Monday 7 December 2015 at 3:00pm

Title: “Controlling disease in aquaculture: Antiviral immunity in oysters”

Speaker:
Dr. Timothy Green, Macquarie University, Department of Biological Science, Sydney, Australia

Abstract:
Infectious disease poses the biggest threat to production of food by aquaculture. Diseases caused by viruses are spreading around the world and these viral diseases have significantly impacted global oyster production. In particular, emergence of a new variant of the Ostreid herpesvirus (termed OsHV-1 μVar) has caused significant mortalities of farmed Pacific oysters (Crassostrea gigas). There is currently no satisfactory method to control this disease. My research focuses on identifying the antiviral immune responses of C. gigas to develop novel solutions for managing OsHV-1. This work also addresses fundamental questions in immunology and biomedicine.

Evolution of the interferon pathway. The type I interferon-pathway is a powerful antiviral response that can control most, if not all, virus infections. The vertebrate innate immune system detects virus-derived nucleic acids to trigger the type I interferon pathway, leading to the transcription of hundreds of interferon-stimulated genes (ISGs) that exert antiviral function. The interferon pathway was thought to exist only in vertebrates because genomes from model-invertebrates do not encode interferon or ISGs. However, the oyster genome encodes many ISGs. My research has shown that the oyster immune system can recognise viral mimics [poly(I:C)] to trigger the transcription of ISGs via a protease susceptible factor (cytokine). This response provides protection against OsHV-1 for at least one month. Furthermore, in-vitro studies have shown oyster ISGs retain direct antiviral activity. These findings will be discussed in relation to the evolution of the interferon pathway and the prospects for developing novel therapeutic treatments for controlling OsHV-1 in oyster aquaculture.

Host: Dr. Russell Hill, Ph.D.