EpsteinBarr Virus

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Epstein-Barr Virus

• 289,000 Cases of Cancer
• 30,000 Result from Viral Infection

By Andrew Briggs, Christopher Cammies, Cassie
Hall David Lewis
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The Epstein-Barr Virus (EBV)

• The virus is a member of the herpes family
• 95 of people contain antibodies against the
  virus
• Infection is controlled by T Cell Response

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Tumours caused by EBV
Infection by EBV
Infection of B Cells
Infection of Epithelium
Malaria / c-myc translocation
Suppressed Immune System
Genetic Changes
Failure of virus to replicate
Post-transplant lymphoma
Burkitt lymphoma
Hodgkins lymphoma
Nasopharyngeal carcinoma
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The Therapeutic Vaccine

• Immunotherapy is interested in targeting virus
  associated tumours with cytotoxic T cells,
  specific for viral antigens.
• Since 95 of the population contain antibodies to
  EBV, a traditional vaccine would have little
  effect.
• Previous studies have designed therapeutic
  vaccines for EBV associated tumours containing
  the common EBNA3 antigens.
• Nasopharyngeal carcinoma doesnt contain this
  antigen.
• A therapeutic vaccine has been proposed by GS
  Taylor et al for EBV associated carcinomas not
  containing EBNA3 antigens.

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Fusion protein MVA-EL

• Nasopharyngeal carcinoma
• cells contain the nuclear antigens
• EBNA1, LMP1 and LMP2. Not EBNA3
• which is common in other EBV
• associated tumours.
• LMP2 is a source for eliciting
• a CD8 response.
• EBNA1 is immunodominant over
• LMP1 and LMP2 as a target for CD4
• T cell response.

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Can epitope specific CD8 T cells be reactivated
by exposure to MVA-EL infected stimulators?

• Results show an efficient expansion of FLY/A2 and
  LLW/A2 specific memory cells following MVA-EL
  infection.This is higher than LCL
• Dendritic cells stimulated with MVA-EL expanded
  the CD8 T cells specific for SSC/A11 (results
  not shown).

YES

• ELISPOT assay- results are the number of
  epitope-specific spot forming cells per million
  cells in the culture
• Were recorded on days 11 and 17 post-stimulation
• PBMCs came from EBV immune donors of relevant HLA
  class I type these were then co-cultured with
  MVA-EL or LCL

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Can MVA-EL EBNA1 specific epitopes produce a
CD4 T cell expansion?

• Parallel series of experiments comparing the
  ability of MVA-EL infected dendritic cells and
  LCL to expand EBNA1 epitope specific CD4 T
  memory cells.
• Results show a significant difference between the
  ability of autologous LCL and dendritic cells
  infected with MVA-EL

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Further testing of CD4 T-cells

• Results indicated that the PQC c1 was antigen
  specific.
• It can be assumed that EVA-EL is able to
  directly access the HLA class II presentation
  pathway due
• to comparisons with LAMP-E1?GA results.
• Results confirmed that it is the endogenous EL
  protein that is processed for the HLA class II
  pathway. As the EL fusion protein was inactivated
  after UV exposure.

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Future Experiments

• This study is in vitro so we propose the
  following in vivo Study required.
• Misako Yajima generated a mouse model
  (NOD/Shi-Scid IL-2Rynull with injected human
  Haematopoietic stem cells) capable of
  reconstituting human immune response to
  Epstein-Barr virus in mice.
• Vaccination of EBV-infected mice with MVA-EL,
  with a control of mice infected without
  vaccination.
• Effectiveness of the vaccine to be screened over
  3 month period. Screening via assays of virus
  numbers, carcinoma cells present and symptoms.

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Future Experiments cont.

• EBV expresses different latent proteins
  (including EBNA 1,2, 3a,3b,3c and LP). Repeats of
  this experiment using the different variants of
  EBV, could potentially produce therapeutic
  vaccines.
• Generate an in vitro response to a different
  array of virus, primarily expanding to other
  virus inducing carcinomas, such as human
  papillomavirus (HPV).

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References

• Taylor, G. S., Haigh, T. A., Gudgeon, N. H. et
  al. (2004) Dual stimulation of Epstein-Barr virus
  (EBV)-specific CD4 - and CD8 - T-cell responses
  by a chimeric antigen construct potential
  therapeutic vaccine for EBV-postive
  nasopharyngeal carcinoma. Journal of Virology
  78(2) 768-778
• Rochford, R., Cannon, M. and Moormann, A. (2005)
  Endemic Burkitt's lymphoma a polymicrobial
  disease? Nature Reviews Microbiology 3 182-187
• Yajima, M., Imadone, K., Nakagawa, A. et al.
  (2008) A new humanized mouse model of
  Epstein-barr virus infection that reproduces
  persistent infection, lymphoproliferative
  disorder and cell mediated and humoral immune
  responses. Journal of infectious disease society
  of america 673-682