scholarly journals Genome-wide CRISPR activation screen identifies novel receptors for SARS-CoV-2 entry

2021 ◽  
Author(s):  
Shiyou Zhu ◽  
Ying Liu ◽  
Zhuo Zhou ◽  
Zhiying Zhang ◽  
Xia Xiao ◽  
...  

The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been endangering worldwide public health and economy. SARS-CoV-2 infects a variety of tissues where the known receptor ACE2 is low or almost absent, suggesting the existence of alternative pathways for virus entry. Here, we performed a genome-wide barcoded-CRISPRa screen to identify novel host factors that enable SARS-CoV-2 infection. In addition to known host proteins, i.e. ACE2, TMPRSS2, and NRP1, we identified multiple host components, among which LDLRAD3, TMEM30A, and CLEC4G were confirmed as functional receptors for SARS-CoV-2. All these membrane proteins bind directly to spike's N-terminal domain (NTD). Their essential and physiological roles have all been confirmed in either neuron or liver cells. In particular, LDLRAD3 and CLEC4G mediate SARS-CoV-2 entry and infection in a fashion independent of ACE2. The identification of the novel receptors and entry mechanisms could advance our understanding of the multiorgan tropism of SARS-CoV-2, and may shed light on the development of the therapeutic countermeasures against COVID-19.

2021 ◽  
Author(s):  
Annika Kratzel ◽  
Jenna N. Kelly ◽  
Yannick Brueggemann ◽  
Jasmine Portmann ◽  
Philip V’kovski ◽  
...  

SummaryOver the past 20 years, the emergence of three highly pathogenic coronaviruses (CoV) – SARS-CoV, MERS-CoV, and most recently SARS-CoV-2 – has shown that CoVs pose a serious risk to human health and highlighted the importance of developing effective therapies against them. Similar to other viruses, CoVs are dependent on host factors for their survival and replication. We hypothesized that evolutionarily distinct CoVs may exploit similar host factors and pathways to support their replication cycle. Here, we conducted two independent genome-wide CRISPR/Cas9 knockout screens to identify pan-CoV host factors required for the replication of both endemic and emerging CoVs, including the novel CoV SARS-CoV-2. Strikingly, we found that several autophagy-related genes, including the immunophilin FKBP8, TMEM41B, and MINAR1, were common host factors required for CoV replication. Importantly, inhibition of the immunophilin family with the compounds Tacrolimus, Cyclosporin A, and the non-immunosuppressive derivative Alisporivir, resulted in dose-dependent inhibition of CoV replication in primary human nasal epithelial cell cultures that resemble the natural site of virus replication. Overall, we identified host factors that are crucial for CoV replication and demonstrate that these factors constitute potential targets for therapeutic intervention by clinically approved drugs.


Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 68 ◽  
Author(s):  
Evgeniya Petrova ◽  
Ségolène Gracias ◽  
Guillaume Beauclair ◽  
Frédéric Tangy ◽  
Nolwenn Jouvenet

Flaviviruses, such as dengue (DENV), West Nile (WNV), yellow fever (YFV) and Zika (ZIKV) viruses, are mosquito-borne pathogens that present a major risk to global public health. To identify host factors that promote flavivirus replication, we performed a genome-wide gain-of-function cDNA screen for human genes that enhance the replication of flavivirus reporter particles in human cells. The screen recovered seventeen potential host proteins that promote viral replication, including the previously known dolichyl-diphosphooligosaccharide--protein glycosyltransferase non-catalytic subunit (DDOST). Using silencing approaches, we validated the role of four candidates in YFV and WNV replication: ribosomal protein L19 (RPL19), ribosomal protein S3 (RPS3), DDOST and importin 9 (IPO9). Applying a panel of virological, biochemical and microscopic methods, we validated further the role of RPL19 and DDOST as host factors required for optimal replication of YFV, WNV and ZIKV. The genome-wide gain-of-function screen is thus a valid approach to advance our understanding of flavivirus replication.


2018 ◽  
Author(s):  
Alain Casanova ◽  
Shyan Huey Low ◽  
Maxime Québatte ◽  
Jaroslaw Sedzicki ◽  
Therese Tschon ◽  
...  

AbstractBrucella,the causing agent of brucellosis, is a major zoonotic pathogen with worldwide distribution.Brucellaresides and replicates inside infected host cells in membrane-bound compartments called BCVs (Brucella-containing vacuoles). Following uptake,Brucellaresides in eBCVs (endosomal BCVs) that gradually mature from early to late endosomal features. Through a poorly understood process that is key to the intracellular lifestyle ofBrucella,the eBCV escapes fusion with lysosomes by transitioning to the rBCV (replicative BCV), a replicative niche directly connected to the endoplasmic reticulum (ER). Despite the notion that this complex intracellular lifestyle must depend on a multitude of host factors, a holistic view on which of these components controlBrucellacell entry, trafficking and replication is still missing. Here we used a systematic cell-based siRNA knockdown screen in HeLa cells infected withBrucella abortusand identified 425 components of the human infectome forBrucellainfection. These include multiple components of pathways involved in central processes such as cell cycle, actin cytoskeleton dynamics or vesicular trafficking. Using assays for pathogen entry, knockdown complementation and co-localization at single-cell resolution, we identified the requirement of the VPS retromer forBrucellato escape the lysosomal degradative pathway and to establish its intracellular replicative niche. We thus validated a component of the VPS retromer as novel host factor critical forBrucellaintracellular trafficking. Further, our genome-wide data shed light on the interplay between central host processes and the biogenesis of theBrucellareplicative niche.ImportanceWith >300,000 new cases of human brucellosis annually,Brucellais regarded as one of the most important zoonotic bacterial pathogen worldwide. The causing agent of brucellosis resides inside host cells within vacuoles termedBrucellacontaining vacuoles (BCVs). Although few host components required to escape the degradative lysosomal pathway and to establish the ER-derived replicative BCV (rBCV) have already been identified, the global understanding of this highly coordinated process is still partial and many factors remain unknown. To gain a deeper insight into these fundamental questions we performed a genome-wide RNA interference (RNAi) screen aiming at discovering novel host factors involved in theBrucellaintracellular cycle. We identified 425 host proteins that contribute toBrucellacellular entry, intracellular trafficking, and replication. Together, this study sheds light on previously unknown host pathways required for theBrucellainfection cycle and highlights the VPS retromer components as critical factors for the establishment of theBrucellaintracellular replicative niche.


Cell Reports ◽  
2021 ◽  
Vol 34 (11) ◽  
pp. 108859
Author(s):  
Jessie Kulsuptrakul ◽  
Ruofan Wang ◽  
Nathan L. Meyers ◽  
Melanie Ott ◽  
Andreas S. Puschnik

2021 ◽  
Vol 12 ◽  
Author(s):  
Tong Li ◽  
Ruobing Guan ◽  
Yuqing Wu ◽  
Su Chen ◽  
Guohui Yuan ◽  
...  

In the present study, we identified a novel, positive-sense single-stranded RNA virus in the Chinese black cutworm, Agrotis ipsilon. It has a genome length of 11,312 nucleotides, excluding the poly(A) tails, and contains five open reading frames. The ORF2 encodes the conserved domains of RNA helicase and RNA-dependent RNA polymerase, while ORF4 and 5 encode three viral proteins. Herein, the A. ipsilon virus was clustered with a Helicoverpa armigera Nora virus and was thus provisionally named “Agrotis ipsilon Nora virus” (AINV). AINV was successfully transmitted into a novel host, Spodoptera frugiperda, through injection, causing a stable infection. This found the possibility of horizontal AINV transmission among moths belonging to the same taxonomic family. Nonetheless, AINV infection was deleterious to S. frugiperda and mainly mediated by antiviral and amino acid metabolism-related pathways. Furthermore, the infection significantly increased the S. frugiperda larval period but significantly reduced its moth eclosion rate. It suggests that AINV is probably to be a parasitic virus of S. frugiperda.


mBio ◽  
2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Michael G. Connor ◽  
Amanda R. Pulsifer ◽  
Donghoon Chung ◽  
Eric C. Rouchka ◽  
Brian K. Ceresa ◽  
...  

ABSTRACTYersinia pestishas evolved many strategies to evade the innate immune system. One of these strategies is the ability to survive within macrophages. Upon phagocytosis,Y. pestisprevents phagolysosome maturation and establishes a modified compartment termed theYersinia-containing vacuole (YCV).Y. pestisactively inhibits the acidification of this compartment, and eventually, the YCV transitions from a tight-fitting vacuole into a spacious replicative vacuole. The mechanisms to generate the YCV have not been defined. However, we hypothesized that YCV biogenesis requiresY. pestisinteractions with specific host factors to subvert normal vesicular trafficking. In order to identify these factors, we performed a genome-wide RNA interference (RNAi) screen to identify host factors required forY. pestissurvival in macrophages. This screen revealed that 71 host proteins are required for intracellular survival ofY. pestis. Of particular interest was the enrichment for genes involved in endosome recycling. Moreover, we demonstrated thatY. pestisactively recruits Rab4a and Rab11b to the YCV in a type three secretion system-independent manner, indicating remodeling of the YCV byY. pestisto resemble a recycling endosome. While recruitment of Rab4a was necessary to inhibit YCV acidification and lysosomal fusion early during infection, Rab11b appeared to contribute to later stages of YCV biogenesis. We also discovered thatY. pestisdisrupts global host endocytic recycling in macrophages, possibly through sequestration of Rab11b, and this process is required for bacterial replication. These data provide the first evidence thatY. pestistargets the host endocytic recycling pathway to avoid phagolysosomal maturation and generate the YCV.IMPORTANCEYersinia pestiscan infect and survive within macrophages. However, the mechanisms that the bacterium use to subvert killing by these phagocytes have not been defined. To provide a better understanding of these mechanisms, we used an RNAi approach to identify host factors required for intracellularY. pestissurvival. This approach revealed that the host endocytic recycling pathway is essential forY. pestisto avoid clearance by the macrophage. We further demonstrate thatY. pestisremodels the phagosome to resemble a recycling endosome, allowing the bacterium to avoid the normal phagolysosomal maturation pathway. Moreover, we show that infection withY. pestisdisrupts normal recycling in the macrophage and that disruption is required for bacterial replication. These findings provide the first evidence thatY. pestistargets the host endocytic recycling pathway in order to evade killing by macrophages.


Proceedings ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 149
Author(s):  
Anna Dukhovny ◽  
Kevin Lamkiewicz ◽  
Qian Chen ◽  
Markus Fricke ◽  
Nabila Jabrane-Ferrat ◽  
...  

Zika virus (ZIKV) is an arthropod-borne emerging pathogen causing febrile illness. ZIKV is associated with the Guillain–Barré syndrome and other neurological complications. The vertical transmission of ZIKV can cause fetus demise, stillbirths or severe congenital abnormalities and neurological complications. There is still no vaccine or specific treatment for ZIKV infection. To identify the host factors that can rescue cells from ZIKV infection, we used a genome-scale CRISPR activation screen. Our highly ranking hits included a short list of interferon-stimulated genes (ISGs) previously reported to have antiviral activity. Validation of the screen results highlighted interferon lambda 2 (IFN-lamda2) and interferon alpha-inducible protein 6 (IFI6) as genes providing high levels of protection from ZIKV infection. The activation of these genes had an effect at an early stage in the viral infection. In addition, infected cells expressing single guide RNAs (sgRNAs) for both of these genes displayed lower levels of cell death than did the controls. Furthermore, the identified genes were significantly induced in ZIKV-infected placenta explants. These results highlighted a set of ISGs directly relevant for rescuing cells from ZIKV infection or its associated cell death, thus substantiating CRISPR activation screens as a valid tool for identifying host factors impeding pathogen infection.


PLoS Biology ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. e3001490
Author(s):  
Annika Kratzel ◽  
Jenna N. Kelly ◽  
Philip V’kovski ◽  
Jasmine Portmann ◽  
Yannick Brüggemann ◽  
...  

Over the past 20 years, 3 highly pathogenic human coronaviruses (HCoVs) have emerged—Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and, most recently, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)—demonstrating that coronaviruses (CoVs) pose a serious threat to human health and highlighting the importance of developing effective therapies against them. Similar to other viruses, CoVs are dependent on host factors for their survival and replication. We hypothesized that evolutionarily distinct CoVs may exploit similar host factors and pathways to support their replication cycles. Herein, we conducted 2 independent genome-wide CRISPR/Cas-9 knockout (KO) screens to identify MERS-CoV and HCoV-229E host dependency factors (HDFs) required for HCoV replication in the human Huh7 cell line. Top scoring genes were further validated and assessed in the context of MERS-CoV and HCoV-229E infection as well as SARS-CoV and SARS-CoV-2 infection. Strikingly, we found that several autophagy-related genes, including TMEM41B, MINAR1, and the immunophilin FKBP8, were common host factors required for pan-CoV replication. Importantly, inhibition of the immunophilin protein family with the compounds cyclosporine A, and the nonimmunosuppressive derivative alisporivir, resulted in dose-dependent inhibition of CoV replication in primary human nasal epithelial cell cultures, which recapitulate the natural site of virus replication. Overall, we identified host factors that are crucial for CoV replication and demonstrated that these factors constitute potential targets for therapeutic intervention by clinically approved drugs.


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