Project 1. Gene Expression During HSV-1 Latency and Reactivation Human neurotropic herpes viruses such as HSV cause much disease and suffering. The long-termobjective of this project is to understand the mechanism of herpes simplex virus latency and reactivation atthe molecular level. In this application, we propose to expand our study of the nucleosomal state of the viral DNA, as webelieve that these structures play an important role in regulating viral gene expression. We will continue toexamine the function of stable intron of the latency associated transcript (LAT) genes. Furthermore we willexpand on our finding of differences in cell gene expression in latently infected and normal trigeminalganglia. These goals will be achieved using the techniques of molecular virology and a mouse model ofHSV infection. In the first specific aim, we will determine the distribution and role of the nucleosome in acute infection ofmice. Further studies will relate these results to the situation during viral reactivation. In the second aim, we will continue our study of the functionality of the LAT gene. We will study the 2kbLAT intron, which is found in the nucleus of latently infected neurons yet in the cytoplasm of lytically infectedcells. Our recent studies suggest that the intron plays a role in cellular stress response. We will determinejLAT intron function through studying its structure and the proteins associated with it. Our studies on themechanism of the LAT antiapoptotic effect will be expanded in light of our recent progress. In the third specific aim, we will continue our study of the cell genes that are changed in expression inlatently infected trigeminal ganglia. We wiil perform insitu hybridization to confirm the cell types that arealtered in transcript levels, and immunohistochemistry to identify if the protein products are altered in amountjor distribution. An understanding of these changes will help- us recognize ways in which the latent virusalters the infected sensory neuron, presumably in order to maintain its latency. These studies will continue our investigation of herpes simplex virus latency and reactivation and furtherour understanding of the mechanism of latency in the peripheral nervous system.
