Month: August 2018

Fighting Virus with Bacteria

Almost four years ago scientists intentionally released millions of mosquitoes onto an Australian city in an effort to lower the incidence of arboviruses (viruses like Dengue and Zika that can be transmitted via the bite of a mosquito). While adding more mosquitoes to the population may seem counterintuitive, the addition of these insects actually did help to lower the rate of transmission of at least one arbovirus.  However, viral prevention wasn’t due to just having more mosquitoes around but moreso due to the bacteria these new mosquitoes were carrying.

The mosquitoes of interest were infected with Wolbachia spp. an insect-specific bacterium that has been known for a long time to cause cytoplasmic incompatibility between mating mosquitoes. This means that if an uninfected female mates with a Wolbachia-infected male, the resulting offspring will not be viable.  Additionally, Wolbachia infection has been shown to shorten mosquito lifespan and lower the viral infection rates of the mosquitoes themselves.  Taken together this bacterium offers an attractive and novel solution for controlling the spread of arboviruses especially given that current prevention methods like insecticides, mosquito nets, and crude treatments and vaccines, are not fully effective.

The aforementioned study, spearheaded by Scott O’Neill at Monash University, utilized Wolbachia as a method of controlling arbovirus spread and the results from this roughly four year trial hold promise.  The study followed the number of cases of Dengue, an arbovirus that causes mostly mild symptoms but can be fatal especially for children, after the release of Wolbachia-infected mosquitoes.  Only 4 cases of Dengue were locally acquired in the 4 years following mosquito release verses 54 cases in the 4 years prior.  These results become more exciting when you consider that Wolbachia infection can lower the rate of multiple arboviruses simultaneously. Although the study did not report on the incidence of other arboviruses like Zika virus and chikungunya virus, it would not be surprising to see the infection rate of these pathogens also decrease following mosquito release.

While complete eradication of the arboviruses is an enticing scenario, much more work needs to be done before this goal can come to fruition. To address this, there are multiple ongoing large-scale studies investigating Wolbachia as a means of arbovirus control especially in regions with high incidences of disease. Additionally, Wolbachia infection is also being studied for its efficacy against preventing the spread of Malaria. While Malaria is not caused by an arbovirus but instead results from infection of the Plasmodium parasite, it is still spread primarily through the bite of a mosquito and therefore could theoretically be influenced by Wolbachia infections in host mosquitoes. The results from this study are just the beginning and offer hope that someday mosquito bites can evolve from the life-threatening events they currently are for so many people to minor inconveniences.

Ashley

(Picture from Dado Galdieri featured in Nature)

Introduction to My Research and Me

Greetings to any and all (family, friends, co-workers etc.) who have ventured to my blog.  I made this blog and intend to use this platform as a chance to better my science writing and reporting skills and also to help explain science in a way that is more accessible to everyone.  Science education and outreach to me has always just meant explaining my research or a new discovery to family and close friends.  But now, as I begin the journey towards a graduate degree, I feel as though my outreach should extend beyond that (or at least try).

So, to kick off my blog, I’m going to give some background on the research that gets me excited and out of bed in the morning and also talk about the general focus of the lab that I work in.

My lab is a virology and immunology lab meaning we study viruses and how they interact with the immune system. Within the many components of the immune system, our lab has a particular interest in a group of proteins called the IFITMs (which stands for Interferon-Induced Transmembrane Proteins). These IFITMs have been shown to stop the fusion of some viruses with host cells in turn helping to prevent the spread of the virus. IFITM expression is therefore considered beneficial to humans, and individuals with mutant IFITMs are more likely to get sick from viral infections.

My specific research project focuses on these IFITMs and how they could potentially play a role in the birth defects associated with microbial infection during pregnancy. For example, Zika virus caused and continues to cause such a scare because it is associated with the birth defect microcephaly (babies are born with small or underdeveloped heads). A less well-known birth defect caused by Zika virus infection is spontaneous miscarriage. However, a recent scientific breakthrough has shown these miscarriages are actually the product of our own immune response and NOT the virus! The exact  mechanism of how our immune system causes these miscarriages is still unclear and that’s where my project picks up.  We believe the IFITMs, a product of the human immune response to viral infection, may be inhibiting the formation of the placenta.  If the placenta does not form properly early in pregnancy, the fetus will not be able to survive and will be spontaneously aborted (i.e. a miscarriage will occur).  Thus by identifying the mechanism of the human immune response (specifically the IFITMs) in Zika virus-associated miscarriages, we can help prevent them from occurring.

Ashley

(Picture from Science Magazine)