Our laboratory has previously shown that autophagy (ATG) genes play an important role in host defense against viruses and intracellular bactena. Recently, we developed a potent autophagy-inducing peptide (Tat-Beclin 1) which induces autophagy through disruption of Beclin 1/GAPR-1 complex and which has in vitro antiviral and antibacterial activity and improves clinical outcomes in mice infected with chikungunya virus and West Nile virus (Shoji-Kawata et al. Nature 2013). The overall goals of this proiect will be to develop a semioptimized lead compound with broad-spectrum anti-infective activity based on the autophagy-inducing peptide, Tat-Beclin 1, and/or disruption of the interaction between Beclin 1/GAPR-1. and to identify new drugable host targets that upregulate viral autophagy. These goals will be accomplished in four specific aims.
In aim 1, we will use an iterative process involving structure-based design peptide-mutation analysis, and synthetic chemistry to develop a peptide-like molecule with optimized stability, autophagy-inducing activity, and anti-infective activity, and we will also evaluate whether Tat-Beclin 1 has anti-infective activity in animal models of tuberculosis (this project) and S. Typhimurium (Project 2) and T. gondii (Project 3).
In aim 2, we will further characterize the Beclin 1/GAPR-1 interaction and the biological functions of GAPR-1 in autophagy regulation and antimicrobial host defense.
In aim 3, will perform a genome-wide siRNA screen to identify genes that regulate virus-induced autophagy, using Sindbis virus as a model for positive-strand viruses that are potential agents of biothreat, such as chikungunya and West Nile virus, and we will identify the mechanisms of action of such genes and their antiviral roles in mouse models of chikungunya and West Nile virus pathogenesis.
In aim 4, we will evaluate the efficacy of autophagy-inducing small molecule compounds identified in Project 4 in inhibiting chikungunya virus. West Nile virus, and M. tb replication in vitro and in decreasing West Nile virus, chikungunya virus, and M. tb pathogenesis in mice. Thus, by further development of an autophagy-inducing peptide that already has known in vivo activity against West Nile virus and chikungunya virus, combined with a genome-wide screen to identify new host genes that regulate virus-induced autophagy, combined with testing autophagy-inducing small molecule compounds identified in other projects of this CETR for efficacy in the treatment of West Nile virus and chikungunya virus infection, we will use a multi-pronged and collaborative approach to identify candidate autophagy-inducing compounds with broad-spectrum anti-infective activity against viruses and intracellular pathogens
The development of therapeutics that prevent infection by a broad range of pathogens is an urgent and unmet need for drug discovery. The project will use several concurrent approaches to lead to the development of such drugs, focused both on optimizing existing strategies discovered by our laboratory and on discovering new strategies which are designed to upregulate, the broad-spectrum anti-infective host innate immunity pathway called autophagy
|Xu, Xiaojin; Araki, Koichi; Li, Shuzhao et al. (2014) Autophagy is essential for effector CD8(+) T cell survival and memory formation. Nat Immunol 15:1152-61|
|Choi, Jayoung; Park, Sunmin; Biering, Scott B et al. (2014) The parasitophorous vacuole membrane of Toxoplasma gondii is targeted for disruption by ubiquitin-like conjugation systems of autophagy. Immunity 40:924-35|
|Karst, Stephanie M; Wobus, Christiane E; Goodfellow, Ian G et al. (2014) Advances in norovirus biology. Cell Host Microbe 15:668-80|