from congenital infection. In this study, we confirm that HCMV infection downregulates miR-21 but upregulates Cdc25a. Further determined the negative effects of cellular miRNA miR-21 on HCMV replication in neural progenitor/stem cells and U-251MG glioblastoma/astrocytoma cells. More importantly, our results provide the first evidence that miR-21 negatively regulates HCMV replication by targeting Cdc25a, a vital cell cycle regulator. We further found that viral gene products of IE1, pp71, and UL26 play roles in inhibiting miR-21 expression, which in turn causes increases in Cdc25a and benefits HCMV replication. Thus, miR-21 appears to be an intrinsic antiviral factor that represents a potential target for therapeutic intervention.

scholarly journals Effect of chronic JUUL aerosol inhalation on inflammatory states of the brain, lung, heart and colon in mice

2021 ◽  
Author(s):  
Alex Moshensky ◽  
Cameron Brand ◽  
Hasan Alhaddad ◽  
John Shin ◽  
Jorge A. Masso-Silva ◽  
...  
Keyword(s):  
Gene Expression ◽  
Inflammatory Responses ◽  
Multiple Organ ◽  
Cardiac Inflammation ◽  
Aerosol Inhalation ◽  
Organ Systems ◽  
Inflammatory State ◽  
Reward Pathways ◽  
Systemic Health

AbstractWhile health effects of conventional tobacco are well defined, data on vaping devices, including the most popular e-cigarette JUUL, are less established. Prior acute e-cigarette studies demonstrated inflammatory and cardiopulmonary physiology changes while chronic studies demonstrated extra-pulmonary effects, including neurotransmitter alterations in reward pathways. In this study we investigated effects of chronic flavored JUUL aerosol inhalation on inflammatory markers in brain, lung, heart, and colon. JUUL induced upregulation of cytokine and chemokine gene expression and increased HMGB1 and RAGE in the nucleus accumbens. Inflammatory gene expression increased in colon, and cardiopulmonary inflammatory responses to acute lung injury with lipopolysaccharide were exacerbated in the heart. Flavor-dependent changes in several responses were also observed. Our findings raise concerns regarding long-term risks of e-cigarette use as neuroinflammation may contribute to behavioral changes and mood disorders, while gut inflammation has been tied to poor systemic health and cardiac inflammation to development of heart disease.One Sentence SummaryChronic, daily inhalation of pod-based e-cigarette aerosols alters the inflammatory state across multiple organ systems in mice.

scholarly journals Extracellular Signal-Regulated Kinase Activity Is Sustained Early during Human Cytomegalovirus Infection

1998 ◽  
Vol 72 (11) ◽  
pp. 9173-9180 ◽  
Author(s):  
Steven M. Rodems ◽  
Deborah H. Spector
Keyword(s):  
Gene Expression ◽  
Signal Transduction ◽  
Transcription Factors ◽  
Protein Kinase ◽  
Hcmv Infection ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Extracellular Signal ◽  
Erk Activity ◽  
Cellular Transcription

ABSTRACT Expression of many early viral genes during human cytomegalovirus (HCMV) infection is dependent on cellular transcription factors. Several immediate-early and early viral promoters contain DNA binding sites for cellular factors such as CREB, AP-1, serum response factor, and Elk-1, and these transcription factors can be activated by phosphorylation via the cellular mitogen-activated protein kinase (MAPK) signal transduction cascade. To determine if the extracellular signal-regulated MAPKs, ERK1 and ERK2, play a role in transcription factor activation during infection, we tested for ERK activity during viral infection. We found that HCMV infection resulted in the maintenance of previously activated ERK1 and ERK2 by a mechanism which appears to involve the inhibition of a cellular phosphatase activity. ERK phosphorylation and activity were sustained for at least 8 h after infection, whereas in mock-infected cells, ERK activity steadily declined by 1 h postinfection. The activity of at least one cellular substrate of the ERKs, the protein kinase RSK1, was also maintained during this period. UV inactivation experiments suggested that viral gene expression was required for sustained ERK activity. In turn, activation of the ERKs appeared to be important for viral gene expression, as evidenced by the observed decrease in the transcriptional activity of the HCMV UL112-113 promoter during infection in the presence of the MEK inhibitor PD98059. These data suggest that HCMV utilizes cellular signal transduction pathways to activate viral or cellular transcription factors involved in the control of early viral gene expression and DNA replication.

scholarly journals PRMT5 Is Upregulated in HTLV-1-Mediated T-Cell Transformation and Selective Inhibition Alters Viral Gene Expression and Infected Cell Survival

Viruses ◽  
2015 ◽  
Vol 8 (1) ◽  
pp. 7 ◽  
Author(s):  
Amanda Panfil ◽  
Jacob Al-Saleem ◽  
Cory Howard ◽  
Jessica Mates ◽  
Jesse Kwiek ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Infected Cell ◽  
Cell Survival ◽  
Cell Transformation ◽  
Viral Gene Expression ◽  
Selective Inhibition ◽  
Viral Gene

scholarly journals Long-Term Infection and Shedding of Human Cytomegalovirus in T98G Glioblastoma Cells

2007 ◽  
Vol 81 (19) ◽  
pp. 10424-10436 ◽  
Author(s):  
Min Hua Luo ◽  
Elizabeth A. Fortunato
Keyword(s):  
Gene Expression ◽  
Cell Line ◽  
Human Cytomegalovirus ◽  
Neuroblastoma Cell ◽  
Viral Gene Expression ◽  
Early Gene ◽  
Viral Gene ◽  
Glioblastoma Cell ◽  
Virus Shedding

ABSTRACT Human cytomegalovirus (HCMV) is the leading viral cause of birth defects, affecting primarily the central nervous system (CNS). To further understand this CNS pathology, cells from glioblastoma cell lines T98G and A172, the astrocytic glioblastoma cell line CCF-STTG1 (CCF), and the neuroblastoma cell line SH-SY5Y (SY5Y) were infected with HCMV. CCF and SY5Y cells were fully permissive for infection, while A172 cells were nonpermissive. In T98G cells, the majority of cells showed viral deposition into the nucleus by 6 h postinfection (hpi); however, viral immediate-early gene expression was observed in only ∼30% of cells in the first 72 h. In viral antigen (Ag)-positive cells, although the development of complete viral replication centers was delayed, fully developed centers formed by 96 hpi. Interestingly, even at very late times postinfection, a mixture of multiple small, bipolar, and large foci was always present. The initial trafficking of input pp65 into the nucleus was also delayed. Titer and infectious-center assays showed a small number of T98G cells shedding virus at very low levels. Surprisingly, both Ag-positive and Ag-negative cells continued to divide; because of this continuous division, we adopted a protocol for passaging the T98G cells every third day to prevent overcrowding. Under this protocol, detectable infectious-virus shedding continued until passage 5 and viral gene expression continued through eight passages. This evidence points to T98G cells as a promising model for long-term infections.

scholarly journals Latency Reversing Agents: Kick and Kill of HTLV-1?

2021 ◽  
Vol 22 (11) ◽  
pp. 5545
Author(s):  
Annika P. Schnell ◽  
Stephan Kohrt ◽  
Andrea K. Thoma-Kress
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Viral Gene Expression ◽  
Cytotoxic T Cell ◽  
Viral Gene ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Cell Leukemia Virus Type ◽  
Reversing Agents ◽  
Ctl Responses

Human T-cell leukemia virus type 1 (HTLV-1), the cause of adult T-cell leukemia/lymphoma (ATLL), is a retrovirus, which integrates into the host genome and persistently infects CD4+ T-cells. Virus propagation is stimulated by (1) clonal expansion of infected cells and (2) de novo infection. Viral gene expression is induced by the transactivator protein Tax, which recruits host factors like positive transcription elongation factor b (P-TEFb) to the viral promoter. Since HTLV-1 gene expression is repressed in vivo by viral, cellular, and epigenetic mechanisms in late phases of infection, HTLV-1 avoids an efficient CD8+ cytotoxic T-cell (CTL) response directed against the immunodominant viral Tax antigen. Hence, therapeutic strategies using latency reversing agents (LRAs) sought to transiently activate viral gene expression and antigen presentation of Tax to enhance CTL responses towards HTLV-1, and thus, to expose the latent HTLV-1 reservoir to immune destruction. Here, we review strategies that aimed at enhancing Tax expression and Tax-specific CTL responses to interfere with HTLV-1 latency. Further, we provide an overview of LRAs including (1) histone deacetylase inhibitors (HDACi) and (2) activators of P-TEFb, that have mainly been studied in context of human immunodeficiency virus (HIV), but which may also be powerful in the context of HTLV-1.

scholarly journals The [KIL-d] Element Specifically Regulates Viral Gene Expression in Yeast

Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 601-609 ◽  
Author(s):  
Zsolt Tallóczy ◽  
Rebecca Mazar ◽  
Denise E Georgopoulos ◽  
Fausto Ramos ◽  
Michael J Leibowitz
Keyword(s):  
Gene Expression ◽  
Phenotypic Expression ◽  
Viral Gene Expression ◽  
Virus Genome ◽  
Viral Rna ◽  
High Rate ◽  
Viral Gene ◽  
Double Stranded Rna ◽  
Yeast Prions ◽  
Killer Virus

Abstract The cytoplasmically inherited [KIL-d] element epigenetically regulates killer virus gene expression in Saccharomyces cerevisiae. [KIL-d] results in variegated defects in expression of the M double-stranded RNA viral segment in haploid cells that are “healed” in diploids. We report that the [KIL-d] element is spontaneously lost with a frequency of 10−4–10−5 and reappears with variegated phenotypic expression with a frequency of ≥10−3. This high rate of loss and higher rate of reappearance is unlike any known nucleic acid replicon but resembles the behavior of yeast prions. However, [KIL-d] is distinct from the known yeast prions in its relative guanidinium hydrochloride incurability and independence of Hsp104 protein for its maintenance. Despite its transmissibility by successive cytoplasmic transfers, multiple cytoplasmic nucleic acids have been proven not to carry the [KIL-d] trait. [KIL-d] epigenetically regulates the expression of the M double-stranded RNA satellite virus genome, but fails to alter the expression of M cDNA. This specificity remained even after a cycle of mating and meiosis. Due to its unique genetic properties and viral RNA specificity, [KIL-d] represents a new type of genetic element that interacts with a viral RNA genome.

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