Biology subjects

Gray, K. M.

Publications and source records attributed to Gray, K. M..

3 recordsLinked to original sources

bioRxiv2021

Rhinovirus C replication is associated with the endoplasmic reticulum and triggers cytopathic effects in an in vitro model of human airway epithelium

The clinical impact of rhinovirus C (RV-C) is well-documented; yet the viral life cycle remains poorly defined. Thus, we characterized RV-C15 replication at the single-cell level and its impact on the human airway epithelium (HAE) using a physiologically-relevant in vitro model. RV-C15 replication was restricted to ciliated cells where viral RNA levels peaked at 12 hours post-infection (hpi), correlating with elevated titers in the apical compartment at 24 hpi. Notably, infection was associated with a loss of polarized expression of the RV-C receptor, cadherin-related family member 3. Visualization of double-stranded RNA (dsRNA) during RV-C15 replication revealed two distinct replication complex arrangements within the cell, likely corresponding to different time points in infection and correlating with the formation of large intracellular vesicles. To further define RV-C15 replication sites, we analyzed the expression of giantin, phosphatidylinositol-4- phosphate, and calnexin, as well as the colocalization of these markers with dsRNA. Fluorescence levels of all three cellular markers were elevated during infection and altered giantin distribution further indicated Golgi fragmentation. However, unlike previously characterized RVs, the high ratio of calnexin-dsRNA colocalization implicated the endoplasmic reticulum as the primary site for RV-C15 replication in HAE. RV-C15 infection was also associated with elevated stimulator of interferon genes (STING) expression, facilitating replication, and the induction of incomplete autophagy, a mechanism used by other RVs to promote non-lytic release of progeny virions. Finally, RV-C15 infection resulted in a temporary loss in epithelial barrier integrity and the translocation of tight junction proteins while a reduction in mucociliary clearance indicated cytopathic effects on epithelial function. Together, our findings identify both shared and unique features of RV-C replication compared to related rhinoviruses and define the impact of RV-C on both epithelial cell organization and tissue functionality - aspects of infection that may contribute to pathogenesis in vivo. Author summaryRhinovirus C has a global distribution and significant clinical impact - especially in those with underlying lung disease. Although RV-C is genetically, structurally, and biologically distinct from RV-A and -B viruses, our understanding of the RV-C life cycle has been largely inferred from these and other related viruses. Here, we performed a detailed analysis of RV-C15 replication in a physiologically-relevant model of human airway epithelium. Our single-cell, microscopy-based approach revealed that - unlike other RVs - the endoplasmic reticulum is the primary site for RV- C15 replication. RV-C15 replication also stimulated STING expression, which was proviral, and triggered dramatic changes in cellular organization, including altered virus receptor distribution, fragmented Golgi stacks, and the induction of incomplete autophagy. Additionally, we observed a loss of epithelial barrier function and a decrease in mucociliary clearance, a major defense mechanism in the lung, during RV-C15 infection. Together, these data reveal novel insight into RV-C15 replication dynamics and resulting cytopathic effects in the primary target cells for infection, thereby furthering our understanding of the pathogenesis of RV-C. Our work highlights similar, as well as unique, aspects of RV-C15 replication compared to related pathogens, which will help guide future studies on the molecular mechanisms of RV-C infection.

microbiology↗

bioRxiv2020

Neural vulnerability and hurricane-related media predict posttraumatic stress in youth

As natural disasters increase in frequency and severity1, 2, mounting evidence reveals that their human toll extends beyond death, injury, and loss. Posttraumatic stress (PTS) can be common among directly exposed individuals, and children are particularly vulnerable3, 4. Curiously, PTS can even be found among youth far removed from harms way, and media-based exposure may partially account for this phenomenon5-8. Unfortunately, susceptibility to media effects has been difficult to characterize because most research is initiated post-event, precluding examination of pre-disaster factors. In this study, we mitigate this issue with data from nearly 400 9-to 11-year-old children collected prior to and after Hurricane Irma. We evaluate whether preexisting neural patterns moderate associations between hurricane experiences and later Irma-related PTS. We show that "dose" of both objective exposure and Irma-related media exposure predicted Irma-related PTS, the latter even among children dwelling thousands of kilometers away from the hurricane. Furthermore, we show, using pre-hurricane functional magnetic resonance imaging data, that neural responses in brain regions associated with anxiety and stress confer particular vulnerability to the psychological effects of hurricane exposure among certain children. Surprisingly, this was even the case for media exposure- we found that that right amygdala reactivity to fearful stimuli moderated the association between Irma-related media exposure and PTS symptoms, with the media-PTS association strongest for children showing pre-hurricane heightened amygdala reactivity to Fear vs Neutral Faces. In contrast, in bilateral orbitofrontal cortex and left parahippocampal gyrus, children showing a weak response to the Fear condition relative to the Neutral condition were especially susceptible to PTS as a result of Irma-related media exposure. Collectively, these findings run counter to outdated "bullseye" models of disaster exposure that assume negative effects are narrowly circumscribed around a disasters geographic epicenter9. In contrast, for some youth with measurable preexisting vulnerability, consumption of extensive disaster-related media appears to offer an alternative pathway to disaster exposure that transcends geography and objective risk. This preventable exposure should be considered in disaster-related mental health efforts.

neuroscience↗

bioRxiv2018

Composition of the Survival Motor Neuron (SMN) complex in Drosophila melanogaster

Spinal Muscular Atrophy (SMA) is caused by homozygous mutations in the human survival motor neuron 1 (SMN1) gene. SMN protein has a well-characterized role in the biogenesis of small nuclear ribonucleoproteins (snRNPs), core components of the spliceosome. SMN is part of an oligomeric complex with core binding partners, collectively called Gemins. Biochemical and cell biological studies demonstrate that certain Gemins are required for proper snRNP assembly and transport. However, the precise functions of most Gemins are unknown. To gain a deeper understanding of the SMN complex in the context of metazoan evolution, we investigated the composition of the SMN complex in Drosophila melanogaster. Using a stable transgenic line that exclusively expresses Flag-tagged SMN from its native promoter, we previously found that Gemin2, Gemin3, Gemin5, and all nine classical Sm proteins, including Lsm10 and Lsm11, co-purify with SMN. Here, we show that CG2941 is also highly enriched in the pulldown. Reciprocal co-immunoprecipitation reveals that epitope-tagged CG2941 interacts with endogenous SMN in Schneider2 cells. Bioinformatic comparisons show that CG2941 shares sequence and structural similarity with metazoan Gemin4. Additional analysis shows that three other genes (CG14164, CG31950 and CG2371) are not orthologous to Gemins 6-7-8, respectively, as previously suggested. In D.melanogaster, CG2941 is located within an evolutionarily recent genomic triplication with two other nearly identical paralogous genes (CG32783 and CG32786). RNAi-mediated knockdown of CG2941 and its two close paralogs reveals that Gemin4 is essential for organismal viability.

genetics↗