Project Summary/abstract Non-AIDS-defining cancers (NADC) are increasing in HIV-infected individuals (HIVIIs), urging the development of novel therapeutic interventions and model systems to assess HIV’s contribution to tumor pathogenesis. Many HIV-associated cancers result from oncogenic virus co-infections, and the high-risk human papillomavirus (HPV) is prevalent in the development of NADCs, including head-and-neck (HNC) and anal cancers, which are significantly elevated in HIVIIs. Importantly, the HPV viral oncogenes are involved in the transformation and maintenance of these cancers, susceptible to targeted gene therapeutic strategies such as RNAi interference (RNAi). However, a major hurdle preventing the development of therapeutic RNAi for HPV-associated malignancies is delivery. Both viral and non-viral systems have been developed, but viral delivery systems are immunogenic precluding repeat dosing, and non-viral synthetic nanoparticles are challenging to target away from the liver with limited tumor uptake when administered systemically. We have pioneered a non-immunogenic native extracellular vesicle system for the delivery of potent RNAi effectors to drastically advance RNAi-based treatment for HPV-associated NADCs. However, HIVIIs have more aggressive NADCs, which are diagnosed at a younger age with possible treatment resistance with many confounding features including chronic inflammation and immune dysregulation, HIV viral factors that promote angiogenesis and cellular pathways associated with treatment resistance, and possible side effects of antiretroviral therapy (ART), but representative in vivo models are lacking to study the HIV factors affecting NADC progression and drug insensitivity. There is a need to understand the factors affecting tumors in an HIV environment with patient-derived samples, which could be explored through the development of immune-competent in vivo patient models that support HIV infection, recreating a HIV-cancer ecosystem to study NADC pathogenesis. Our long-term goal is to develop innovative interventions and models for the treatment of virally driven cancers emerging in HIVIIs, and we seek to develop these objectives through two distinct aims: 1) characterization of an innovative EV-deliverable anti-HPV treatment to inhibit ADC and NADCs, and 2) the assessment of the cellular profile of HPV-associated HNC tumours from HIV+ and HIV- individuals to inform the development of representative immune-competent HIV murine models for study factors affecting NADCs. Collectively, this work will be impactful by developing innovative targeted treatments and representative models for HPV-associated malignancies prevalent in HIVIIs to address the rising cases of virus-associated cancer in people living with HIV.