Though only in early stages, findings could lead to a ‘therapeutic against current and newly-arising variants,’ say researchers
As SARS-CoV-2 changes and mutates, some therapeutic antibodies that were once highly effective in fighting the virus have lost potency. But now, in a proof-of-concept study, researchers from Boston Children’s Hospital have identified one antibody that neutralizes all known variants of the coronavirus, including the omicron variant. Microbiologists and clinical laboratory managers will find this intriguing, as most medical labs perform serology testing for SARS-CoV-2 antibodies.
The new antibody appears to be robust. It triggers several other types of antibodies as part of the immune response. If validated by further research, this discovery, the researchers state, may lead to new vaccines, better therapies, and improved treatments for COVID-19.
“We hope that this humanized antibody will prove to be as effective at neutralizing SARS-CoV-2 in patients as it has proven to be thus far in preclinical evaluations,” said geneticist Frederick Alt, PhD, Director of the Program in Cellular and Molecular Medicine at Boston Children’s Hospital and one of the leaders of the research. Clinical laboratories that perform serology testing for COVID-19 will be intrigued by this new line of research. (Photo copyright: PR Newswire.)
SP1-77 Antibody Outperforms All Others at Neutralizing SARS-CoV-2
To conduct their research, the team used genetically modified mice that basically have built-in human immune systems. These mice were originally utilized for seeking out antibodies to HIV, another virus that tends to mutate. Their immune systems can mimic what human immune systems encounter when a viral invader attacks.
The scientists inserted two human gene segments into the mice, which quickly produced antibodies resembling those made by humans. The mice were then exposed to the SARS-CoV-2 spike protein from the original coronavirus strain. The scientists found that the mice produced nine different families of antibodies that could bind to the spike protein.
The researchers then tested the effectiveness of those antibodies and found that three of the nine antibody families strongly neutralized the original SARS-CoV-2 coronavirus. In addition, one of the antibody families—dubbed SP1-77—was much more powerful and could neutralize the Alpha, Beta, Gamma, Delta, and all known Omicron strains of the SARS-CoV-2 virus.
New Monoclonal Antibody Products and Vaccines
If their findings are validated through further research, SP1-77 “would have potential to be a therapeutic against current and newly-arising variants of concern” according to the Science Immunology study. It also could be useful as part of a cocktail containing other antibody treatments for COVID-19 variants.
“SP1-77 binds the spike protein at a site that so far has not been mutated in any variant, and it neutralizes these variants by a novel mechanism,” said Tomas Kirchhausen, PhD, Senior Investigator, Program in Cellular and Molecular Medicine at Boston Children’s Hospital and one of the authors of the study in a statement announcing the study findings. “These properties may contribute to its broad and potent activity,” he added.
“This is very early-stage proof-of-concept work to illustrate that broadly neutralizing antibodies can be generated using a mouse model,” Amesh Adalja, MD, an infectious disease expert and senior scholar at the Johns Hopkins Center for Health Security, told Prevention. “Such work, if replicated and expanded, could form the basis of new monoclonal antibody products as well as a vaccine.”
The researchers have applied for a patent for the SP1-77 antibody as well as the mouse model they used to create it. Studies on the antibody are ongoing and have only been performed on mice and not humans. The scientists intend to execute further research on the innovative antibody and hope it will someday be used to help fight the COVID-19 virus and all its variants.
“We’d love to have a vaccine that is active against all circulating variants, including those yet to come,” Thomas Russo, MD, Professor and Chief of Infectious Disease, Department of Medicine, University at Buffalo told Prevention. “It’s the holy grail of vaccines.”
Microbiologists and clinical laboratories working with monoclonal antibodies to treat for COVID-19 infections will no doubt want to follow the Boston Children’s Hospital research closely as it may lead to new treatments and vaccines.
Researchers surprised that process designed to detect SARS-CoV-2 also identifies monkeypox in wastewater
Early information about an outbreak in a geographical region can inform local clinical laboratories as to which infectious agents and variants they are likely to see when testing patients who have symptoms. To that end, wastewater testing has become a rich source of early clues as to where COVID-19 outbreaks are spreading and how new variants of the coronavirus are emerging.
Ongoing advances in genetic sequencing and digital technologies are making it feasible to test wastewater for infectious agents in ways that were once too time-consuming, too expensive, or simply impossible.
“Before wastewater sequencing, the only way to do this was through clinical testing, which is not feasible at large scale, especially in areas with limited resources, public participation, or the capacity to do sufficient testing and sequencing,” said Knight in a UCSD press release. “We’ve shown that wastewater sequencing can successfully track regional infection dynamics with fewer limitations and biases than clinical testing to the benefit of almost any community.” (Photo copyright: UC San Diego News.)
Same Process, Different Virus
Following August’s declaration of a state of emergency by California, San Diego County, and the federal government, UCSD researchers added monkeypox surveillance to UCSD’s existing wastewater surveillance program.
“It’s the same process as SARS-CoV-2 qPCR monitoring, except that we have been testing for a different virus. Monkeypox is a DNA virus, so it is a bit of a surprise that our process optimized for SARS-CoV-2, which is an RNA virus, works so well,” said Rob Knight, PhD, Professor of Pediatrics and Computer Science and Engineering at UCSD and one of the lead authors of the study in the press release.
According to the press release, RNA sequencing from wastewater has two specific benefits:
It avoids the potential of clinical testing biases, and
It can track changes in the prevalence of SARS-CoV-2 variants over time.
In 2020, at the height of the COVID-19 pandemic, scientists from the University of California San Diego and Scripps Research looked into genetic sequencing of wastewater. They wanted to see if it would provide insights into levels and variants of the SARS-CoV-2 within a specific community.
Individuals who have COVID-19 shed the virus in their stool.
The UCSD/Scripps researchers deployed commercial auto-sampling robots to collect wastewater samples at the main UCSD campus. They analyzed the samples for levels of SARS-CoV-2 RNA at the Expedited COVID-19 Identification Environment (EXCITE) lab at UCSD. After the success of the program on the campus, they extended their research to include other facilities and communities in the San Diego area.
“The coronavirus will continue to spread and evolve, which makes it imperative for public health that we detect new variants early enough to mitigate consequences,” said Knight in a July press release announcing the publication of their study in the journal Nature, titled, “Wastewater Sequencing Reveals Early Cryptic SARS-CoV-2 Variant Transmission.”
Detecting Pathogens Weeks Earlier than Traditional Clinical Laboratory Testing
In July, the scientists successfully determined the genetic mixture of SARS-CoV-2 variants present in wastewater samples by examining just two teaspoons of raw sewage. They found they could accurately identify new variants 14 days before traditional clinical laboratory testing. They detected the presence of the Omicron variant 11 days before it was first reported clinically in the community.
During the study, the team collected and analyzed 21,383 sewage samples, with most of those samples (19,944) being taken from the UCSD campus. They performed genomic sequencing on 600 of the samples and compared them to genomes obtained from clinical swabs. They also compared 31,149 genomes from clinical genomic surveillance to 837 wastewater samples taken from the community.
The scientists distinguished specific viral lineages present in the samples by sequencing the viruses’ complete set of genetic instructions. Mutational differences between the various SARS-CoV-2 variants can be minute and subtle, but also have notable biological deviations.
“Nothing like this had been done before. Sampling and detection efforts began modestly but grew steadily with increased research capacity and experience. Currently, we’re monitoring almost 350 buildings on campus,” said UCSD’s Chancellor Pradeep Khosla, PhD, in the July press release.
“The wastewater program was an essential element of UC San Diego Health’s response to the COVID pandemic,” said Robert Schooley, MD, Infectious Disease Specialist at UC San Diego Health, in the press release. Schooley is also a professor at UCSD School of Medicine, and one of the authors of the study.
“It provided us with real-time intelligence about locations on campus where virus activity was ongoing,” he added. “Wastewater sampling essentially allowed us to ‘swab the noses’ of every person upstream from the collector every day and to use that information to concentrate viral detection efforts at the individual level.”
Monkeypox Added to UCSD Wastewater Surveillance
In August, UCSD officially added the surveillance of the monkeypox virus to their ongoing wastewater surveillance program. A month earlier, the researchers had discerned 10,565.54 viral copies per liter of wastewater. They observed the levels fluctuating and increasing.
On August 2, the scientists detected 189,309.81 viral copies per liter of wastewater. However, it is not yet clear if the monitoring of monkeypox viral loads in wastewater will enable the researchers to accurately predict future infections or case rates.
“We don’t yet know if the data will anticipate case surges like with COVID,” Knight said in the August UCSD press release announcing the addition of monkeypox to the surveillance program. “It depends on when the virus is shed from the body relative to how bad the symptoms are that cause people to seek care. This is, in principle, different for each virus, although in practice wastewater seems to be predictive for multiple viruses.”
Utilization of genetic sequencing of wastewater sampling will continue to develop and improve. “It’s fairly easy to add new pathogens to the process,” said Smruthi Karthikeyan, PhD, an environmental engineer and postdoctoral researcher in Knight’s lab who has overseen wastewater monitoring at UC San Diego. “It’s doable on short notice. We can get more information in the same turnaround time.”
Thus, clinical laboratories engaged in testing programs for COVID-19 may soon see the addition of monkeypox to those processes.
Viral reservoir could be behind persistence, says study, which also suggests a blood biomarker could be found for clinical laboratory testing
Microbiologists and virologists working closely with physicians treating long COVID-19 patients will gain new insights in a study that found coronavirus spike protein in COVID-19 patients’ blood up to 12 months after diagnosis. The researchers believe their findings could be used to develop a clinical laboratory biomarker for long COVID-19.
Researchers at Brigham and Women’s Hospital and Massachusetts General Hospital said medical experts are not sure why some people have unwelcome symptoms weeks and months after a positive COVID-19 diagnosis, while others clear the infection without lingering effects.
The scientists believe if this work is validated, clinical laboratories might gain an assay to use in the diagnosis of long COVID-19.
“The half-life of spike protein in the body is pretty short, so its presence indicates that there must be some kind of active viral reservoir,” said David Walt, PhD (above), Professor of Pathology, Brigham and Women’s Hospital, and lead author of the study that found coronavirus spike protein in long COVID patients. The study findings indicate a potential clinical laboratory biomarker for long COVID-19. (Photo copyright: Brigham and Women’s Hospital.)
Viral Reservoir Possibly Behind Long COVID-19
The study suggests that SARS-CoV-2 finds a home in the body, particularly the gastrointestinal tract, “through viral reservoirs, where it continues to release spike protein and trigger inflammation,” Medical News Today reported.
Lead author of the study David Walt, PhD, Professor of Pathology, Brigham and Women’s Hospital and the Hansjörg Wyss Professor Biologically Inspired Engineering at Harvard Medical School, told The Guardian he “was motivated to carry out the study after earlier research by his colleagues detected genetic material from the COVID virus (viral RNA) in stool samples from children with multisystem inflammatory syndrome (a rare but serious condition that often strikes around four weeks after catching COVID) as well as spike protein and a marker of gut leakiness in their blood.”
Long COVID—also known as long-haul COVID, post-COVID-19, or its technical name, post-acute sequelae of COVID-19 or PASC—can involve health problems continuing weeks, months, or even years after a positive diagnosis, according to the federal Centers for Disease Control and Prevention (CDC).
Symptoms of long COVID, according to the researchers, include:
fatigue,
loss of smell,
memory loss,
gastrointestinal distress, and
shortness of breath.
“If someone could somehow get to that viral load and eliminate it, it might lead to resolution of symptoms,” Walt told the Boston Globe, which noted that the researchers may explore a clinical trial involving antiviral drugs for treatment of long COVID-19.
Clues from Earlier Studies on Long COVID-19
Medical conditions that persisted following a COVID-19 infection have been studied for some time. In fact, in an earlier study, Walt and others found children who developed a multisystem inflammation syndrome weeks after being infected by SARS-CoV-2, according to their 2021 paper published in The Journal of Clinical Investigation, titled, “Multisystem Inflammatory Syndrome in Children Is Driven by Zonulin-Dependent Loss of Gut Mucosal Barrier.”
Although these earlier studies provided clues, the cause of PASC remains unclear, the researchers noted. They planned to take a more precise look at PASC biology by using appropriate sampling and patient recruitment.
“Disentangling the complex biology of PASC will rely on the identification of biomarkers that enable classification of patient phenotypes. Here, we analyze plasma samples collected from PASC and COVID-19 patients to determine the levels of SARS-CoV-2 antigens and cytokines and identify a blood biomarker that appears in the majority of PASC patients,” the researchers wrote.
Finding a Marker of a Persistent Infection
The researchers used plasma samples from 63 people with a previous SARS-CoV-2 diagnosis (37 also had PASC), Medical News Today reported. Over a 12-month period, the researchers’ findings included:
Detection in 65% of PASC samples of full-length spike, S1 spike, and nucleocapsid throughout the year of testing.
Spike detected in 60% of PASC patient samples, and not found in the COVID-19 samples.
In an interview with Scientific American, bioengineer Zoe Swank PhD, post-doctoral researcher, Brigham and Women’s Hospital, and co-author of the study, said, “Our main hypothesis is that the spike protein is not causing the symptoms, but it’s just a marker that is released because you still have infection of some cells with SARS-CoV-2.”
In that article, Swank shared the scientists’ intent to do more research involving hundreds of samples over the course of the COVID-19 pandemic from many hospitals and people.
COVID-19 Not the Only Virus That Hangs On
Having a long-haul COVID-19 marker is a “game-changer,” according to an infectious disease expert who was not involved in the study.
“There has not so far been a clear, objective marker that is measurable in the blood of people experiencing long COVID-19,” Michael Peluso, MD, Assistant Professor, Medicine, University of California San Francisco, told Scientific American. “I hope their findings will hold up. It really would make a difference for a lot of people if a marker like this could be validated,” he added.
However, COVID-19 is not the only virus that could persist. Ebola also may linger in areas that skirt the immune system, such as the eye interior and central nervous system, according to a World Health Organization fact sheet.
Thus, medical laboratory leaders may want to follow the Brigham and Women’s Hospital research to see if the scientists validate their finding, discover a biomarker for long-haul COVID-19, and pursue a clinical trial for antiviral drugs. Such discoveries could have implications for how diagnostic professionals work with physicians to care for long COVID patients.
Experts say it is time ‘to restore our confidence in vaccines’ as many medical laboratories take steps to support testing for the polio virus
Clinical laboratories and microbiologists in the state of New York will want to know that, in July, a man in New York was diagnosed with polio and subsequently the virus was detected in the wastewater of two New York counties.
The area, Rockland County, N.Y., just north of New York City, was also at the forefront of a measles outbreak that occurred in 2018 and 2019. The outbreak was attributed to low vaccination rates within the community.
The unidentified, immunocompetent young man was admitted to a New York hospital after experiencing a low-grade fever, neck stiffness, back and abdominal pain, constipation, and lower extremity weakness. He eventually developed paralysis from the disease, which is irreversible.
Poliomyelitis, commonly known as polio, is a disabling and life-threatening disease that is caused by the poliovirus. Though it rarely surfaces in the United States, there is now confirmation of the first US case since 2013.
“The polio vaccine is safe and effective, protecting against this potentially debilitating disease, and it has been part of the backbone of required, routine childhood immunizations recommended by health officials and public health agencies nationwide,” said Mary T. Bassett, MD (left), Health Commissioner at the New York Department of Health, in a press release. Clinical laboratories and microbiologists in New York may want to prepare for an increase in vaccination requests. (Photo copyright: Time.)
Is Polio Back in America? Clinical Laboratories Will Want to Be Prepared
“I think it’s concerning because it can spread,” epidemiologist Walter Orenstein, MD, Professor, Department of Medicine, Division of Infectious Diseases at Emory University School of Medicine told STAT. “If there are unvaccinated communities, it can cause a polio outbreak.”
According to the federal Centers for Disease Control and Prevention (CDC), public health experts are working diligently to discover how and where the infected individual contracted polio. The CDC website states that the risk for people who have received the polio vaccine is very low, but there is concern for those who have not received the recommended doses of the vaccine.
“Most of the US population has protection against polio because they were vaccinated during childhood, but in some communities with low vaccine coverage, there are unvaccinated people at risk,” the CDC noted. “Polio and its neurologic effects cannot be cured but can be prevented through vaccination.”
The US uses an injectable polio vaccine for the poliovirus which contains killed viruses. The vaccine “instructs” the immune system to recognize and combat the virus. This inactivated polio vaccine (IPV) is administered to children as a shot in the arm or leg and is typically given in four separate doses.
“The inactivated polio vaccine we have is very effective and very safe and could have prevented this,” Orenstein told STAT. “We need to restore our confidence in vaccines.”
“Based on what we know about this case, and polio in general, the (New York) Department of Health strongly recommends that unvaccinated individuals get vaccinated or boosted with the FDA-approved IPV polio vaccine as soon as possible,” said Mary T. Bassett, MD, Health Commissioner at the New York Department of Health in a press release.
Poliovirus Found in Wastewater via Use of Gene Sequencing
Poliovirus is very contagious and is transmitted through person-to-person contact. The virus lives in an infected person’s throat and intestines and can contaminate food and water in unsanitary conditions. According to the CDC, typical symptoms of the illness include flu-like symptoms such as:
Sore throat
Fever
Tiredness
Nausea
Headache
Stomach pain
Most of these symptoms will disappear within five days, but polio can invade the nervous system and cause more serious complications, such as meningitis, paralysis, and even death.
After confirmation of the new case of polio, wastewater surveillance detected the presence of the poliovirus in Rockland and Orange counties, New York.
Wastewater analysis can uncover pathogens within a community and has been used in the fight against other infectious diseases, including:
“In some regards, wastewater is a public health dream scenario,” said Mark Siedner, MD, an infectious disease doctor at Massachusetts General Hospital and associate professor at Harvard Medical School, in an interview with Fortune. “Everyone poops, and most people poop every day. It provides real-time data on infection rates. In that regard, it’s an extremely powerful tool, particularly good at detecting early warning signs. Before people get sick, we might get a signal.”
Wastewater analysis can provide insights regarding the types of viruses that people within a community are shedding and if the volume of those viruses are increasing. This information can provide scientists with an early marker for an outbreak of an illness that is on the verge of spreading.
Microbiologists and clinical laboratories should be aware of the specific types of infectious agents public health authorities are detecting in wastewater, even as they perform screening and diagnostic tests on their patients for similar infectious diseases.
Polio is Appearing Worldwide
The Global Polio Eradication Initiative (GPEI) has announced that new cases of polio have been reported in Israel and the United Kingdom. These are countries where polio cases are extremely rare.
This indicates that microbiologists and clinical laboratories managers will want to be on constant alert for uncommon infectious diseases that may appear suddenly, even if those illnesses are rare. Accurate and immediate diagnoses of such infectious diseases could play a major role in triggering a public health response to control potential outbreaks while they are in their earlier stages.
Clinical laboratories continue to report positive COVID-19 tests for individuals that have been vaccinated and even previously infected with the same variant of the coronavirus
Researchers across the globe continue to study the SARS-CoV-2 coronavirus and its many variants. Their goals are to curb the spread of the disease and develop new therapies and treatments for optimal patient outcomes. Now, a study conducted by scientists at the University of Missouri (UM) provides deeper insight into the processes the virus uses to mutate and overpower the human immune system. These findings could lead to improved antivirals and clinical laboratory tests for COVID-19.
The UM team identified specific mutations occurring within the virus’ spike protein that help Omicron subvariants evade existing antibodies and create an infection. These mutations may explain why some people who have had previous COVID-19 infections and/or who are fully vaccinated continue to test positive for SARS-CoV-2, and why the virus continues to evolve.
“Omicron now has more than 130 sublineages and they have been here for quite a while. We are now just finally able to detect them and differentiate among them with this research,” said Kamlendra Singh, PhD, associate research professor in the Department of Veterinary Pathobiology at UM’s College of Veterinary Medicine, in a UM press release.
“Previous variants, including Alpha, Beta, Gamma, and Delta, contributed to many of the mutations occurring now with these Omicron variants. So, our research shows how the virus has evolved over time with new mutations,” he added.
“Throughout the pandemic, the [SARS-CoV-2] virus has continued to get smarter and smarter. Even with vaccines, it continues to find new ways to mutate and evade existing antibodies,” said Kamlendra Singh, PhD (above), Associate Research Professor, College of Veterinary Medicine at University of Missouri, in a UM press release. This research team’s findings may help clinical laboratories further develop their SARS-CoV-2 antibody tests. (Photo copyright: University of Missouri.)
Antibodies for One Variant, but Not for Another
The scientists began their investigation by researching online databases that track COVID-19 cases and analyzing the protein sequences from more than 10 million Omicron-related samples that were collected from around the world since November of last year.
They examined the available sequences, structures of spike/receptor and spike/antibody complexes of the samples, and then conducted molecular dynamics simulations. The team utilized 3D modeling to locate where mutations occur and created structures of the spike protein to determine how the mutations are affected by antibodies and vaccinations.
The researchers found that the Omicron variant continues to mutate and has become extremely efficient at adaptation. Reinfections are happening because many individuals do not possess the antibodies for the new subvariants that continue to develop.
“Vaccinated individuals, or those who have previously tested positive, may have the antibodies for one variant but not necessarily for any of the other variants,” Singh explained. “The various mutations may seem like only subtle differences, but they are very important.”
The UM scientists’ research shows it is possible to differentiate Omicron subvariants from each other and pinpoint how certain mutations might become problematic for patients. According to Singh, many people can be infected with multiple variants at the same time. He is hopeful that their work will make it possible for vaccines and other treatments to specifically target different strains of the virus.
Singh also believes that the coronavirus is most likely never going to disappear from society and that new variants and their sublineages will continue to appear and evolve.
“The ultimate solution going forward will likely be the development of small molecule, antiviral drugs that target parts of the virus that do not mutate,” Singh said. “While there is no vaccine for HIV, there are very effective antiviral drugs that help those infected live a healthy life, so hopefully the same can be true with COVID-19.”
Omicron Subvariants May Be Here to Stay
“I am proud of my team’s efforts, as we have identified specific mutations for various variants throughout the pandemic, and it feels good to be contributing to research that is assisting with the situation,” Singh said. “We will continue to help out, as there will surely be new variants in the future.”
Singh is also part of a team that developed a supplement called CoroQuil-Zn, which was designed to reduce a patient’s viral load after being infected with SARS-CoV-2. The drug is currently being used in parts of India and is awaiting approval from the US Food and Drug Administration (FDA).
Clinical laboratories that perform antibody testing for SARS-CoV-2 infections should be aware that the coronavirus will likely be moving among humans for many years to come. This recent research may aid in the development of new antivirals, treatments, and vaccines that target specific subvariants for the best patient outcomes.
Understanding why some mutations impair normal bodily functions and contribute to cancer may lead to new clinical laboratory diagnostics
New insight into the human genome may help explain the ageing process and provide clues to improving human longevity that can be useful to clinical laboratories and researchers developing cancer diagnostics. A recent study conducted at the Wellcome Sanger Institute in Cambridge, United Kingdom, suggests that the speed of DNA errors in genetic mutations may play a critical role in the lifespan and survival of a species.
To perform their research, the scientists analyzed genomes from the intestines of 16 mammalian species looking for genetic changes. Known as somatic mutations, these mutations are a natural process that occur in all cells during the life of an organism and are typically harmless. However, some somatic mutations can impair the normal function of a cell and even play a role in causing cancer.
“Aging is a complex process, the result of multiple forms of molecular damage in our cells and tissues. Somatic mutations have been speculated to contribute to ageing since the 1950s, but studying them had remained difficult,” said Inigo Martincorena, PhD (above), Group Leader, Sanger Institute and one of the authors of the study. Greater understanding of the role DNA mutations play in cancer could lead to new clinical laboratory tools and diagnostics. (Photo copyright: Wellcome Sanger Institute.)
Lifespans versus Body Mass
The mammalian subjects examined in the study incorporated a wide range of lifespans and body masses and included humans, giraffes, tigers, mice, and the highly cancer-resistant naked mole-rat. The average number of somatic mutations at the end of a lifespan was around 3,200 for all the species studied, despite vast differences in age and body mass. It appears that species with longer lifespans can slow down their rate of genetic mutations.
The average lifespan of the humans used for the study was 83.6 years and they had a somatic mutation rate of 47 per year. Mice examined for the research endured 796 of the mutations annually and only lived for 3.7 years.
Species with similar amounts of the mutations had comparable lifespans. For example, the small, naked mole-rats analyzed experienced 93 mutations per year and lived to be 25 years of age. On the other hand, much larger giraffes encountered 99 mutations each year and had a lifespan of 24 years.
“With the recent advances in DNA sequencing technologies, we can finally investigate the roles that somatic mutations play in ageing and in multiple diseases,” said Inigo Martincorena, PhD, Group Leader, Sanger Institute, one of the authors of the study in a press release. He added, “That this diverse range of mammals end their lives with a similar number of mutations in their cells is an exciting and intriguing discovery.”
The scientists analyzed the patterns of the mutations and found that the somatic mutations accumulated linearly over time. They also discovered that the mutations were caused by similar mechanisms and the number acquired were relatively similar across all the species, despite a difference in diet and life histories. For example, a giraffe is typically 40,000 times larger than a mouse, but both species accumulate a similar number of somatic mutations during their lifetimes.
“The fact that differences in somatic mutation rate seem to be explained by differences in lifespan, rather than body size, suggests that although adjusting the mutation rate sounds like an elegant way of controlling the incidence of cancer across species, evolution has not actually chosen this path,” said Adrian Baez-Ortega, PhD, postdoctoral researcher at the Sanger Institute and one of the paper’s authors, in the press release.
“It is quite possible that every time a species evolves a larger size than its ancestors—as in giraffes, elephants, and whales—evolution might come up with a different solution to this problem. We will need to study these species in greater detail to find out,” he speculated.
Why Some Species Live Longer than Others
The researchers also found that the rate of somatic mutations decreased as the lifespan of each species increased which suggests the mutations have a likely role in ageing. It appears that humans and animals perish after accumulating a similar number of these genetic mutations which implies that the speed of the mutations is vital in ascertaining lifespan and could explain why some species live substantially longer than others.
“To find a similar pattern of genetic changes in animals as different from one another as a mouse and a tiger was surprising. But the most exciting aspect of the study has to be finding that lifespan is inversely proportional to the somatic mutation rate,” said Alex Cagan, PhD, Postdoctoral Fellow at the Sanger Institute and one of the authors of the study in the press release.
“This suggests that somatic mutations may play a role in ageing, although alternative explanations may be possible. Over the next few years, it will be fascinating to extend these studies into even more diverse species, such as insects or plants,” he noted.
Benefit of Understanding Ageing and Death
The scientists believe this study may provide insight to understanding the ageing process and the inevitability and timing of death. They surmise that ageing is likely to be caused by the aggregation of multiple types of damage to the cells and tissues suffered throughout a lifetime, including somatic mutations.
Some companies that offer genetic tests claim their products can predict longevity, despite the lack of widely accepted evidence that such tests are accurate within an acceptable range. Further research is needed to confirm that the findings of the Wellcome Sanger Institute study are relevant to understand the ageing process.
If the results are validated, though, it is probable that new direct-to-consumer (DTC) genetic tests will be developed, which could be a new revenue source for clinical laboratories.
