We recently demonstrated that NLRP3 is critical in inflammasome activation by herpes simplex virus type 1 (HSV-1), and our preliminary data indicate that leucine-rich repeat kinase 2 (LRRK2) enhances NLRP3 signaling. We found that the common LRRK2 mutation G2019S enhances HSV- 1 pathology in mice without altering viral replication. These results point to a novel role for LRRK2 in inflammasome signaling and HSV-1 pathogenesis. We hypothesize that LRRK2 modulates inflammasome signaling in response to HSV-1 infection and that the G2019S mutation further enhances inflammasome activation in vivo, leading to more severe eye, skin, and central nervous system (CNS) pathology after HSV-1 infection. LRRK2 has not been studied in human viral infection, and these represent the first studies to define its role in the pathogenesis of a common neurotropic human viral infection. In Aim 1, we will identify how LRRK2 associates with NLRP3, the critical inflammasome adapter in HSV-1 infection, and how mutations in LRRK2 alter inflammasome signaling in the context of HSV-1 infection. For Aim 2, we will determine how LRRK2 alters the inflammasome response to HSV-1 using LRRK2 transgenic mice and mice with inflammasome gene disruptions. Additionally, the PI will gain critical skills and expertise necessary to study the innate immune response to HSV-1 and other herpesviruses. The proposed career development plan and research aims will provide a pathway to a career as an independent investigator studying the interactions between herpesviruses and the innate immune system.