containing an epidemic

Can bats – the carriers of many deadly diseases – help humans survive the next pandemic?

Bats are believed to be hosts for several of coronaviruses that causes diseases like SARS and MERS.

In 2003, severe acute respiratory syndrome (SARS) infected a total of 8,098 people worldwide. First reported in China, it spread rapidly through more than two dozen countries in North America, South America, Europe and Asia.

You may not know that bats were implicated as a wildlife “reservoir” of the virus that caused the outbreak and killed 774 people.

SARS was caused by a coronavirus (CoV). Coronaviruses in general infect humans on a regular basis, often leading to symptoms of the common cold: Coughing, sore throat, runny nose, sneezing and fever. But some, like SARS-CoV, jump species to humans from other animals, causing disease and often death.

Bats are believed to be hosts, or reservoirs, for several of these coronaviruses. They are also speculated to be the original source of the Middle East respiratory syndrome (MERS)-CoV that causes an illness, first reported in 2012, from which 30 to 40 per cent of infected patients have died.

And, interestingly, laboratory studies and field observations have shown that bats infected with these viruses do not develop any clinical signs of disease.

Why is this? What adaptations in the bat immune system allow them to survive infections with these viruses? Can they help prevent the next pandemic? These are the questions that drive our research.

Karen Mossman has been studying immune response modulation by viruses for more than 25 years. Arinjay Banerjee is exploring the immune responses in bat and human cells to different viruses, including MERS-CoV, as part of his PhD research.

We hope these studies might open up avenues for identification of novel therapeutics for humans and help us design strategies to increase our odds of surviving infections with these highly pathogenic viruses.

Viruses shut down the immune response

The reason that coronaviruses causing SARS and MERS make us so sick is that, like most other viruses, they have evolved diverse strategies to shut down our first line of defence, the innate immune response.

Immune response is activated when a virus infects the first cell in our body. The cell produces molecules that hinder the spread of the virus. These molecules also prime neighbouring cells to resist infection with the virus.

Inhibiting this immune response is thus an advantage for the virus.

3D image of the Middle East respiratory syndrome or MERS virus (Image: Wikimedia Commons)
3D image of the Middle East respiratory syndrome or MERS virus (Image: Wikimedia Commons)

SARS-CoV and MERS-CoV make several proteins that inhibit these cellular defence responses, allowing the virus to spread and the disease to progress in an infected individual.

The “jump” from bats to humans

Viruses such as coronaviruses have likely evolved for a very long time with bats, thus allowing both bats and viruses to reach equilibrium where they can co-exist.

Generally, hosts and viruses that have co-evolved like this adapt their defence and counter-defence strategies to establish an optimal environment for both participants in this evolutionary race.

However, sometimes these viruses grow to high numbers and cause disease or spread from their evolutionary hosts to other animals and to humans if this “optimal” environment is disturbed.

As bats have been evolving for 50 million years, they have had a long time to adapt to their viruses. The question remains then: Why do some of these viruses occasionally “jump” from bats to other species to cause significant disease?

The only mammal capable of true flight

Since coronaviruses similar to MERS-CoV and SARS-CoV have been detected in bats without symptoms, it follows that bats must employ a unique immune response to survive infections.

Bats carry the most viruses per mammalian species, even more than rodents. And bats experimentally infected with MERS-CoV do not develop signs of disease.

Understanding how bats can successfully co-exist with more than 200 different viruses is of growing interest to researchers. Several hypotheses have emerged about this unique ability of bats to resist virus-induced disease. Speculations include co-evolutionary adaptations and the ability to fly.

Bats are the only mammals capable of true flight. During flight, the body temperature of bats rises to over 40℃. This resembles a fever response in humans, and fever is known to prime the immune response.

Is it possible that bats have an immune response that is always primed, in part due to the increase in their body temperatures during flight?

Metabolic rate is also increased during flight, which produces reactive oxygen radicals that can damage cellular DNA. There is evidence that genes involved in antiviral responses are positively selected due to their role in DNA repair as well. Thus, the ability to fly may have caused DNA repair genes to evolve for better functionality, which in turn may have led to the evolution of a more robust immune response in bats.

Bats may carry the Ebola virus without symptoms, and scientists suspect them to be the source of the epidemic. (Image: European Commission DG ECHO/Global Panorama/Flickr)
Bats may carry the Ebola virus without symptoms, and scientists suspect them to be the source of the epidemic. (Image: European Commission DG ECHO/Global Panorama/Flickr)

Scientists also speculate that since bats are primed to resist infections with viruses due to an over-active antiviral response in their cells, their viruses have co-evolved to make increasing amounts of viral proteins that can modulate these immune responses.

When humans are infected with these viruses, the viruses continue to make high levels of these proteins. But human cells are not primed to continuously express high levels of antiviral molecules the way bat cells are. Therefore, immune responses mounted by human cells are probably easily overwhelmed by these viral proteins.

Understanding these intriguing interactions is a work in progress and we are currently trying to understand if MERS-CoV behaves differently in bat cells.

We’re also interested in observing how bat cells respond to infection with MERS-CoV and other viruses. We hope these studies will open up avenues for identification of novel therapeutic targets and molecules, and enhance research into less-studied wildlife viral reservoirs.

Arinjay Banerjee, PhD Candidate in Veterinary Microbiology, University of Saskatchewan and Karen Mossman, Professor and AVP Research, McMaster University.

This article was first published on The Conversation.

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Not just for experts: How videography is poised for a disruption

Digital solutions are making sure it’s easier than ever to express your creativity in moving images.

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Once burdened by unreliable film, bulky cameras and prohibitive production costs, videography is now accessible to anyone with a smartphone and a decent Internet bandwidth. A lay person casually using social media today has so many video types and platforms to choose from - looping Vine videos, staccato Musical.lys, GIFs, Instagram stories, YouTube channels and many more. Videos are indeed fast emerging as the next front of expression online, and so are the digital solutions to support video creation.

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With Vizmato, the creative process starts at the shooting stage itself as it enables live application of themes and effects. Choose from hip hop, noir, haunted, vintage and many more.

The variety of filters available on Vizmato
The variety of filters available on Vizmato

Or you can simply choose to unleash your creativity at the editing stage; the possibilities are endless. Vizmato simplifies the core editing process by making it easier to apply cuts and join and reverse clips so your video can flow exactly the way you envisioned. Once the video is edited, you can use a variety of interesting effects to give your video that extra edge.

The RGB split, Inset and Fluidic effects.
The RGB split, Inset and Fluidic effects.

You can even choose music and sound effects to go with your clip; there’s nothing like applause at the right moment, or a laugh track at the crack of the worst joke.

Or just annotated GIFs customised for each moment.

Vizmato is the latest offering from Global Delight, which builds cross-platform audio, video and photography applications. It is the Indian developer that created award-winning iPhone apps such as Camera Plus, Camera Plus Pro and the Boom series. Vizmato is an upgrade of its hugely popular app Game Your Video, one of the winners of the Macworld Best of Show 2012. The overhauled Vizmato, in essence, brings the Instagram functionality to videos. With instant themes, filters and effects at your disposal, you can feel like the director of a sci-fi film, horror movie or a romance drama, all within a single video clip. It even provides an in-built video-sharing platform, Popular, to which you can upload your creations and gain visibility and feedback.


So, whether you’re into making the most interesting Vines or shooting your take on Ed Sheeran’s ‘Shape of You’, experience for yourself how Vizmato has made video creation addictively simple. Android users can download the app here and iOS users will have their version in January.

This article was produced by the Scroll marketing team on behalf of Vizmato and not by the Scroll editorial team.