Biology subjects

Ileana M Cristea, I. M.

Publications and source records attributed to Ileana M Cristea, I. M..

3 recordsLinked to original sources

bioRxiv2024

ARPE-19 Epithelial Cells Fail To Initiate Type-I Interferon Signaling in Response to Human Cytomegalovirus Infection.

ARPE-19 cells are a commonly used epithelial model for studying human cytomegalovirus (HCMV) infection. We recently found that ARPE-19 cells assume a mesenchymal phenotype when maintained at low confluency and that ARPE-19 cells resemble mesenchymal fibroblasts rather than epithelial cells in HCMV infection assays. Here, using comparative proteomics analysis, we find that subconfluent ARPE-19 cells are also deficient in their ability to initiate canonical type-I interferon signaling. Comparative proteomic analysis between subconfluent ARPE-19 and MRC-5 cells revealed a lack of canonical type-I interferon response in ARPE-19 cells upon HCMV infection, evidenced by the absence of interferon stimulated gene (ISG) induction. qRT-PCR and RNA-sequencing analysis revealed that ARPE-19 cells fail to initiate interferon-beta transcription in response to HCMV infection, yet they are competent to respond to exogenously interferon-b, indicating a failure in early pathogen detection. ARPE-19 cells showed low baseline levels of key intracellular pattern recognition receptors (PRRs) such as CGAS and IFI16, as well as the signaling molecule STING. This deficiency was associated with a failure to activate IRF3 phosphorylation, a crucial step in interferon signaling. These findings suggest an upstream defect in the early detection of viral components, likely due to reduced expression of critical PRRs. ARPE-19 cells may be inherently deficient in initiating interferon responses due to their derivation or possibly due to their origin from an immune-privileged tissue. Our results continue to highlight important phenotypic characteristics of the ARPE-19 cell line; important considerations for those using ARPE-19 cells as an experimental infection model for studying HCMV or other human viruses.

microbiology↗

bioRxiv2020

Cardiac Sex Differences are Established Prior to Gonad Formation

Male and female disease states differ in their prevalence, treatment responses, and survival rates. In cardiac disease, women almost uniformly fare far worse than men. Though sex plays a critical role in cardiac disease, the mechanisms underlying sex differences in cardiac homeostasis and disease remain unexplained. Here, in adult and embryonic hearts we reveal sex-specific transcriptomes and proteomes and show that cardiac sex differences are predominately accounted for by post-transcriptional mechanisms. We found differential expression of male-female proteins in the cardiomyocytes. Using a quantitative proteomics-based approach, we characterized differential sex-specific enriched cardiac proteins, protein complexes, and biological sex processes in the context of global genetic diversity of the Collaborative Cross, an established surrogate for human diversity. We also found that sex differences in cardiac protein expression are established by both hormonal and sex chromosomal mechanisms. We have demonstrated the onset of sex-biased protein expression and discovered that sex disparities in heart tissue occur at the earliest stages of heart development at a period that preceeds mammalian gonadal development. Collectively, these findings may explain why congenital heart disease, a leading cause of death whose origin is often developmental, is sex biased. Our results reveal molecular foundations for differences in cardiac tissue that underlie sex disparities in health, disease, and treatment outcomes.

developmental biology↗

bioRxiv2020

The axonal sorting activity of pseudorabies virus Us9 protein depends on the state of neuronal maturation

Alpha-herpesviruses establish a life-long infection in the nervous system of the affected host; while this infection is restricted to peripheral neurons in a healthy host, the reactivated virus can spread within the neuronal circuitry, such as to the brain, in compromised individuals and lead to adverse health outcomes. Pseudorabies virus (PRV), an alpha-herpesvirus, requires the viral protein Us9 to sort virus particles into axons and facilitate neuronal spread. Us9 sorts virus particles by mediating the interaction of virus particles with neuronal transport machinery. Here, we report that Us9-mediated regulation of axonal sorting also depends on the state of neuronal maturation. Specifically, the development of dendrites and axons is accompanied with proteomic changes that influence neuronal processes. Immature superior cervical ganglionic neurons (SCGs) have rudimentary neurites that lack markers of mature axons. Immature SCGs can be infected by PRV, but they show markedly reduced Us9-dependent regulation of sorting, and increased Us9-independent transport of particles into neurites. Mature SCGs have relatively higher abundances of proteins characteristic of vesicle-transport machinery. We also identify Us9-associated neuronal proteins that can contribute to axonal sorting and subsequent anterograde spread of virus particles in axons. We show that SMPD4/nsMase3, a sphingomyelinase abundant in lipid-rafts, associates with Us9 and is a negative regulator of PRV sorting into axons and neuronal spread, a potential antiviral function. Author SummaryViral pathogenesis often is age-dependent, with more severe outcomes for infected fetuses and neonates compared to adults. As neurons age and mature, dendrites and axons polarize with distinct functions that affect neurotropic virus replication and neuronal spread of infection. This study investigates how neuronal maturation of peripheral nervous system neurons, the site of alpha-herpesvirus life-long latency and reactivation, affects replication and neuronal spread of pseudorabies virus. Characterization of infected immature and mature primary cultures of superior cervical ganglionic neurons revealed significant differences in protein composition and cellular processes that affected the activity of Us9, a viral protein required for sorting virus particles into axons. We identified neuronal and viral proteins that interact with Us9 in immature and mature neurons. Among these, we demonstrate that SMPD4/nsMase3, a sphingomyelinase critical for membrane organization and neuronal function, regulates PRV neuronal spread by preventing capsid association with Us9-containing membranes, presenting a possible antiviral function.

molecular biology↗