Studentship: Autophagy and African swine fever virus

Lead Research Organisation: The Pirbright Institute
Department Name: UNLISTED

Abstract

Diseases of domestic livestock are an ever present threat to the challenge of feeding an increasing global population. African swine fever virus has existed in a natural cycle between warthogs and soft ticks for millennia, but causes a lethal, highly contagious, haemorrhagic fever in domestic swine and wild boar. In 2007, African swine fever was introduced into Georgia, probably through contaminated waste from a ship, and since has spread throughout most of European Russia and has now been reported in Poland, Lithuania, Latvia and Estonia. Effective vaccines against African swine fever are desperately needed.

Autophagy is a highly conserved intracellular pathway that has evolved to breakdown and recycle damaged cytoplasmic components by delivering them to lysosomes. Autophagy can also be induced in response to physiological stress, most notably that of starvation (The word autophagy literally means self-eat in Greek). Many important responses to infection are dependent on the autophagy pathway and pathogens have evolved mechanisms to manipulate autophagy for their own benefit. Recent experiments have demonstrated that disrupting the ability of viruses to inhibit autophagy can enhance immune responses. We have shown that African swine fever virus can block part of the autophagy pathway, raising the possibility that deletion of viral proteins that inhibit autophagy may enhance the immunogenicity of a live attenuated ASFV vaccine.

The major aims of this project are to further characterise the effect of African swine fever virus infection on the autophagy pathway, identify novel autophagy inhibitors in the African swine fever genome and generate recombinant viruses lacking these genes. The findings from these studies will contribute to the development of safe and effective, live attenuated ASFV vaccine candidates.

Publications

10 25 50
 
Description Viruses manipulate the host cell to both facilitate their own replication and avoid intrinsic, innate and adaptive immune responses. Autophagy is a cellular recycling pathway that is involved in many important functions including directing the immune response against, as well as directly degrading invading pathogens. We have shown that African swine fever virus blocks a critical step in the autophagy pathway and hypothesised that viruses that were unable to block autophagy may induce enhanced immune responses and represent potential vaccine candidates. We screened 70 out of the 128 core viral genes for autophagy modulators and found only one that could inhibit autophagy, whereas several were capable of inducing the pathway. We were able to identify a specific domain within the African swine fever autophagy inhibitor that was responsible for the phenomenon. However, a mutant virus lacking the identified autophagy inhibitor was still able to inhibit the pathway suggesting this gene was not necessary to inhibit the cellular process alone. The identification of a number of viral autophagy inducing proteins may explain why ASFV encodes for redundancy in its ability to block the pathway and strongly suggests that inhibition of autophagy is important for the virus.
We studied one of the genes that induced autophagy in greater detail and identified interacting partners my mass spectrometry, however no direct link with the pathway was observed. Detailed microscopy and biochemical analyses of the autophagy pathway suggested that the virus targets autophagy in at least two separate places which warrant further investigation. Remaining questions include, what mechanisms and genes does African swine fever virus use to manipulate the autophagy pathway and why? If we can identify these mechanisms can we manipulate them to improve African swine fever vaccine design?
An early career researcher has been trained in a number of specialised techniques with high consequence pathogens in containment laboratories, so enhancing the UKs science base
Exploitation Route The research increases our understanding of how viruses, and in particular African swine fever virus, manipulate their hosts. Newly identified interacting partners for individual viral proteins could be studied in greater detail to further our knowledge of virus-host interactions, likewise viral autophagy inducers may also contribute to how viruses interact with their host.
Sectors Agriculture, Food and Drink,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology

 
Title Autophagy inducer interactors 
Description A mass spectrometry data set of cellular proteins that interact with an African swine fever protein the induces autophagy. 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? No  
Impact None as yet 
 
Description Membrane protein interactions 
Organisation University of Liverpool
Department School of Veterinary Science Liverpool
Country United Kingdom 
Sector Academic/University 
PI Contribution Samples from cells transduced with ASFV membrane proteins have been prepared.
Collaborator Contribution Samples have been analysed for proteins interacting with ASFV membrane proteins by mass spectrometry.
Impact Collaboration still in progress
Start Year 2017
 
Description Structural analysis of ASFV-host protein interactions 
Organisation La Trobe University
Country Australia 
Sector Academic/University 
PI Contribution Mutations were introduced into ASFV autophagy modulators and the effects of these were tested in cell based microscopy assays.
Collaborator Contribution Structural analysis of virus-host interactions identified residues important for binding between virus and host proteins. These residues were the residues that chosen for mutation and subsequent analysis at Pirbright
Impact One peer-reviewed paper (https://www.ncbi.nlm.nih.gov/pubmed/31461953) This is multi-disciplinary. Pirbright has expertise in virology and cell based assays. La Trobe have expertise in structural biology.
Start Year 2017
 
Description Farnborough 6th Form College Careers Day 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Visited careers day at local 6th Form College to discuss a career in research and the work carried out at our institution
Year(s) Of Engagement Activity 2018
 
Description Pig and Poultry Fair 2019 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Discussed Institute research with pig and poultry farmers, related industry and the general public. Received requests for more information related to research, business and studentships.
Year(s) Of Engagement Activity 2018
URL https://www.pigandpoultry.org.uk/
 
Description Surrey Skills Fair 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Aimed at Year 9 students from Surrey Schools, promoting progression into further and higher education, training, employment and careers at a crucial time prior to choosing GCSE subject options. Aimed at Year 9s making their option choices, this skills and careers event is designed to help students understand the opportunities available to them post 16 and beyond. The 2014 event reached over 2000 students from 36 Surrey Schools, engaging with over 40 exhibitors.
Year(s) Of Engagement Activity 2015
 
Description Talk as part of the University of Veterinary Medicine (Vienna) doctoral school "Infectious Diseases of Pig and Poultry" 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Talked about the Pirbright Institute's work on African swine fever virus to researches in Veterinary Medicine (Virology and Immunology) in Vienna.
Year(s) Of Engagement Activity 2018