(101IDP1004-1) Development of Anti-Enterovirus Agents Based on Viral RNA Polymerase as the Target (I)

Enterovirus 71 (EV71) infection can cause neurological complications, including aseptic meningitis, encephalitis, poliomyelitis-like paralysis, neurogenic cardiopulmonary failure and even death in young children. Infants, after EV71 infection with complications, reportedly suffer from neurological sequelae and delayed neurodevelopment. In 1998, a large outbreak of EV71 infection occurred in Taiwan, resulting in almost 80 fatalities and 405 severe cases. Subsequently, many outbreaks of EV71 infection have been reported in Taiwan with a total of hundreds of verified fatal cases in 2000-2011. EV71 infection also has been reported in many other countries, such as Malaysia, Singapore, Australia, Japan, the United States, Germany and mainland China. Until now, no effective antiviral drug has been available for the clinical treatment of EV71 infection, which highlights the urgency and importance of the development of anti-EV71 agents. By high-through-put screening more than hundred thousands of compounds, our team (Research Center for Emerging Viral Infections, Chang Gung University & Institute of Biotechnology and Pharmaceutical Research, NHRI) has developed two series of compounds that inhibit EV71 replication, including pyridyl imidazolidinones (“Z” compound) and pyrazolo[3,4-d]pyrimidines (“M” compound), targeting viral capsid protein VP1 and 3D polymerase, respectively (we have obtained patents for those compounds). The antiviral efficacy of “Z”compound has been evaluated in the past year and we would like to continue studying the antiviral efficacy for “M”compound in the current proposal. M compound exhibited broad-spectrum activity against other picornaviruses, such as CA9, CA10, CA16, CA24, CB1-6 and echo 9 viruses. Moreover, it also inhibited rhinoviruses that usually cause common cold. Therefore, we believe this compound will have a great potential to be commercialized. The specific aims for this project are following: (1) To examine the antiviral efficacy in new born mouse model challenged with EV71. New born mouse model for EV71 infection will be used first to test the antiviral efficacy for M compound (EV71 3D polymerase inhibitor) since this model is widely used for EV71 research. Infected mice will be treated with M or M+Z at different concentrations. (2) To test the antiviral efficacy in mice carrying EV71 receptor. SCARB2 and PSGL-1 that are absent in mice have been characterized as EV71 receptors. Therefore, mice carrying those receptors will be generated by Dr. Shih-Jen Liu (our collaborator in NHRI) and Dr. Chiaho Shih (Academia Sinica) either by AAV-delivery system or by transgenic route. The antiviral efficacy of M and M+Z compounds will be examined in this animal model. (3)To investigate whether M compound can inhibit 3D polymerase-associated impairment of host cell splicing machinery. Although enterovirus replicates in cytoplasm, our preliminary results demonstrated that EV71 3D polymerase entered nucleus in the early times of post-infection. 3D interacted with a splicing factor, Prp8, and inhibited host cellular mRNA splicing. We would like to know whether M compound can protect host cell through rescuing its splicing function.

Project ID:PC10106-0042
External Project ID:NSC101-2325-B182-015