Novel interventions for gammaherpesvirus infection and AIDS-Related Malignancies

Division Of Basic Sciences - Nci

Investigators

Linked publications & trials

Abstract

(1) To overcome current challenges in the development of herpesvirus vaccines, my collaborators and I devised a codon-shuffled complementing gene method to grow high titer replication-dead virus stocks. This replication-dead virus is mutated in a critical gene common to KSHV that is essential for lytic gene expression. We determined that two administrations of this vaccine candidate generate virus-specific B and T cell responses. We also found that vaccination is protective against acute virus replication upon wild-type virus challenge. Building upon the success of this initial approach, we have designed new recombinant viruses that inactivate other viral genes essential to replication and latency of gammaherpesvirus, including KSHV. This is a novel vaccine strategy to generate a wide repertoire of B and T cells against structural and non-structural gene products. Our goal is to reduce oncogenic viral loads and associated-cancer burdens in infected individuals, especially high-risk individuals with HIV/AIDS. (2) In a second project, CRISPR is a gene-editing system that we are developing to neutralize gammaherpesviruses in the cells they infect. This system must be engineered for precision to prevent off-target damage to the host for efficiency to inactivate multiple copies of herpesvirus genomes. We successfully reduced murine gammaherpesvirus replication by CRISPR editing of viral genomic elements. We next applied a modified strategy to deliver guide RNAs that target viral genes and repetitive elements in the multiple sites of the EBV genome. Next generation sequencing is being used to characterize the types of mutations generated and we are examining how this CRISPR system impacts latency and reactivation of EBV in a broad array of B cells and epithelial cells that EBV is known to infect and transform. (3) I am analyzing the host immune response in the peripheral blood mononuclear cells of patients in HAMB clinical trials. We are using flow cytometry to examine if the innate and adaptive immune response differs between HIV+ and HIV- patients. We also study if the immune response changes with the chemotherapies and immunotherapies that are used to treat these patients in the clinical trials. The goal is to identify immune correlates of the clinical response for non-responders and responders to find effective therapies for AIDS associated malignancies.