CRISPR-based anti-viral therapeutics to eliminate EBV-associated post-transplant lymphoproliferative disease

DESCRIPTION provided by applicant Post transplant lymphoproliferative disease PTLD is one of the most serious and potentially fatal post transplant complications Frequently PTLD is triggered in the transplant recipient by the transfer of latent Epstein Barr virus EBV present in the donor organ or tissue The risk of PTLD is even higher when the donor is EBV seropositive and the recipient seronegative Pervasiveness of EBV infection in the population is such that avoiding donor grafts infected with EBV is not a viable strategy Current clinical practices of PTLD prevention requires patients to undergo long term prophylactic antiviral regimens frequent monitoring via blood draws and adjustment of immunosuppression dosage which can potentially lead to graft rejection All these lead to high cost and high patient morbidity There is also currently no antiviral drug that can treat the latent EBV infection because existing antiviral drugs only target proteins and as such can only attack actively replicating virus Overall there is need to develop a more efficacious and specific way to prevent PTLD and its associated co morbidities The long term objective of this proposal is to eliminate the risk of donor derived EBV associated PTLD for the annual tissue and organ transplant recipients in the US It is hypothesized that a highly specific anti viral therapeutic using CRISPR Cas to directly target destruction of the EBV DNA genome would be able to eliminate the latent EBV reservoir in donor allografts By treating the graft ex vivo prior to transplantatio using this nuclease based technology the risk of donor EBV derived PTLD is eliminated Preliminary results demonstrate that this technology can successfully reduce viral load in patient derived Burkittandapos s lymphoma cells with latent EBV infection and can induce dramatic proliferation arrest reactivation of apoptotic pathways These results demonstrate success of this technology in eliminating latent EBV virus from a cell line without observing any obvious cytotoxicity thus this proposal aims to extend this work and evaluate the feasibility of this therapeutic approach in primary human blood samples in the context of hematopoietic cell transplants HCT This Phase I study will lay the foundation for future work to demonstrate efficacy and safety of this therapeutic in animal models and for solid organ transplant applications and eventually for human trials Specific Aim Establish the efficacy of CRISPR Cas anti viral therapeutics in eliminating EBV infection from naturally infected EBV seropositive bone marrow samples and evaluate associated effects on HSC function Specific Aim Investigate the safety of CRISPR Cas anti viral therapeutics in the context of eliminating EBV from EBV primary bone marrow samples and optimize treatment conditions to minimize off target effects on human host genome PUBLIC HEALTH RELEVANCE Post transplant lymphoproliferative disease PTLD is a type of blood cancer that can occur spontaneously after a patient receives a solid organ or bone marrow blood stem cell transplant and is one of the most serious and potentially fatal post transplant complications Frequently PTLD is triggered in the transplant recipient by the transfer of latent Epstein Barr virus EBV present in the organ or tissue that was transplanted from the donor especially if the transplant recipient is a child who has no prior immunity to EBV the risk is even higher This proposed research is relevant to public health because it seeks to develop a new therapeutic for highly specific treatment of latent EBV infection present in the donor tissue organs to eliminate the infection prior to transplantation If the research is successful t will prevent the occurrence of donor derived EBV associated PTLD for the annual tissue and organ transplant recipients in the US