Nav: Home

Using 'fire to fight fire' to combat disease could make it worse, tests show

December 30, 2016

A treatment billed as a potential breakthrough in the fight against disease, including cancer, could back-fire and make the disease fitter and more damaging, new research has found.

Ground-breaking research has found that introducing 'friendlier' less-potent strains into a population of disease-causing microbes can lead to increased disease severity.

The surprise findings by a team of scientists at the University of Exeter has led to calls for urgent research into the implications of using 'fire to fight fire' to combat disease. The research shows that far from being a 'silver bullet' to weaken disease, the practice of introducing pacifist microbes into a host could make the aggressive pathogen stronger, which could hamper disease management.

Until now, introducing friendlier cousins, which do not cause severe disease, into a population of pathogens has been shown to reduce disease severity and damage to the infected host. It has been suggested that this approach could be an effective way of treating cancer, and research so far has proved effective and promising. For example, scientists have already produced encouraging results in the fight against Clostridium difficile infections that are so common in our hospitals.

But the University of Exeter scientists tested this strategy using a plant pathogen, and found the therapy could go dramatically wrong, with devastating consequences for the host plant.

A team lead by Professors Ivana Gudelj, a mathematical biologist and Nick Talbot, a plant disease specialist, investigated the devastating rice blast disease. They introduced a mixed population of the fungus that causes this disease into rice, where the mixture included an aggressive strain and a pacifist mutant. They expected that the overall disease severity would decrease because of the presence of the pacifist strain. However, they found the opposite. The rice plants succumbed to much more severe disease.

The Exeter University research, published in eLife, shows that the therapy can in some circumstances have the opposite effect, and that the way the pathogen will behave can be unpredictable, leading to more severe disease. The research highlights the need for these new strategies to be carefully tested before they are used therapeutically.

The scientists used cooperation theory and mathematical modelling to identify the reason for their surprising result. They found that in some circumstances pacifists "helped" aggressive microbes to be more efficient in utilising resources obtained from the host.

Professor Ivana Gudelj, who led the research, said: "Our study shows that a promising disease management strategy may not always be effective and indeed may have damaging unforeseen consequences. Importantly, our work also provides a foundation for the analysis of when, and why, this can happen. We find that the mechanisms driving our unexpected findings when treating rice blast infection are pertinent for many diseases involving bacterial and fungal pathogens"

Developing new ways of treating infectious disease has become more pressing with the development of resistance to antibiotics.

One strategy being explored to treat infections that resist current drugs involves neutralising the disease-causing agent. This strategy involves extracting the agent from the patient so that scientists can remove components of the microbe's DNA in order to neutralise the disease.

This new harmless agent is then grown in the lab and re-introduced to the disease site with the expectation that it will out-compete its more harmful cousin by stealing resources the disease needs to proliferate. Such research has proved effective in several lab tests.

The University of Exeter scientists tested this method in rice blast infections, but found more severe disease symptoms.

Professor Nick Talbot, Professor of Molecular Genetics and expert in plant diseases, said: "The strategy of introducing less aggressive microbes to fight more aggressive ones may prove effective to control some crop disease, but our study shows that they are not a silver bullet and caution needs to be exercised. We need to understand how microbes interact with each other in natural settings, before we can try to alter their ability to cause disease in this way. Our study also shows why mathematicians and biologists need to work together more often, because we would not have understood this phenomenon at all without the mathematical analysis carried out."

Richard Lindsay, a PhD student who worked on the research team, added: "Our findings are of central importance in understanding how microbial infections evolve, but also have wider significance for the treatment of cancer and the therapeutic control of disease in humans, animals and plants."
-end-


University of Exeter

Related Cancer Articles:

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.
Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.
Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.
Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.
More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.
New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.
American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.
Oncotarget: Cancer pioneer employs physics to approach cancer in last research article
In the cover article of Tuesday's issue of Oncotarget, James Frost, MD, PhD, Kenneth Pienta, MD, and the late Donald Coffey, Ph.D., use a theory of physical and biophysical symmetry to derive a new conceptualization of cancer.
Health indicators for newborns of breast cancer survivors may vary by cancer type
In a study published in the International Journal of Cancer, researchers from the UNC Lineberger Comprehensive Cancer Center analyzed health indicators for children born to young breast cancer survivors in North Carolina.
Few women with history of breast cancer and ovarian cancer take a recommended genetic test
More than 80 percent of women living with a history of breast or ovarian cancer at high-risk of having a gene mutation have never taken the test that can detect it.
More Cancer News and Cancer Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.