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Published: 6 March 2015

Recent developments in virology by Australian researchers

Joseph R Freitas and Suresh Mahalingam

Institute for Glycomics, Griffith University, Gold Coast, Queensland

Virology is a growing field within Australia. Increased funding is being allocated to discovering how viruses interact with their host/vectors(s) and to the development of better treatments and vaccines. There have been many recent exciting new developments in Australian virology. Space limitations mean that we can only highlight a small number of these achievements in this brief overview of the current virology landscape in Australia.

The increasing prevalence or re-emergence of certain alphaviruses, such as Ross River virus (RRV), Sindbis virus, and Chikungunya virus, is a cause for concern and has attracted increased research interest in recent years. These viruses are known as arthritogenic alphaviruses because they cause arthritis-like symptoms. The ability of these viruses to directly induce bone pathology has remained poorly defined to date. Chen et al.1 recently shed some light on this issue by revealing that RRV can infect human osteoblasts and that osteoblast infection leads to IL-6-dependent bone loss in a mouse model. This discovery of the interaction between osteoblasts, inflammatory factors and alphaviruses is a plausible explanation for how viruses cause chronic joint pain.

Infections with certain viruses, such as West Nile virus (WNV) and dengue virus, can lead to encephalitis, which is associated with high mortality. Inflammatory cells play a central in the progression of these diseases. Currently there are no specific targeted treatments to modulate the action of inflammatory cells. Getts et al.2 recently demonstrated that infusion of immune-modifying microparticles (IMPs) into WNV-infected mice significantly reduced the symptoms of central nervous system infection. The continued injection of IMPs to mice over several days led to an improved survival rate. Similar therapeutic effects were shown for other inflammation-mediated diseases. The therapeutic potential of such IMPs for a variety of immune-related disorders looks to be very promising.

Dengue (DENV) is a mosquito-borne virus that infects hundreds of millions of people annually. It has a widespread geographical prevalence that continues to expand. There is an urgent need for an effective vaccine against DENV. However, this has proven difficult due to the virus having four different serotypes, with a general consensus that a successful vaccine will need to induce immunity to each specific serotype. The identification of antibodies with broad cross-reactivity to all serotypes by Dejnirattisai et al.3 led to the discovery of a novel DENV epitope, which has high potential for use as a successful vaccine antigen. Although this study was performed outside of Australia, the threat of DENV in Australia and the strong collaborative input from University of Melbourne researchers merits its mention here.

Viruses with the ability to pass from animals to humans (‘zoonotic viruses’) are very unpredictable because they have the potential to mutate and become deadly in new hosts. The most notable local example of this is the Hendra virus outbreaks that occurred over the past two decades. Research into this virus and its natural hosts led to the successful development and deployment of a vaccine against Hendra in 20124. A newly identified virus found in Australian bats, dubbed Cedar virus, by Marsh et al.5 in 2012 was found to be very similar to the Hendra and Nipah viruses. The one key difference is that it does not cause disease in several mammals that are susceptible to Hendra and Nipah. This fascinating discovery will no doubt assist scientists to understand what exactly it is that makes certain viruses deadly and others less so.

Norovirus (NoV) is the leading cause of gastroenteritis worldwide and is known to cause thousands of deaths in developing countries. Most outbreaks occur within institutional settings such as hospitals and aged-care facilities. One particular genotype of the virus is responsible for the majority of infections, the genogroup II genotype 46. Since current treatment for NoV infections is largely preventative, there is an urgent need for an effective vaccine or antiviral. By using high throughput screening methods against the RNA polymerase of NoV, Eltahla et al.7 identified a very promising target for development of effective antivirals against this disease.

With these and the many other researchers around Australia currently active in the field, we can expect continuing major advances in the discipline of virology in 2015 and in the years to come.

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