The role of natural killer cells in host defence against varicella

Lead Research Organisation: Newcastle University
Department Name: Institute of Cellular Medicine

Abstract

We know that the lymphocytes of our immune system are very important for control of the virus that causes chickenpox and shingles, VZV. When immunity is suppressed, for instance by cancer chemotherapy, chickenpox may be a very severe illness. Occasionally, previously healthy children become similarly unwell, prompting us to ask if their immune system is faulty. Often, none of the known causes of inherited immunodeficiency can be found, but in rare cases there is a shortage of natural killer (NK) lymphocytes. This may be giving us a clue about how VZV is contained by the normal immune system.

In the first part of this project we will investigate whether and how NK cells could contribute to the control of VZV in normal individuals. We will then study antiviral immune responses in children who have suffered unusually severe chickenpox. If we are right that NK cells help to control VZV, we predict that some of these children will have inherited problems with NK function. We will try to identify which specific genes are faulty. Improved understanding of the way the immune system interacts with viruses like VZV will help us to look after a broader group of affected children and adults.

Technical Summary

Understanding the concerted host immune response to varicella zoster virus (VZV) remains an important goal. Despite the availability of effective antiviral chemotherapy and a live attenuated vaccine against VZV, deaths and morbidity due to severe varicella continue to occur. Much of this burden is borne by previously healthy children who have no evidence of a general impairment of cellular immunity. Among this group, however, the presence of rare individuals with an absolute deficiency of natural killer (NK) cells points to a key role for this lymphocyte subset in protection against VZV.

The overall aim of this project is to discover how NK cells participate in host defence against VZV. Specifically, I will test the ability of NK cells to recognize VZV-infected targets and the outcome of their encounter. I will ascertain what molecular interactions mediate NK recognition of VZV-infected cells. Finally, I will test the hypothesis that inherited defects of NK function produce heightened susceptibility to varicella.

NK activity against VZV-infected cells will be studied in vitro using well-established techniques with which I am familiar. I will examine the ability of VZV-infected fibroblasts to elicit cytotoxicity and cytokine release by NK cell lines derived from healthy adult peripheral blood. I will probe the molecular basis of target recognition, by investigating the effect of blocking specific NK activating receptors. This will be complemented by an analysis of how VZV modulates the expression of putative NK ligands. Key findings will be confirmed in an autologous system. An important goal will be to extend these analyses to VZV-infected dendritic cells and thereby explore potential immunomodulatory outcomes of their interaction with NK cells.

Insights obtained in the first half of the fellowship will be related to real patients in the second, when I will study children who have suffered severe varicella. I will apply a panel of flow cytometric and functional assays of NK cells alongside measures of adaptive immunity to VZV. To further assist in the identification of potential disease-causing genes, the transcriptional profile of NK cells from patients and controls will be compared using microarray analysis. Candidate genes will be sequenced to identify disease-causing mutations. Exploration of their effects at cellular and molecular levels will form the basis of further experimental study.

These important investigations promise to shed light on early events in the pathogenesis of severe varicella, and may identify new targets for immunomodulatory therapy for this devastating illness.

Publications

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Bate J (2011) PEPtalk: postexposure prophylaxis against varicella in children with cancer. in Archives of disease in childhood

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Bigley V (2011) The human syndrome of dendritic cell, monocyte, B and NK lymphoid deficiency. in The Journal of experimental medicine

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Bolze A (2010) Whole-exome-sequencing-based discovery of human FADD deficiency. in American journal of human genetics

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Collin M (2011) Human dendritic cell deficiency: the missing ID? in Nature reviews. Immunology

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Fisher JP (2011) Preventing varicella in children with malignancies: what is the evidence? in Current opinion in infectious diseases

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Hambleton S (2011) Editorial commentary: a better grip: T cells strengthen our hand against influenza. in Clinical infectious diseases : an official publication of the Infectious Diseases Society of America

 
Description ALPS - Freiburg 
Organisation Albert Ludwigs University of Freiburg
Department Centre of Chronic Immunodeficiency
Country Germany 
Sector Academic/University 
PI Contribution Contributing patient material and information to the ALPS registry, on which their research is based. We are also now collaborating on a pan-European longitudinal study of profound combined immunodeficiency. We have identified a novel genetic cause of ALPS0 in 2 brothers from a consanguineous family
Collaborator Contribution Sharing of laboratory protocols, advice and experience (including a physical visit to their lab)
Impact Recent papers (1st author Rensing-Ehl)
Start Year 2009
 
Description Autozygosity mapping 
Organisation University of Birmingham
Department College of Life and Environmental Sciences
Country United Kingdom 
Sector Academic/University 
PI Contribution I have recognised novel immunodeficiency phenotypes at clinical level, designed and carried out experiments to characterise cellular defects in vitro and contributed to writing up the work. I have set up a biobank to manage material from individuals with suspected inborn errors, their family members and healthy controls. In collaboration with colleagues at Newcastle University, we are undertaking exome sequencing in a number of kindreds in whom autozygosity mapping by the Birmingham group has already defined a narrow candidate region for novel genetic defects.
Collaborator Contribution I have collaborated with Professor Eamonn Maher and Dr Neil Morgan on the genetic characterisation of primary immunodeficiency arising within consanguineous kindreds. Their expertise in autozygosity mapping has led directly to the discovery of novel genetic disorders.
Impact Bolze et al (2010) Morgan et al (2011) Hambleton et al (2013) Lu et al (2014) Dang et al (2016)
Start Year 2009
 
Description DC deficiency 
Organisation McGill University
Department Department of Biochemistry
Country Canada 
Sector Academic/University 
PI Contribution Ideas, patients, strategy, experiments, analysis, writing
Collaborator Contribution Detailed evaluation of DC/monocyte compartment, immunocytochemistry & histopathologySequencing of IRF8 and in vitro validation of the functional effects of mutationFurther patients identified and characterised using similar methods
Impact Hambleton et al (2011) Bigley et al (2011) Dickinson et al (2011) Collin et al (2011) Dickinson et al (2014) Salem et al (2015) and ongoing work Clinicians and basic scientists
Start Year 2009
 
Description DC deficiency 
Organisation Newcastle University
Department Institute of Cellular Medicine
Country United Kingdom 
Sector Academic/University 
PI Contribution Ideas, patients, strategy, experiments, analysis, writing
Collaborator Contribution Detailed evaluation of DC/monocyte compartment, immunocytochemistry & histopathologySequencing of IRF8 and in vitro validation of the functional effects of mutationFurther patients identified and characterised using similar methods
Impact Hambleton et al (2011) Bigley et al (2011) Dickinson et al (2011) Collin et al (2011) Dickinson et al (2014) Salem et al (2015) and ongoing work Clinicians and basic scientists
Start Year 2009
 
Description DC deficiency 
Organisation Rockefeller University
Department St Giles Laboratory of Human Genetics of Infectious Disease
Country United States 
Sector Academic/University 
PI Contribution Ideas, patients, strategy, experiments, analysis, writing
Collaborator Contribution Detailed evaluation of DC/monocyte compartment, immunocytochemistry & histopathologySequencing of IRF8 and in vitro validation of the functional effects of mutationFurther patients identified and characterised using similar methods
Impact Hambleton et al (2011) Bigley et al (2011) Dickinson et al (2011) Collin et al (2011) Dickinson et al (2014) Salem et al (2015) and ongoing work Clinicians and basic scientists
Start Year 2009
 
Description IPEX Hilkens 
Organisation Newcastle University
Department Institute of Cellular Medicine
Country United Kingdom 
Sector Academic/University 
PI Contribution I realised that human FoxP3 deficiency, which causes IPEX syndrome, would provide a good model system in which to address specific hypotheses arising from Dr Hilkens' group's previous work. I was able to source biological material from such a patient which enabled this experiment to be performed, thus refuting the hypothesis that FoxP3 activity is necessary for the suppression of Th17 differentiation at high levels of TCR stimulation.
Collaborator Contribution Mutual consultative support in the context of regular laboratory meetings
Impact Recent paper in Blood (Purvis et al)
Start Year 2009
 
Description Innate antiviral immunity 
Organisation University of St Andrews
Department School of Biology
Country United Kingdom 
Sector Academic/University 
PI Contribution Initiated collaboration in order to explore an unusual viral susceptibility phenotype
Collaborator Contribution Assays of viral susceptibility, interferon production and signaling
Impact Hambleton et al (2013) Proc Natl Acad Sci USA Duncan et al (2015) Sci Transl Med Collaboration involves virologists and immunologists
Start Year 2011
 
Description Newcastle Exome Consortium 
Organisation Newcastle University
Department Institute of Genetic Medicine
Country United Kingdom 
Sector Academic/University 
PI Contribution We provided ideas & patient material and assisted with analysis and validation of variants found.
Collaborator Contribution Together, we set up a consortium to facilitate exome sequencing on the Illumina sequencer already acquired by the University. The consortium includes geneticists, bioinformaticians, biologists and clinicians.
Impact Dickinson et al (2011) Horvath et al (2012) Dickinson et al (2014) Lu et al (2014) Dang et al (2016) Multidisciplinary: paediatric immunology, basic science, bioinformatics, clinical genetics
Start Year 2010
 
Description PEPtalk 
Organisation Children's Cancer and Leukaemia Group (CCLG)
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution I initiated this collaboration by gathering together interested parties to consider the issue of post-exposure prophylaxis against varicella in children being treated for cancer. I assembled the team and led a feasibility study, gathering and analysing most of the data.
Collaborator Contribution Contributed epidemiologic knowledge and clinical trials know-how Paediatric Infectious Disease knowledge & expertise Specific virology expertise Epidemiologic data and expertise Detailed knowledge & expertise in paediatric oncology, access to paediatric oncologists' mailing list, general support
Impact Bate et al (2011, 2012), Fisher et al (2011). We obtained funding from NIHR (RfPB stream) for a pilot trial on which I was a coapplicant (CI Paul Heath at SGUL). It proved extremely difficult to recruit to the study which therefore had the effect of showing that a full trial would not be possible. This was a multidisciplinary collaboration: paediatric immunology, infectious diseases, virology, paediatric oncology, medical statistics, health economics, epidemiology
Start Year 2009
 
Description PEPtalk 
Organisation Public Health England
Department Centre of Infectious Disease Surveillance and Control
Country United Kingdom 
Sector Public 
PI Contribution I initiated this collaboration by gathering together interested parties to consider the issue of post-exposure prophylaxis against varicella in children being treated for cancer. I assembled the team and led a feasibility study, gathering and analysing most of the data.
Collaborator Contribution Contributed epidemiologic knowledge and clinical trials know-how Paediatric Infectious Disease knowledge & expertise Specific virology expertise Epidemiologic data and expertise Detailed knowledge & expertise in paediatric oncology, access to paediatric oncologists' mailing list, general support
Impact Bate et al (2011, 2012), Fisher et al (2011). We obtained funding from NIHR (RfPB stream) for a pilot trial on which I was a coapplicant (CI Paul Heath at SGUL). It proved extremely difficult to recruit to the study which therefore had the effect of showing that a full trial would not be possible. This was a multidisciplinary collaboration: paediatric immunology, infectious diseases, virology, paediatric oncology, medical statistics, health economics, epidemiology
Start Year 2009
 
Description PEPtalk 
Organisation St George's University of London
Department Division of Child Health
Country United Kingdom 
Sector Academic/University 
PI Contribution I initiated this collaboration by gathering together interested parties to consider the issue of post-exposure prophylaxis against varicella in children being treated for cancer. I assembled the team and led a feasibility study, gathering and analysing most of the data.
Collaborator Contribution Contributed epidemiologic knowledge and clinical trials know-how Paediatric Infectious Disease knowledge & expertise Specific virology expertise Epidemiologic data and expertise Detailed knowledge & expertise in paediatric oncology, access to paediatric oncologists' mailing list, general support
Impact Bate et al (2011, 2012), Fisher et al (2011). We obtained funding from NIHR (RfPB stream) for a pilot trial on which I was a coapplicant (CI Paul Heath at SGUL). It proved extremely difficult to recruit to the study which therefore had the effect of showing that a full trial would not be possible. This was a multidisciplinary collaboration: paediatric immunology, infectious diseases, virology, paediatric oncology, medical statistics, health economics, epidemiology
Start Year 2009
 
Description PEPtalk 
Organisation University College London
Department MRC Centre for Medical Molecular Virology
Country United Kingdom 
Sector Public 
PI Contribution I initiated this collaboration by gathering together interested parties to consider the issue of post-exposure prophylaxis against varicella in children being treated for cancer. I assembled the team and led a feasibility study, gathering and analysing most of the data.
Collaborator Contribution Contributed epidemiologic knowledge and clinical trials know-how Paediatric Infectious Disease knowledge & expertise Specific virology expertise Epidemiologic data and expertise Detailed knowledge & expertise in paediatric oncology, access to paediatric oncologists' mailing list, general support
Impact Bate et al (2011, 2012), Fisher et al (2011). We obtained funding from NIHR (RfPB stream) for a pilot trial on which I was a coapplicant (CI Paul Heath at SGUL). It proved extremely difficult to recruit to the study which therefore had the effect of showing that a full trial would not be possible. This was a multidisciplinary collaboration: paediatric immunology, infectious diseases, virology, paediatric oncology, medical statistics, health economics, epidemiology
Start Year 2009
 
Description PEPtalk 
Organisation University of Birmingham
Department College of Life and Environmental Sciences
Country United Kingdom 
Sector Academic/University 
PI Contribution I initiated this collaboration by gathering together interested parties to consider the issue of post-exposure prophylaxis against varicella in children being treated for cancer. I assembled the team and led a feasibility study, gathering and analysing most of the data.
Collaborator Contribution Contributed epidemiologic knowledge and clinical trials know-how Paediatric Infectious Disease knowledge & expertise Specific virology expertise Epidemiologic data and expertise Detailed knowledge & expertise in paediatric oncology, access to paediatric oncologists' mailing list, general support
Impact Bate et al (2011, 2012), Fisher et al (2011). We obtained funding from NIHR (RfPB stream) for a pilot trial on which I was a coapplicant (CI Paul Heath at SGUL). It proved extremely difficult to recruit to the study which therefore had the effect of showing that a full trial would not be possible. This was a multidisciplinary collaboration: paediatric immunology, infectious diseases, virology, paediatric oncology, medical statistics, health economics, epidemiology
Start Year 2009
 
Title New genes 
Description My group has delineated novel genetic disorders that impair human immunity - these are candidates for diagnostic testing by gene sequencing 
Type Diagnostic Tool - Non-Imaging
Current Stage Of Development Initial development
Year Development Stage Completed 2011
Development Status Under active development/distribution
Impact Potential for earlier intervention in life-threatening primary immunodeficiency with confirmed molecular diagnosis 
 
Description Jeffrey Modell Foundation diagnostic centre launch 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Type Of Presentation Keynote/Invited Speaker
Geographic Reach Regional
Primary Audience Health professionals
Results and Impact Launch event with 40+ attendees 30 Nov 2012 included spirited panel discussion re patient experiences and how to promote adherence to therapy and clinic attendance


Input from families into planned work with medical sociologist into non-health impact of next generation sequencing
Year(s) Of Engagement Activity 2012