The Times Australia
The Times World News

.
Times Media

.

Viruses aren't always harmful. 6 ways they're used in health care and pest control

  • Written by Thea van de Mortel, Professor, Nursing, School of Nursing and Midwifery, Griffith University
Viruses aren't always harmful. 6 ways they're used in health care and pest control

We tend to just think of viruses in terms of their damaging impacts on human health and lives. The 1918 flu pandemic[1] killed around 50 million people. Smallpox[2] claimed 30% of those who caught it, and survivors were often scarred and blinded. More recently, we’re all too familiar with the health and economic impacts of COVID.

But viruses can also be used to benefit human health, agriculture and the environment.

Viruses are comparatively simple in structure[3], consisting of a piece of genetic material (RNA or DNA) enclosed in a protein coat (the capsid). Some also have an outer envelope.

Viruses get into your cells and use your cell machinery to copy themselves. Here are six ways we’ve harnessed this for health care and pest control.

Read more: How do viruses get into cells? Their infection tactics determine whether they can jump species or set off a pandemic[4]

1. To correct genes

Viruses are used in some gene therapies to correct malfunctioning genes[5]. Genes[6] are DNA sequences that code for a particular protein required for cell function.

If we remove viral genetic material from the capsid (protein coat) we can use the space to transport a “cargo” into cells. These modified viruses are called “viral vectors[7]”.

Viruses consist of a piece of RNA or DNA enclosed in a protein coat called the capsid. DEXi[8]

Viral vectors can deliver a functional gene[9] into someone with a genetic disorder whose own gene is not working properly.

Some genetic diseases[10] treated this way include haemophilia, sickle cell disease and beta thalassaemia.

2. Treat cancer

Viral vectors can be used to treat cancer.

Healthy people have p53, a tumour-suppressor gene. About half[11] of cancers are associated with the loss of p53.

Replacing the damaged p53 gene using a viral vector stops the cancerous cell from replicating and tells it to suicide (apoptosis[12]).

Viral vectors can also be used to deliver an inactive drug[13] to a tumour, where it is then activated to kill the tumour cell.

This targeted therapy reduces the side effects otherwise seen with cytotoxic (cell-killing) drugs.

Here’s how treatment, called gene therapy, works.

We can also use oncolytic[14] (cancer cell-destroying) viruses to treat some types of cancer.

Tumour cells have often lost their antiviral defences. In the case of melanoma[15], a modified herpes simplex virus can kill rapidly dividing melanoma cells while largely leaving non-tumour cells alone.

3. Create immune responses

Viral vectors can create a protective immune response to a particular viral antigen.

One COVID vaccine[16] uses a modified chimp adenovirus (adenoviruses cause the common cold in humans) to transport RNA coding for the SARS-CoV-2 spike protein into human cells.

Read more: How the puzzle of viral vector vaccines was solved, leading to today’s COVID-19 shots[17]

The RNA is then used to make spike protein copies, which stimulate our immune cells to replicate and “remember” the spike protein.

Then, when you are exposed to SARS-CoV-2 for real, your immune system can churn out lots of antibodies and virus-killing cells very quickly to prevent or reduce the severity of infection.

4. Act as vaccines

Viruses can be modified to act directly as vaccines themselves in several ways[18].

We can weaken a virus (for an attenuated virus vaccine) so it doesn’t cause infection in a healthy host but can still replicate to stimulate the immune response. The chickenpox vaccine works like this.

The Salk vaccine for polio uses a whole virus that has been inactivated (so it can’t cause disease).

Others use a small part of the virus such as a capsid protein to stimulate an immune response (subunit vaccines).

An mRNA vaccine packages up viral RNA for a specific protein that will stimulate an immune response.

5. Kill bacteria

Viruses can – in limited situations in Australia[19] – be used to treat antibiotic-resistant bacterial infections.

Bacteriophages[20] are viruses that kill bacteria. Each type of phage usually infects a particular species of bacteria.

Unlike antibiotics – which often kill “good” bacteria along with the disease-causing ones – phage therapy leaves your normal flora (useful microbes) intact.

A phage
Bacteriophages (red) are viruses that kill bacteria (green). Shutterstock[21]

6. Target plant, fungal or animal pests

Viruses can be species-specific (infecting one species only) and even cell-specific (infecting one type of cell only).

This occurs because the proteins viruses use to attach to cells have a shape that binds to a specific type of cell receptor[22] or molecule, like a specific key fits a lock.

The virus can enter the cells of all species with this receptor/molecule. For example, rabies virus[23] can infect all mammals because we share the right receptor, and mammals have other characteristics that allow infection to occur whereas other non-mammal species don’t.

When the receptor is only found on one cell type, then the virus will infect that cell type, which may only be found in one or a limited number of species. Hepatitis B virus[24] successfully infects liver cells primarily in humans and chimps.

We can use that property of specificity to target invasive plant species[25] (reducing the need for chemical herbicides) and pest insects (reducing the need for chemical insecticides). Baculoviruses[26], for example, are used to control caterpillars.

Similarly, bacteriophages[27] can be used to control bacterial tomato and grapevine diseases[28].

Read more: 'Phage therapy' could treat some drug-resistant superbug infections, but comes with unique challenges[29]

Other viruses reduce plant damage from fungal pests[30].

Myxoma virus and calicivirus[31] reduce rabbit populations and their environmental impacts and improve agricultural production.

Just like humans can be protected against by vaccination, plants can be “immunised[32]” against a disease-causing virus by being exposed to a milder version.

References

  1. ^ The 1918 flu pandemic (blogs.cdc.gov)
  2. ^ Smallpox (www.cdc.gov)
  3. ^ structure (www.ncbi.nlm.nih.gov)
  4. ^ How do viruses get into cells? Their infection tactics determine whether they can jump species or set off a pandemic (theconversation.com)
  5. ^ malfunctioning genes (www.mdpi.com)
  6. ^ Genes (www.genome.gov)
  7. ^ viral vectors (www.nature.com)
  8. ^ DEXi (en.wikipedia.org)
  9. ^ deliver a functional gene (www.nature.com)
  10. ^ genetic diseases (www.mdpi.com)
  11. ^ half (www.ncbi.nlm.nih.gov)
  12. ^ apoptosis (www.ncbi.nlm.nih.gov)
  13. ^ inactive drug (www.ncbi.nlm.nih.gov)
  14. ^ oncolytic (www.ncbi.nlm.nih.gov)
  15. ^ melanoma (www.ncbi.nlm.nih.gov)
  16. ^ COVID vaccine (www.ncbi.nlm.nih.gov)
  17. ^ How the puzzle of viral vector vaccines was solved, leading to today’s COVID-19 shots (theconversation.com)
  18. ^ in several ways (www.hhs.gov)
  19. ^ in Australia (phage.directory)
  20. ^ Bacteriophages (www.ncbi.nlm.nih.gov)
  21. ^ Shutterstock (www.shutterstock.com)
  22. ^ a specific type of cell receptor (www.ncbi.nlm.nih.gov)
  23. ^ rabies virus (www.cdc.gov)
  24. ^ Hepatitis B virus (www.ncbi.nlm.nih.gov)
  25. ^ invasive plant species (pubmed.ncbi.nlm.nih.gov)
  26. ^ Baculoviruses (www.tandfonline.com)
  27. ^ bacteriophages (www.ncbi.nlm.nih.gov)
  28. ^ tomato and grapevine diseases (www.annualreviews.org)
  29. ^ 'Phage therapy' could treat some drug-resistant superbug infections, but comes with unique challenges (theconversation.com)
  30. ^ fungal pests (www.annualreviews.org)
  31. ^ Myxoma virus and calicivirus (csiropedia.csiro.au)
  32. ^ immunised (www.annualreviews.org)

Read more https://theconversation.com/viruses-arent-always-harmful-6-ways-theyre-used-in-health-care-and-pest-control-217379

The Times Features

Sunshine Coast Personal Injury Lawyers: Expert Guidance for Work Accident Claims

When accidents occur in the workplace, they can have profound and lasting effects on a worker's life, both physically and financially. In Queensland's Sunshine Coast, personal in...

iS Clinical's Skincare Secrets for Radiant Party Season Skin

As the festive season approaches, having runway-ready skin is easier than ever with iS Clinical's  top skincare prep tips. Whether you're walking the red carpet or simply stepp...

How to Camp Sustainably in Byron Bay: Eco-Friendly Tips

Camping in Byron Bay is a fantastic way to soak up nature, from beautiful beaches to lush rainforests. It’s no wonder Byron Bay camping is on so many bucket lists! But with more ...

Book a room in Broome as the northwest is best

Looking for a different kind of seaside escape? Done the east coast? Then book a room in Broome to discover why those in the know say the northwest is best, with Broome one of ...

Primary care involves more than GPs. A new review shows how patients can better access care

Australians today are more likely[1] than previous generations to live with complex and chronic diseases, such as diabetes, heart disease and depression. This means they’re mo...

Why Your Credit Score Matters More Than You Think in Australia

Your credit score isn't just a number, it's a reflection of your financial reputation. In Australia, a good credit score can unlock doors to better financial opportunities, while...

Enhance Your Home’s Comfort and Style with Blackout Curtains from 3Hlinen

Creating a comfortable and peaceful home environment often involves choosing the right window treatments. Among the various options available, blackout curtains stand out as a ve...

Is thirst a good predictor of dehydration?

Water is essential for daily functioning and health, and we can only survive a few days[1] without it. Yet we constantly lose water through sweat, urination and even evaporatio...

How doctors use light to diagnose disease

You’re not feeling well. You’ve had a pounding headache all week, dizzy spells and have vomited up your past few meals. You visit your GP to get some answers and sit while they ...

Times Magazine

Everything You Need to Know About Solar Panel Savings

Last year, the U.S. recorded its highest amount of renewable energy usage. It comes at a time where climate change has become an increasing factor in society. To help the Earth, more people have switched to renewable energy sources because they ...

CSIRO and Space Machines partner to test Australian flexible solar cells in space

Space Machines and CSIRO partner to test Australian flexible solar cells in space  SYDNEY, Australia - Thursday 5th August 2021 - Australian in-space transportation provider Space Machines Company (SMC) and CSIRO, Australia's national scie...

What Sets Melbourne's Top Design Agencies Apart From the Rest?

Design- a word that is all about creativity and expression. When you start a business in today's time, your primary aim is for your audience to know you. The key way your audience can know you is to develop a strong visual value.  Businesses in to...

Give Dad the gift of good health this Father’s Day

According to Glenn Cross, chairman of EZZ Life Science, while Father’s Day usually triggers a frenzy of retail shopping among families desperate to buy gifts for dad to spoil him on his special day, there are many other things that families can d...

Faultless Journeys: Exploring the Benefits of Bus Charter Services in Brisbane

Brisbane is a city full of lights, diversity, change and colours. It is populated with cultural differences and multiple businesses that offer a bundle of opportunities for interaction. There are multiple places to visit and explore in cases wher...

Vehicle Emissions Star Rating using public data to inform consumer purchasing decisions

Global open data company Link Digital has used open source technology to develop a new Vehicle Emissions  Star Rating (VESR) website for the New South Wales Government to help drivers consider the efficiency and  environmental impact of their nex...