Arbovirus interactions with arthropod hosts

Lead Research Organisation: MRC Virology Unit

Abstract

Arboviruses such as dengue or chikungunya are an important source of human disease worldwide. Arbovirus infection of insects such as mosquitoes that transmit these viruses is not a passive event but involves virus spreading through the mosquito, and insect defences trying to limit this spread. How these insect defences function is poorly understood, and the focus of our research.
We use model arboviruses to study antiviral mechanisms in mosquito cells and mosquitoes, but research on human pathogenic viruses such as dengue and chikungunya viruses is being established.
Mosquito antiviral control mechanisms can roughly be separated into those mediated by a process called RNA interference, or antimicrobial pathways usually associated with defence mechanisms against bacterial and fungal infections. We investigate how arbovirus infection initiates these mosquito defence mechanisms, how they are regulated, and how they exert their activity. In addition to studies

Technical Summary

Arthropod-borne viruses –arboviruses- of the Flaviviridae, Bunyaviridae and Togaviridae families continue to be an important source of human disease worldwide. Infection of insect vectors such as mosquitoes that transmit arboviruses such as dengue and chikungunya is not a passive event but involves virus replication and spread within the insect vector, and induction of immune responses by the vector to control virus replication and subsequently transmission. We have only recently begun to understand the nature of these antiviral immune responses; of key importance are small RNA-based pathways such as RNA interference (RNAi) but other immune responses do take place.
The main aim of this research programme is to further understand arthropod immune responses to arbovirus infection, in particular in the mosquito, and virus/host interactions. We use model alphaviruses such as Semliki Forest virus (SFV; for which we have a powerful reverse genetics system and an important number of molecular tools available) or replicons derived from alpha- and flaviviruses, but research on human pathogenic viruses such as dengue and chikungunya viruses is being established.

A particular focus of this programme is the RNAi response, and how it is induced and regulated in response to arbovirus infection. The classical RNAi response (also termed exogenous RNAi pathway) is based on degradation of viral double-stranded RNA (dsRNA) replication intermediates into 21 nucleotide siRNAs (also called virus-induced small interfering RNAs, or viRNAs) by a nuclease called Dcr-2; viRNA sequences can be determined by high-throughput sequencing. These viRNAs are integrated into a multiprotein complex called RISC, which uses the viRNAs as guide to find and degrade (through a nuclease called Ago-2) RNAs. Using established cell culture models (live mosquitoes are also available if required), we analyse the nature and properties of viRNAs and cellular small RNAs, as well as molecular mechanisms by which enzymes such as Dcr-2 target viral dsRNA, how this leads to degradation of viral RNAs by RISC, and how these processes are regulated. Other immune signalling pathways and processes (Jak/Stat, phenoloxidase cascade etc.) are also of interest to our research. For dengue virus, we moreover aim to look at all interactions of non-structural proteins with mosquito proteins by using high-throughput screening approaches. This will provide additional insights into virus/mosquito interactions.
We hope that this work will give us new clues as to how these virus/vector interactions function and how they determine transmission (ie. vector competence, the ability of a mosquito to transmit a given virus). With the advent of mosquito transgenesis, work on antiviral immunity and virus/host interactions may also suggest new targets in the vector that can be exploited.
In addition to the projects above, an ongoing project aims to better understand dengue virus transmission and epidemiology in parts of Java, Indonesia. This relates to frequency of transmission and disease, as well as climatic and geographical factors (including entomological studies), and typing of dengue viruses from mosquitoes and patient sera. This part of the programme will further our understanding of the factors involved with dengue transmission and help to inform public health policies in time.

Publications

10 25 50

publication icon
Carissimo G (2015) Antiviral immunity of Anopheles gambiae is highly compartmentalized, with distinct roles for RNA interference and gut microbiota. in Proceedings of the National Academy of Sciences of the United States of America

 
Description BBSRC Vector-Borne Diseases Expert Working Group
Geographic Reach National 
Policy Influence Type Participation in a advisory committee
 
Description Equipment Grant
Amount £55,000 (GBP)
Organisation Medical Research Council (MRC) 
Department Medical Research Foundation
Sector Charity/Non Profit
Country United Kingdom
Start  
 
Description International Postdoc (Internationell Postdok)
Amount 1,050,000 kr (SEK)
Organisation Swedish Research Council 
Sector Public
Country Switzerland
Start 03/2013 
End 02/2015
 
Title Schmallenberg virus reverse genetics system 
Description A reverse genetics system that allows to manipulate the Schmallenberg virus genome. This is based on cDNA clones for the three viral genome segments. 
Type Of Material Technology assay or reagent 
Year Produced 2013 
Provided To Others? Yes  
Impact This system can be used for vaccine development, development of viral vectors etc. 
URL http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1003133
 
Description Arthropod innate immune control of arbovirus replication 
Organisation Bernhard Nocht Institute for Tropical Medicine
Country Germany 
Sector Hospitals 
PI Contribution Arbovirus clones/infectious clones, assay systems, reagents; experimental design and and data interpretation.
Collaborator Contribution Arbovirus clones/infectious clones, assay systems, reagents; experimental design and data interpretation. With Professor Esther Schnettler.
Impact Novel data on arthropod antiviral immunity to arbovirus infection; publications listed with the relevant awards.
Start Year 2015
 
Description Biology of flavivirus sfRNA 
Organisation University of Wageningen
Country Netherlands 
Sector Academic/University 
PI Contribution Experimental assays and study design.
Collaborator Contribution Experimental assays and study design. With Dr G. Pijlman.
Impact Increased our undestanding of the properties flavivirus sfRNA; publications are listed with the relevant awards.
Start Year 2010
 
Description Bunyavirus-host interactions and replication 
Organisation University of Glasgow
Department MRC - University of Glasgow Centre for Virus Research
Country United Kingdom 
Sector Academic/University 
PI Contribution Arthropod innate immunity reagents and expertise; bunyavirus expertise and reagents including viruses and infectious clones; experimental design and data evaluation.
Collaborator Contribution Bunyavirus expertise and reagents including viruses, infectious clones, minireplicon systems, protein expression clones; experimental design and data evaluation. With Professor Richard M. Elliott until he passed away in 2015 and currently with Dr Benjamin Brennan.
Impact Publications as listed with the relevant awards; novel infectious clones and minireplicon systems for specific bunyaviruses and new functional data on bunyavirus proteins, bunyavirus replication, bunyavirus-host interactions including immunity.
Start Year 2013
 
Description Engineering of arboviruses for studies in arthropod infection assays 
Organisation The Pirbright Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution We collaborate on engineering alphavirus and bunyavirus genomes for studies in insect cells.
Collaborator Contribution Experimental assays.
Impact One paper published (PMID: 23559478).
Start Year 2011
 
Description ICRES Consortium 
Organisation University of Tartu
Country Estonia 
Sector Academic/University 
PI Contribution We joined this EU FP7-funded network on chikungunya virus research. Our contribution consisted of studies on chikungunya virus-insect cell interactions.
Collaborator Contribution We obtained reagents from collaborators.
Impact Key putput was the following paper: http://www.plosntds.org/article/info%3Adoi%2F10.1371%2Fjournal.pntd.0002994
Start Year 2011
 
Description Infectious clones of alphaviruses 
Organisation University of Tartu
Department Institute of Technology
PI Contribution Use of these viruses across host systems for replication/immunity/virus-host interaction assays. Contribution to design, cloning and production of alphavirus infectious clones and replicons; including mutant viruses, viruses expressing reporter and other genes/tags.
Collaborator Contribution Design, cloning and production of alphavirus infectious clones and replicons; viruses expressing reporter and other genes/tags.
Impact Publications are part of relevant awards and not individually listed here. This collaboratio has generated a large collection of alphavirus infectious clones and replicons.
Start Year 2006
 
Description Insect immune responses to Rift Valley fever virus 
Organisation Bernhard Nocht Institute for Tropical Medicine
Country Germany 
Sector Hospitals 
PI Contribution Innate immunity expertise; reagents; experimental design and data evaluation.
Collaborator Contribution Arthropod biology and innate immunity expertise; in vivo infection systems; experimental design and data evaluation. With Dr Stefanie Muller; initially BNITM then TiHO.
Impact Innate immunity data for Rift Valley fever virus infection across multiple insect systems. One publication resulted from this interaction: https://www.ncbi.nlm.nih.gov/pubmed/28497117
Start Year 2012
 
Description Insect immune responses to Rift Valley fever virus 
Organisation University of Veterinary Medicine Hanover
PI Contribution Innate immunity expertise; reagents; experimental design and data evaluation.
Collaborator Contribution Arthropod biology and innate immunity expertise; in vivo infection systems; experimental design and data evaluation. With Dr Stefanie Muller; initially BNITM then TiHO.
Impact Innate immunity data for Rift Valley fever virus infection across multiple insect systems. One publication resulted from this interaction: https://www.ncbi.nlm.nih.gov/pubmed/28497117
Start Year 2012
 
Description Mosquito bite site immunity 
Organisation University of Leeds
Country United Kingdom 
Sector Academic/University 
PI Contribution Experimental study systems including viruses; study design.
Collaborator Contribution Experimental study systems including immunology; study design. With Dr C. McKimmie, previously (at the start of the project) University of Glasgow and now University of Leeds.
Impact Novel data on how bite site host responses and mosquito saliva interact with arbovirus replication. One publication is listed with the relevant award.
Start Year 2013
 
Description Mosquito-arbovirus interactions 
Organisation Pasteur Institute, Paris
Country France 
Sector Academic/University 
PI Contribution Arboviruses and innate immunity expertise; experimental design and data evaluation.
Collaborator Contribution Mosquito infection systems; experimental design and data evaluation. With Dr Anna-Bella Failloux.
Impact Publications as listed with relevant awards; key interactions also within RiftVectors as well as Horizon 2020 Zikalliance and Infravec-2 consortia through taking lead of work packages and tasks given our combined expertise in the field at European level.
Start Year 2011
 
Description RiftVectors EMIDA-ERA NET consortium 
Organisation Experimental Zooprofilattico Institute of Lazio and Tuscany
Country Italy 
Sector Public 
PI Contribution Kohl leads the the RiftVectors consortium, which studies the vectors of Rift Valley fever. This includes partners in the UK, France and Italy. Subcontractors are located in Italy and Senegal. Associated partners of the RiftVectors consortium are based in Germany and the UK.
Collaborator Contribution We interact on several the work packages, and CVR/Kohl leads one of the work packages.
Impact Three original papers published: https://www.ncbi.nlm.nih.gov/pubmed/28497117 https://www.ncbi.nlm.nih.gov/pubmed/28060823 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4761212/
Start Year 2012
 
Description RiftVectors EMIDA-ERA NET consortium 
Organisation Lancaster University
Country United Kingdom 
Sector Academic/University 
PI Contribution Kohl leads the the RiftVectors consortium, which studies the vectors of Rift Valley fever. This includes partners in the UK, France and Italy. Subcontractors are located in Italy and Senegal. Associated partners of the RiftVectors consortium are based in Germany and the UK.
Collaborator Contribution We interact on several the work packages, and CVR/Kohl leads one of the work packages.
Impact Three original papers published: https://www.ncbi.nlm.nih.gov/pubmed/28497117 https://www.ncbi.nlm.nih.gov/pubmed/28060823 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4761212/
Start Year 2012
 
Description RiftVectors EMIDA-ERA NET consortium 
Organisation Pasteur Institute, Paris
Country France 
Sector Academic/University 
PI Contribution Kohl leads the the RiftVectors consortium, which studies the vectors of Rift Valley fever. This includes partners in the UK, France and Italy. Subcontractors are located in Italy and Senegal. Associated partners of the RiftVectors consortium are based in Germany and the UK.
Collaborator Contribution We interact on several the work packages, and CVR/Kohl leads one of the work packages.
Impact Three original papers published: https://www.ncbi.nlm.nih.gov/pubmed/28497117 https://www.ncbi.nlm.nih.gov/pubmed/28060823 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4761212/
Start Year 2012
 
Description Wolbachia Wellcome Trust Project Grant 
Organisation Gulbenkian Institute of Science
Country Portugal 
Sector Academic/University 
PI Contribution We are co-invstigators on a Wellcome Trust grant financing research at CVR, University of Cambridge and Gulbenkian Institute for Science.
Collaborator Contribution We have responsibility for one part of the research project. One post-doctoral fellow is employed on the grant.
Impact Key output of this project from the CVR side was a paper on Wolbachia-SFV interactions: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4835223/ One review article: https://www.ncbi.nlm.nih.gov/pubmed/24343914
Start Year 2011
 
Description Wolbachia Wellcome Trust Project Grant 
Organisation University of Cambridge
Country United Kingdom 
Sector Academic/University 
PI Contribution We are co-invstigators on a Wellcome Trust grant financing research at CVR, University of Cambridge and Gulbenkian Institute for Science.
Collaborator Contribution We have responsibility for one part of the research project. One post-doctoral fellow is employed on the grant.
Impact Key output of this project from the CVR side was a paper on Wolbachia-SFV interactions: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4835223/ One review article: https://www.ncbi.nlm.nih.gov/pubmed/24343914
Start Year 2011
 
Description miRNA targeted arboviruses for vaccine design 
Organisation The Pirbright Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution Design of miRNA containing Rift Valley fever and Semliki Forest viruses for mosquito infections.
Collaborator Contribution Production of miRNA target containing viruses, mosquito cell and mosquito infections. This collaboration began at the Roslin Institute, University of Edinburgh and continued at The Pirbright Institute with Professor John Fazakerley and Dr Rennos Fragkoudis though Ms Stacey Human's PhD thesis; Dr Fragkoudis currently continues the project.
Impact miRNA-targeted Semliki Forest viruses that showed differential replication in mosquito cells; miRNA-targeted Rift Valley fever viruses that remain to be fully characterised.
Start Year 2012
 
Title viRome Small RNA Analysis Software 
Description Software to analyse small RNAs 
Type Of Technology Webtool/Application 
Year Produced 2013 
Impact Not known in detail. 
URL http://www.ncbi.nlm.nih.gov/pubmed/23709497
 
Description CVR Facebook page 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact The CVR facebook page allows us to explain select, virology-related news as well as CVR activity to the public.

It is at present too early to assess the impact of this communication channel.
Year(s) Of Engagement Activity 2012
 
Description Print Media Engagment- Ebola Crisis- Kohl 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Interaction with press (several national daily newspapers); interpretation of information during the Ebola outbreak. The CVR keeps a record of these activities.

Increased public understanding of UK preparedness to Ebola and the biology of the disease. Impact is difficult to measure but newspapers with wide circulation and online presence reach a large audience.

I indicate one URL below; I was quoted elsewhere too and the CVR communications office have more on these activities.
Year(s) Of Engagement Activity 2014
 
Description Radio Interview- Kohl 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Type Of Presentation Keynote/Invited Speaker
Geographic Reach Regional
Primary Audience Media (as a channel to the public)
Results and Impact Response to media enquiry on a case of Crimean-Congo hemorrhagic fever virus infection imported into the Scotland.

Exposure of CVR activities and expertise to media and public.
Year(s) Of Engagement Activity 2012
 
Description TV Interviews (SKY, STV, BBC Scotland)- Kohl 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Media (as a channel to the public)
Results and Impact Response to media enquiry on a case of Crimean-Congo hemorrhagic fever virus infection imported into the Scotland. The CVR keeps a record of these activities.

Exposure of CVR activities and expertise to media and public.
Year(s) Of Engagement Activity 2012