Poster Presentation 64th International Conference of the Wildlife Disease Association 2015

TRAIL to death: Is TNF related apoptosis inducing ligand (TRAIL) a common antiviral mechanism employed by reservoir species? (#174)

Patrick Mileto 1 2 , James Wynne 2 , Beata Ujvari 1 , Michelle Baker 2
  1. Faculty of Life and Environmental Sciences, Deakin University , Geelong, Victoria, Australia
  2. CSIRO Australian Animal Health Laboratory, Hamlyn Heights, VIC, Australia

While certain species (e.g. bats and ducks) are capable of carrying viruses asymptotically, other species (e.g. humans and chickens) succumb to infection and develop symptoms of disease. The reason why certain species are subject to disease though other species are resistant remains an enigma and a question that urgently needs answering. Mechanisms that reservoir species use to regulate viral infections are largely unknown. Previous research has shown apoptosis, or programed cell death, may play an important role in the antiviral response of reservoir hosts (Wynne et al, 2014, Kuchipudi et al, 2012). Apoptosis is a naturally occurring mechanism that is critical in biological development and the immune system. Apoptosis can be induced through a number of signalling molecules, including TRAIL. TRAIL, is a secreted molecule that can bind to viral infected cells, through their interaction with death receptors, to induce apoptotic cell death. Our laboratory has previously shown that bat kidney, but not human kidney cells, undergo TRAIL mediated apoptosis in response to Hendra virus, a highly pathogenic bat borne virus. In the present study we investigated the induction of TRAIL mediated apoptosis across a range of bat and human cells. By using enzymatic assays combined with real-time PCR we demonstrate that bat cells are hypersensitive to apoptosis, evidenced through increased caspase 3/7 activity. We also showed that bat cells have a significant induction of TRAIL mRNA and its associated receptor. Our findings highlight the important antiviral response of TRAIL in bats. We hypothesise that the rapid induction of apoptotic cell death in viral infected cells, may be mechanisms by which bats control viral replication. Future research in our laboratory will examine this pathway in other reservoir host models, including influenza infected duck and chicken cells.