Project 3-Cameron

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PROJECT SUMMARY / ABSTRACT Oncogenic human papillomavirus (high risk HPV, or hrHPV) is the etiologic agent responsible for more than 90% of cancers of the uterine cervix and the anal canal (anogenital cancers). People living with human immunodeficiency virus (HIV) infection (PLWH) are particularly susceptible to hrHPV mediated anogenital cancers. People infected with high-risk HPV are at increased risk for cancer if the viral genome integrates into the host genome. The mechanisms by which hrHPV integration promotes tumorigenesis have been well described; however, the factors that promote hrHPV integration are largely unknown. The long-term objective of the proposed research is to identify these factors and then design effective interventions to prevent PLWH from developing anogenital cancers. Research has shown that PLWH who have anogenital high-risk HPV infection concurrently with another tumor virus, Epstein-Barr virus (EBV), are 3-6 times more likely to have pre-cancerous dysplasia than people who have anogenital hrHPV in the absence of EBV. This proposal investigates the hypothesis that EBV promotes integration of hrHPV genomes into the host genome by causing DNA damage. The general experimental approach will utilize cervical and anal tissues collected from hrHPV infected women and men to gain a better understanding of the interactions between hrHPV and EBV in anogenital tissue. The spatial relationship between hrHPV and EBV in co-infected tissue is a key determinant of the nature of the mechanistic interactions between the viruses; however, studies to date have failed to identify the cell compartment occupied by EBV in anogenital tissue. Therefore, the first Specific Aim of this proposal is to determine if hrHPV and EBV interact directly by co-infecting the same cell, or if they interact indirectly by infecting proximal but separate cell compartments, using cutting-edge in situ hybridization and immunohisto- chemistry approaches. The second Specific Aim is to begin to elucidate the effects of hrHPV-EBV co- infection on host and virus gene expression networks. Transcript expression in hrHPV-EBV co-infected anogenital tissue will be compared to that of hrHPV infected tissue using high-depth transcriptomics methods. Differential expression of host transcripts will reveal cellular pathways perturbed by hrHPV- EBV co-infection, including the effects of co-infection on DNA damage/repair pathways. Viral gene expression will be observed to determine a) if EBV is expressing latency transcripts associated with DNA damage and oncogenesis; b) if hrHPV is more likely to be integrated in the presence of EBV; and c) if EBV induces the expression of hrHPV oncogenes. Together these aims will inform the working model describing the mechanistic interactions between hrHPV and EBV in the context of anogenital cancer development, which will be further explored in a subsequent R01 proposal. These studies will illuminate opportunities for novel intervention strategies to prevent anogenital cancers in PLWH.