The IFITMs Inhibit Zika Virus Replication Savidis, George; Perreira, Jill M.; Portmann, Jocelyn M. ...
Cell reports,
06/2016, Letnik:
15, Številka:
11
Journal Article
Recenzirano
Odprti dostop
Zika virus has emerged as a severe health threat with a rapidly expanding range. The IFITM family of restriction factors inhibits the replication of a broad range of viruses, including the closely ...related flaviruses West Nile virus and dengue virus. Here, we show that IFITM1 and IFITM3 inhibit Zika virus infection early in the viral life cycle. Moreover, IFITM3 can prevent Zika-virus-induced cell death. These results suggest that strategies to boost the actions and/or levels of the IFITMs might be useful for inhibiting a broad range of emerging viruses.
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•IFITM3 and IFITM1 inhibit Zika virus infection•IFITM3 can prevent Zika-virus-induced cell death•The IFITMs can halt Zika virus early in the viral life cycle
Savidis et al. find that the IFITMs block Zika virus replication, including that of a recently isolated strain from Cambodia. Importantly, this protection translates into a large reduction in Zika-virus-induced cell death. The authors develop an imaging assay and determine that IFITM3 blocks the very earliest stages of Zika virus infection.
The flaviviruses dengue virus (DENV) and Zika virus (ZIKV) are severe health threats with rapidly expanding ranges. To identify the host cell dependencies of DENV and ZIKV, we completed orthologous ...functional genomic screens using RNAi and CRISPR/Cas9 approaches. The screens recovered the ZIKV entry factor AXL as well as multiple host factors involved in endocytosis (RAB5C and RABGEF), heparin sulfation (NDST1 and EXT1), and transmembrane protein processing and maturation, including the endoplasmic reticulum membrane complex (EMC). We find that both flaviviruses require the EMC for their early stages of infection. Together, these studies generate a high-confidence, systems-wide view of human-flavivirus interactions and provide insights into the role of the EMC in flavivirus replication.
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•RNAi and CRISPR/Cas9 screens were used to find flavivirus dependencies•The screens recovered host factors involved in endocytosis and heparin sulfation•The EMC is required by DENV and ZIKV in the early stages of replication•These studies give a systems-wide view of human-flavivirus interactions
Savidis et al. identify DENV and ZIKV dependencies using orthologous RNAi and CRISPR/Cas9 approaches. Multiple host factors involved in endocytosis and transmembrane protein processing, including the endoplasmic reticulum membrane complex (EMC), are important for flaviviral replication. Together, their studies generate a systems-wide view of human-flavivirus interactions.
Direct visualization of HIV-1 replication would improve our understanding of the viral life cycle. We adapted established technology and reagents to develop an imaging approach, ViewHIV, which ...allows evaluation of early HIV-1 replication intermediates, from reverse transcription to integration. These methods permit the simultaneous evaluation of both the capsid protein (CA) and viral DNA genome (vDNA) components of HIV-1 in both the cytosol and nuclei of single cells. ViewHIV is relatively rapid, uses readily available reagents in combination with standard confocal microscopy, and can be done with virtually any HIV-1 strain and permissive cell lines or primary cells. Using ViewHIV, we find that CA enters the nucleus and associates with vDNA in both transformed and primary cells. We also find that CA’s interaction with the host polyadenylation factor, CPSF6, enhances nuclear entry and potentiates HIV-1’s depth of nuclear invasion, potentially aiding the virus’s integration into gene-dense regions.
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•ViewHIV visualizes the HIV-1 capsid and viral DNA in the cytosol and nucleus•ViewHIV can be done with any HIV-1 strain and primary cells•ViewHIV shows that CA enters the nucleus and associates with vDNA•CA’s interaction with CPSF6 promotes HIV-1’s nuclear entry and integration
Chin et al. have developed an imaging assay, ViewHIV, which evaluates early HIV-1 replication intermediates. ViewHIV uses available reagents and works with primary cells. Using ViewHIV, they find that CA enters the nucleus and associates with vDNA. Furthermore, CA’s interaction with the host factor CPSF6 modulates HIV-1’s nuclear entry and integration.
Human rhinovirus (HRV) causes upper respiratory infections and asthma exacerbations. We screened multiple orthologous RNAi reagents and identified host proteins that modulate HRV replication. Here, ...we show that RNASEK, a transmembrane protein, was needed for the replication of HRV, influenza A virus, and dengue virus. RNASEK localizes to the cell surface and endosomal pathway and closely associates with the vacuolar ATPase (V-ATPase) proton pump. RNASEK is required for endocytosis, and its depletion produces enlarged clathrin-coated pits (CCPs) at the cell surface. These enlarged CCPs contain endocytic cargo and are bound by the scissioning GTPase, DNM2. Loss of RNASEK alters the localization of multiple V-ATPase subunits and lowers the levels of the ATP6AP1 subunit. Together, our results show that RNASEK closely associates with the V-ATPase and is required for its function; its loss prevents the early events of endocytosis and the replication of multiple pathogenic viruses.
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•Host proteins that modulate HRV replication were found by using MORR screens•RNASEK is needed for the replication of HRV, influenza A virus, and dengue virus•RNASEK localizes to the cell surface and endosomal pathway along with the V-ATPase•RNASEK is needed for endocytosis, and its loss produces enlarged clathrin-coated pits
Perreira et al. screened multiple orthologous RNAi reagents and identified host proteins that modulate human rhinovirus (HRV) replication. They found that RNASEK is needed for the replication of HRV, influenza A virus, and dengue virus, associates with the vacuolar ATPase (V-ATPase), and is required for endocytosis.
OBJECTIVES:Assess if amount of heat generated by postcardiac arrest patients to reach target temperature (Ttarget) during targeted temperature management is associated with outcomes by serving as a ...proxy for thermoregulatory ability, and whether it modifies the relationship between time to Ttarget and outcomes.
DESIGN:Retrospective cohort study.
SETTING:Urban tertiary-care hospital.
PATIENTS:Successfully resuscitated targeted temperature management–treated adult postarrest patients between 2008 and 2015 with serial temperature data and Ttarget less than or equal to 34°C.
INTERVENTIONS:None.
MEASUREMENTS AND MAIN RESULTS:Time to Ttarget was defined as time from targeted temperature management initiation to first recorded patient temperature less than or equal to 34°C. Patient heat generation (“heat units”) was calculated as inverse of average water temperature × hours between initiation and Ttarget × 100. Primary outcome was neurologic status measured by Cerebral Performance Category score; secondary outcome was survival, both at hospital discharge. Univariate analyses were performed using Wilcoxon rank-sum tests; multivariate analyses used logistic regression. Of 203 patients included, those with Cerebral Performance Category score 3–5 generated less heat before reaching Ttarget (median, 8.1 heat units interquartile range, 3.6–21.6 heat units vs median, 20.0 heat units interquartile range, 9.0–33.5 heat units; p = 0.001) and reached Ttarget quicker (median, 2.3 hr interquartile range, 1.5–4.0 hr vs median, 3.6 hr interquartile range, 2.0–5.0 hr; p = 0.01) than patients with Cerebral Performance Category score 1–2. Nonsurvivors generated less heat than survivors (median, 8.1 heat units interquartile range, 3.6–20.8 heat units vs median, 19.0 heat units interquartile range, 6.5–33.5 heat units; p = 0.001) and reached Ttarget quicker (median, 2.2 hr interquartile range, 1.5–3.8 hr vs median, 3.6 hr interquartile range, 2.0–5.0 hr; p = 0.01). Controlling for average water temperature between initiation and Ttarget, the relationship between outcomes and time to Ttarget was no longer significant. Controlling for location, witnessed arrest, age, initial rhythm, and neuromuscular blockade use, increased heat generation was associated with better neurologic (adjusted odds ratio, 1.01 95% CI, 1.00–1.03; p = 0.039) and survival (adjusted odds ratio, 1.01 95% CI, 1.00–1.03; p = 0.045) outcomes.
CONCLUSIONS:Increased heat generation during targeted temperature management initiation is associated with better outcomes at hospital discharge and may affect the relationship between time to Ttarget and outcomes.
Direct visualization of HIV-1 replication would improve our understanding of the viral lifecycle. We adapted established technology and reagents to develop an imaging approach, ViewHIV, which allows ...evaluation of early HIV-1 replication intermediates, from reverse transcription to integration. These methods permit the simultaneous evaluation of both the capsid protein (CA) and viral DNA genome (vDNA) components of HIV-1 in both the cytosol and nuclei of single cells. ViewHIV is relatively rapid, uses readily available reagents in combination with standard confocal microscopy, and can be done with virtually any HIV-1 strain and permissive cell lines or primary cells. Using ViewHIV, we find that CA enters the nucleus and associates with vDNA in both transformed and primary cells. We also find that CA’s interaction with the host polyadenylation factor, CPSF6, enhances nuclear entry and potentiates HIV-1’s depth of nuclear invasion, potentially aiding the virus’ integration into gene dense regions.
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