Project 4 Project Summary Abstract The goal of this project is to continue to determine how EBV modulates cell growth with particular focus on the BART long noncoding RNAs and to identify potential effects of the presence of EBV infected cells on the growth and expression of HPV infected cells. We have previously shown profound effects of the viral oncogenes, latent membrane proteins 1 and 2, on the growth of cells through activation of distinct signaling pathways and effects on protein levels through ubiquitination and determined that these proteins are secreted in exosomes and can be transferred to uninfected cells. Recently, we have utilized RNASeq to analyze total cellular expression in the AGS epithelial cell line, with or without EBV infection, grown in vitro and as tumors in NOD SCID mice in comparison with the C666 NPC cell line, and the NPC xenografts C15 and C17. The majority of the identified canonical pathways based on two fold changes in expression had decreased activity in vivo. EBV expression was also distinct with greatly increased transcription of the BART non coding RNAs in both NPC and the AGS cells. The significant expression of the viral BART nc RNAs in vivo in the absence of the EBV transforming proteins suggests that they are contributing factors to tumorigenesis. Their effects and potential mechanisms of action are a major focus of this application. EBV persistent infection in the oropharynx has several states of infection with cells that express multiple viral proteins including LMP1 and LMP2, cells that are restricted to BART miRNA and lnc RNA, and cells with some replicative reactivation. It is likely that through EV shedding, EBV may greatly impact other oropharyngeal viral infections. Importantly, HPV throat cancer is now the most rapidly increasing virally associated cancer. The almost universal oral infection with EBV could likely modulate the growth and cellular expression of HPV infected cells and potentially enhance their oncogenic properties. The in vivo interactions of EBV and HPV have not yet been defined. This proposal will determine how the distinct latent EBV infections or permissive infection alter the growth and expression of HPV infected cells.