. Scientific Frontline: Biology
Showing posts with label Biology. Show all posts
Showing posts with label Biology. Show all posts

Thursday, April 4, 2024

New sunflower family tree reveals multiple origins of flower symmetry

A new sunflower family tree reveals that flower symmetry evolved multiple times independently. Chrysanthemum lavandulifolium, on the upper left, and Artemisia annua, upper right, are closely related species from the same tribe; the former has bilaterally symmetric flowers — the rays — and the latter does not. Rudbeckia hirta, lower left, from the sunflower tribe has bilaterally symmetric flowers, and Eupatorium chinense, lower right, from the Eupatorieae tribe does not; these two tribes are closely related groups. A sunflower, center, shows flowers with bilateral symmetry — the large petal-like flowers in the outer row — and without bilateral symmetry — the small flowers in the inner rows.
Photo Credits: Guojin Zhang, Ma laboratory / Pennsylvania State University

The sunflower family tree revealed that flower symmetry evolved multiple times independently, a process called convergent evolution, among the members of this large plant family, according to a new analysis. The research team, led by a Penn State biologist, resolved more of the finer branches of the family tree, providing insight into how the sunflower family — which includes asters, daisies and food crops like lettuce and artichoke — evolved.

A paper describing the analysis and findings, which researchers said may help identify useful traits to selectively breed plants with more desirable characteristics is available online and will be published in an upcoming print edition of the journal Plant Communications.

“Convergent evolution describes the independent evolution of what appears to be the same trait in different species, like wings in birds and bats,” said Hong Ma, Huck Chair in Plant Reproductive Development and Evolution, professor of biology in the Eberly College of Science at Penn State and the leader of the research team. “This can make it difficult to determine how closely related two species are by comparing their traits, so having a detailed family tree based on DNA sequence is crucial to understanding how and when these traits evolved.”

Scientists identify rare gene variants which confer up to 6-fold increase in risk of obesity

Photo Credit: Mart Production

The discovery of rare variants in the genes BSN and APBA1 are some of the first obesity-related genes identified for which the increased risk of obesity is not observed until adulthood.

The study, published in Nature Genetics, was led by researchers at the Medical Research Council (MRC) Epidemiology Unit and the MRC Metabolic Diseases Unit at the Institute of Metabolic Science, both based at the University of Cambridge.

The researchers used UK Biobank and other data to perform whole exome sequencing of body mass index (BMI) in over 500,000 individuals.

They found that genetic variants in the gene BSN, also known as Bassoon, can raise the risk of obesity as much as six times and was also associated with an increased risk of non-alcoholic fatty liver disease and of type 2 diabetes.

The Bassoon gene variants were found to affect 1 in 6,500 adults, so could affect about 10,000 people in the UK.

Wednesday, April 3, 2024

Discovery of how COVID-19 virus replicates opens door to new antiviral therapies

A new study, looking at the replication stage of the SARS-CoV-2 virus that causes COVID-19, discovered important mechanisms in its replication that could be the foundation for new antiviral therapies.
Image Credit: Gerd Altmann

The study, which sets out to investigate how the SARS-CoV-2 virus replicates once it enters the cells, has made surprising discoveries that could be the foundation for future antiviral therapies. It also has important theoretical implications as the replication of the SARS-CoV-2 virus has, so far, received less attention from researchers.

The viral life cycle can be broken down into two main stages: the first stage is where the virus enters the cell. The second stage is replication where the virus uses the molecular machinery of the cell it has infected to replicate itself by building its parts, assembling them into new viruses that can then exit to infect other cells.

The majority of research into SARS-CoV-2 – the causative agent of COVID-19 – has focused on the Spike protein that allows viral entry. This has led to a lack of understanding of how the virus replicates once it has entered the cell.

A new paper led by Dr Jeremy Carlton in collaboration with Dr David Bauer at the Francis Crick Institute, focuses on how the Envelope protein of SARS-CoV-2 controls late stages of viral replication.

Pressure determines which embryonic cells become ‘organizers’

 Tooth epithelium (cell surface; yellow) and mesenchyme (cell surface; magenta). Proliferating cells (cyan) expand the tissue, generating a mechanical pressure at the tissue center that drives the formation of the main tooth signaling center or organizer, the enamel knot.
Photo Credit Neha Pincha Shroff and Pengfei Xu

A collaboration between research groups at the University of California, TU Dresden in Germany and Cedars-Sinai Guerin Children’s in Los Angeles has identified a mechanism by which embryonic cells organize themselves to send signals to surrounding cells, telling them where to go and what to do. While these signaling centers have been known to science for a while, how individual cells turn into organizers has been something of a mystery.

Until now. In a paper published in the journal Nature Cell Biology, the researchers find that cells are literally pressed into becoming organizers.

“We were able to use microdroplet techniques to figure out how the buildup of mechanical pressure affects organ formation,” said co-corresponding author Otger Campàs, former associate professor of mechanical engineering at UC Santa Barbara, who is currently managing director, professor and chair of tissue dynamics at the Physics of Life Excellence Cluster of TU Dresden.

Discovery could end global amphibian pandemic

Panamanian golden frog
Photo Credit: Brian Gratwicke/U.S. Fish & Wildlife Service

A fungus devastating frogs and toads on nearly every continent may have an Achilles heel. Scientists have discovered a virus that infects the fungus, and that could be engineered to save the amphibians.

The fungus, Batrachochytrium dendrobatidis or Bd, ravages the skin of frogs and toads, and eventually causes heart failure. To date it has contributed to the decline of over 500 amphibian species, and 90 possible extinctions including yellow-legged mountain frogs in the Sierras and the Panamanian golden frog. 

A new paper in the journal Current Biology documents the discovery of a virus that infects Bd, and which could be engineered to control the fungal disease.

The UC Riverside researchers who found the virus are excited about the implications of their discovery. In addition to helping them learn about how fungal pathogens rise and spread, it offers the hope of ending what they call a global amphibian pandemic. 

“Frogs control bad insects, crop pests, and mosquitoes. If their populations all over the world collapse, it could be devastating,” said UCR microbiology doctoral student and paper author Mark Yacoub. 

“They’re also the canary in the coal mine of climate change. As temperatures get warmer, UV light gets stronger, and water quality gets worse, frogs respond to that. If they get wiped out, we lose an important environmental signal,” Yacoub said. 

In the evolution of walking, the hip bone connected to the rib bones

New reconstruction of the skeleton of Tiktaalik roseae, a 375-million-year-old fossil fish. In a new study, researchers used micro-CT imaging to reveal vertebrae and ribs of the fish that were previously hidden beneath rock. The new reconstruction shows that the fish’s ribs likely attached to its pelvis, an innovation thought to be crucial to supporting the body and for the eventual evolution of walking.
Photo Credit: Thomas Stewart / Pennsylvania State University

Before the evolution of legs from fins, the axial skeleton — including the bones of the head, neck, back and ribs — was already going through changes that would eventually help our ancestors support their bodies to walk on land. A research team including a Penn State biologist completed a new reconstruction of the skeleton of Tiktaalik, the 375-million-year-old fossil fish that is one of the closest relatives to limbed vertebrates. The new reconstruction shows that the fish’s ribs were likely attached to its pelvis, an innovation thought to be crucial to supporting the body and for the eventual evolution of walking.

A paper describing the new reconstruction, which used microcomputed tomography (micro-CT) to scan the fossil and reveal vertebrae and ribs of the fish that were previously hidden beneath rock, appeared in the journal Proceedings of the National Academy of Sciences.

“Tiktaalik was discovered in 2004, but key parts of its skeleton were unknown,” said Tom Stewart, assistant professor of biology in the Eberly College of Science at Penn State and one of the leaders of the research team. “These new high-resolution micro-CT scans show us the vertebrae and ribs of Tiktaalik and allow us to make a full reconstruction of its skeleton, which is vital to understanding how it moved through the world.”

Tuesday, April 2, 2024

Scientists link certain gut bacteria to lower heart disease risk

Rod-shaped Oscillibacter sp. bacteria take up fluorescently labeled cholesterol (here shown in green).
Image Credit: Ahmed Mohamed 

Changes in the gut microbiome have been implicated in a range of diseases including type 2 diabetes, obesity, and inflammatory bowel disease. Now, a team of researchers at the Broad Institute of MIT and Harvard along with Massachusetts General Hospital has found that microbes in the gut may affect cardiovascular disease as well. In a study published in Cell, the team has identified specific species of bacteria that consume cholesterol in the gut and may help lower cholesterol and heart disease risk in people.

Members of Ramnik Xavier’s lab, Broad’s Metabolomics Platform, and collaborators analyzed metabolites and microbial genomes from more than 1,400 participants in the Framingham Heart Study, a decades-long project focused on risk factors for cardiovascular disease. The team discovered that bacteria called Oscillibacter take up and metabolize cholesterol from their surroundings, and that people carrying higher levels of the microbe in their gut had lower levels of cholesterol. They also identified the mechanism the bacteria likely use to break down cholesterol. The results suggest that interventions that manipulate the microbiome in specific ways could one day help decrease cholesterol in people. The findings also lay the groundwork for more targeted investigations of how changes to the microbiome affect health and disease.

“Our research integrates findings from human subjects with experimental validation to ensure we achieve actionable mechanistic insight that will serve as starting points to improve cardiovascular health,” said Xavier, who is a core institute member, director of the Immunology Program, and co-director of the Infectious Disease and Microbiome Program at the Broad. He is also a professor at Harvard Medical School and Massachusetts General Hospital.

Sunday, March 31, 2024

Rice biologists uncover new species of tiger beetle: Eunota houstoniana

Eunota houstoniana, with male on left and female on right.
Photo Credit: Rice University

Rice University evolutionary biologist Scott Egan and his research team have unearthed a new species of tiger beetle, deemed Eunota houstoniana, honoring the Houston region where it predominantly resides.

The team employed cutting-edge genetic sequencing technology alongside traditional measurements of their physical appearance and geographic range data to redefine species boundaries within the Eunota circumpicta species complex. This approach, known as integrative taxonomy, allowed them to identify distinct biological entities previously overlooked.

The study is published online in Nature Scientific Reports.

“It is amazing that within the city limits of Houston, we still don’t know all the species of insects or plants we share our region with,” Egan said. “I’m always interested in learning more about the biodiversity of the Gulf Coast.”

The Eunota houstoniana was once considered synonymous with the more common Eunota circumpicta, but the team’s research revealed significant differences, emphasizing the need for a refined process to species delineation.

Eunota houstoniana exhibits distinct genetic and physical characteristics. It is slightly smaller in size, its metallic coloring is more subdued, and it has unique behavior and habitat preferences.

Scientists identify Achilles heel of lung cancer protein

Researchers have shown for the first time that a crucial interface in a protein that drives cancer growth could act as a target for more effective treatments.

The study, led by the Science and Technology Facilities Council (STFC) Central Laser Facility (CLF) with support from the Imaging Therapies and Cancer Group at King's, used advanced laser imaging techniques to identify structural details of a mutated protein which help it to evade drugs that target it.

The study was published in the journal Nature Communications and lays the groundwork for future research into more effective, long-lasting cancer therapies.

The Epidermal Growth Factor Receptor (EGFR) is a protein that sits on the surface of cells and receives molecular signals that tell the cell to grow and divide. In certain types of cancer, mutated EGFR stimulate uncontrolled growth, resulting in tumors.

Various cancer treatments block and inhibit mutant EGFR to prevent tumor formation, but these are limited as eventually cancerous cells commonly develop further EGFR mutations that are resistant to treatment.

Until now, how exactly these drug-resistant EGFR mutations drive tumor growth was not understood, hindering our ability to develop treatments that target them.

Saturday, March 30, 2024

Researchers discover molecule that promotes production of cancer cells in triple-negative breast cancer

Hiroshima University researchers found that AIbZIP is highly upregulated in triple negative breast cancer (TNBC). AIbZIP induces hyper proliferation of TNBC cells by promoting the degradation of p27, a negative regulator for cell proliferation.
Illustration Credit: Atsushi Saito/Hiroshima University

A team of researchers from Hiroshima University has discovered a molecule that promotes the production of cancer cells. This molecule may prove to be a potential therapeutic target in the treatment of triple-negative breast cancer, an aggressive form of breast cancer.

Breast cancer is the most common type of cancer, ranking fifth among all cancers in cancer-related deaths. In 2020, there were 2.3 million new cases of breast cancer reported around the globe. In that year, breast cancer caused 685,000 deaths.

Several studies have reported that a molecule called AIbZIP (androgen induced basic leucine zipper) promotes malignant behavior in different cancer types. So, the research team examined the potential role of AIbZIP in malignant tumors. Their computer simulation analysis revealed that AIbZIP was highly expressed in the luminal androgen receptor subtype of triple negative breast cancer, playing a significant role in cell cycle regulation. They identified a novel mechanism by which AIbZIP regulates cancer cell proliferation in this type of breast cancer.

“We found that AIbZIP is highly upregulated in triple negative breast cancer. AIbZIP plays a crucial role for hyper proliferation of triple negative breast cancer cells by promoting the degradation of p27, a negative regulator for cell proliferation. Our study indicates that AIbZIP may be potential therapeutic target of triple negative breast cancer” said Atsushi Saito, an associate professor and Kazunori Imaizumi, a professor in the Department of Biochemistry, Graduate School of Biomedical and Health Sciences, Hiroshima University.  

Friday, March 29, 2024

‘Exhausted’ immune cells in healthy women could be target for breast cancer prevention

Photo Credit: Angiola Harry

Everyone has BRCA1 and BRCA2 genes, but mutations in these genes - which can be inherited - increase the risk of breast and ovarian cancer.

The study found that the immune cells in breast tissue of healthy women carrying BRCA1 or BRCA2 gene mutations show signs of malfunction known as ‘exhaustion’. This suggests that the immune cells can’t clear out damaged breast cells, which can eventually develop into breast cancer.

This is the first time that ‘exhausted’ immune cells have been reported in non-cancerous breast tissues at such scale - normally these cells are only found in late-stage tumors.

The results raise the possibility of using existing immunotherapy drugs as early intervention to prevent breast cancer developing, in carriers of BRCA1 and BRCA2 gene mutations.

The researchers have received a ‘Biology to Prevention Award’ from Cancer Research UK to trial this preventative approach in mice. If effective, this will pave the way to a pilot clinical trial in women carrying BRCA gene mutations.

“Our results suggest that in carriers of BRCA mutations, the immune system is failing to kill off damaged breast cells - which in turn seem to be working to keep these immune cells at bay,” said Professor Walid Khaled in the University of Cambridge’s Department of Pharmacology and Wellcome-MRC Cambridge Stem Cell Institute, senior author of the report.

Risk factors for faster aging in the brain revealed in new study

Governments have been urged to act decisively before 2035 to ensure global warming can be kept below 2°C by 2100.
Photo Credit: Nöel Puebla

Researchers from the Nuffield Department of Clinical Neurosciences at the University of Oxford have used data from UK Biobank participants to reveal that diabetes, traffic-related air pollution and alcohol intake are the most harmful out of 15 modifiable risk factors for dementia.

The researchers had previously identified a ‘weak spot’ in the brain, which is a specific network of higher-order regions that not only develop later during adolescence, but also show earlier degeneration in old age. They showed that this brain network is also particularly vulnerable to schizophrenia and Alzheimer’s disease.

In this new study, published in Nature Communications, they investigated the genetic and modifiable influences on these fragile brain regions by looking at the brain scans of 40,000 UK Biobank participants aged over 45.

The researchers examined 161 risk factors for dementia, and ranked their impact on this vulnerable brain network, over and above the natural effects of age. They classified these so-called ‘modifiable’ risk factors − as they can potentially be changed throughout life to reduce the risk of dementia − into 15 broad categories: blood pressure, cholesterol, diabetes, weight, alcohol consumption, smoking, depressive mood, inflammation, pollution, hearing, sleep, socialization, diet, physical activity, and education.

Not unique to humans but uniquely human: researchers identify factor involved in brain expansion in humans

A microscopy image of a human brain organoid.
Image Credit: © Janine Hoffmann

What makes us human? According to neurobiologists it is our neocortex. This outer layer of the brain is rich in neurons and lets us do abstract thinking, create art, and speak complex languages. An international team led by Dr. Mareike Albert at the Center for Regenerative Therapies Dresden (CRTD) of TUD Dresden University of Technology has identified a new factor that might have contributed to neocortex expansion in humans. The results were published in the EMBO Journal.

The neocortex is the characteristic folded outer layer of the brain that resembles a walnut. It is responsible for higher cognitive functions such as abstract thinking, art, and language. “The neocortex is the most recently evolved part of the brain,” says Dr. Mareike Albert, research group leader at the CRTD. “All mammals have a neocortex, but it varies in size and complexity. Human and primate neocortices have folds while, for example, mice have a completely smooth neocortex, without any creases.”

The folds characteristic of the human brain increases the surface area of the neocortex. The human neocortex has a greater number of neurons that support complex cognitive functions.

The molecular mechanisms driving neocortex evolution are still largely unknown. “Which genes are responsible for inter-species differences in neocortex size? What factors have contributed to brain expansion in humans? Answering these questions is crucial to understanding human brain development and potentially addressing mental health disorders,” explains Dr. Albert.

Thursday, March 28, 2024

Researchers Identify Microbes That Help Plants Thwart Parasite

Sorghum crops in sub-Saharan Africa suffer heavy losses from the parasitic plant witchweed (Striga hermonthica). A new study shows how soil microbes can help protect sorghum from this pest and could be the basis for a soil probiotic treatment.
Photo Credit: Sabine

Bacteria that could help one of Africa’s staple crops resist a major pest have been identified by researchers at the University of California, Davis. Their findings, published in Cell Reports, could improve yields of sorghum, a mainstay of food and drink in West and East African countries.

About 20 percent of Africa’s sorghum crop is lost due to witchweed (Striga hermonthica), a parasitic plant that steals nutrients and water by latching onto the plant’s roots.

In a new study, UC Davis researchers show that soil microbes induce changes in sorghum roots that make the plant more resistant to infection by witchweed. They identified specific strains of bacteria that trigger these resistance traits and could be applied as a soil “probiotic” to improve sorghum yields in future.

“These microbes have great promise as soil additives that can help farmers grow sorghum successfully in sub-Saharan Africa,” said Siobhan Brady, a professor in the Department of Plant Biology and Genome Center and a senior author on the paper. 

Friday, March 22, 2024

Messenger RNAs with multiple “tails” could lead to more effective therapeutics

Graphic showing scientists adding "tails" to mRNA molecules
Illustration Credit: Catherine Boush, Broad Communications

Messenger RNA (mRNA) made its big leap into the public limelight during the pandemic, thanks to its cornerstone role in several COVID-19 vaccines. But mRNAs, which are genetic sequences that instruct the body to produce proteins, are also being developed as a new class of drugs. For mRNAs to have broad therapeutic uses, however, the molecules will need to last longer in the body than those that make up the COVID vaccines. 

Researchers from the Broad Institute of MIT and Harvard and MIT have engineered a new mRNA structure by adding multiple “tails” to the molecules that boosted mRNA activity levels in cells by 5 to 20 times. The team also showed that their multi-tailed mRNAs lasted 2 to 3 times longer in animals compared to unmodified mRNA, and when incorporated into a CRISPR gene-editing system, resulted in more efficient gene editing in mice. 

The new mRNAs, reported in Nature Biotechnology, could potentially be used to treat diseases that require long-lasting treatments that edit genes or replace faulty proteins. 

“The use of mRNA in COVID vaccines is fantastic, which prompted us to explore how we could expand the possible therapeutic applications for mRNA,” said Xiao Wang, senior author of the new paper, a core institute member at the Broad and an assistant professor of chemistry at MIT. “We’ve shown that non-natural structures can function so much better than naturally occurring ones. This research has given us a lot of confidence in our ability to modify mRNA molecules chemically and topologically.”

Two keys needed to crack three locks for better engineered blood vessels

Two proteins can trigger the signaling cascades needed to help differentiate stem cells into endothelial cells that can form tubular-like vessels in a dish, according to a team led by Penn State researchers. The finding has implications for developing drug-testing platforms and other clinical applications. 
Image Credit: Lian Lab / Pennsylvania State University

Blood vessels engineered from stem cells could help solve several research and clinical problems, from potentially providing a more comprehensive platform to screen if drug candidates can cross from the blood stream into the brain to developing lab-grown vascular tissue to support heart transplants, according to Penn State researchers. Led by Xiaojun “Lance” Lian, associate professor of biomedical engineering and of biology, the team discovered the specific molecular signals that can efficiently mature nascent stem cells into the endothelial cells that comprise the vessels and regulate exchanges to and from the blood stream.

They published their findings in Stem Cell Reports. The team already holds a patent on foundational method developed 10 years ago and has filed a provisional application for the expanded technology described in this paper.

The reserchers found they could achieve up to a 92% endothelial cell conversion rate by applying two proteins — SOX17 and FGF2 — to human pluripotent stem cells. This type of stem cell, which the researchers derived from a federally approved stem cell line, can differentiate into almost any other cell type if provided the right proteins or other biochemical signals. SOX17 and FGF2 engage three markers in stem cells, triggering a growth cascade that not only converts them to endothelial cells but also enables them to form tubular-like vessels in a dish.

Wednesday, March 20, 2024

Natural recycling at the origin of life

Volcanic freshwater lakes, similar to those found in Iceland today, offered a favorable niche on an early earth. The low-salt, alkaline conditions enabled early RNA replication.
Photo Credit: © Dieter Braun

How was complex life able to develop on the inhospitable early Earth? At the beginning there must have been ribonucleic acid (RNA) to carry the first genetic information. To build up complexity in their sequences, these biomolecules need to release water. On the early Earth, which was largely covered in seawater, that was not so easy to do. In a paper recently published in the Journal of the American Chemical Society (JACS), researchers from the team of LMU professor Dieter Braun have shown that in RNA’s struggle with the surrounding water, its natural recycling capabilities and the right ambient conditions could have been decisive.

“The building blocks of RNA release a water molecule for every bond they form in a growing RNA chain,” explains Braun, spokesperson for the Collaborative Research Centre (CRC) Molecular Evolution in Prebiotic Environments and coordinator at the ORIGINS Excellence Cluster. “When, conversely, water is added to an RNA molecule, the RNA building blocks are fed back into the prebiotic pool.” This turnover of water works particularly well under low saline conditions with high pH levels. “Our experiments indicate that life could emerge from a very small set of molecules, under conditions such as those prevailing on volcanic islands on the early Earth,” says Adriana Serrão, lead author of the study.

Study reveals how pH affects the ability of ulcer bacteria to attach

Anna Åberg and Anna Arnqvist Björklund.
Photo Credit: Mattias Pettersson

A study by Anna Arnqvist's research group at Umeå University reveals molecular details about the gastric pathogen Helicobacter pylori's ability to bind to an inflamed stomach and how this is controlled by the stomach's pH. Increased understanding of how H. pylori bacteria can cause a persistent lifelong infection is an important piece of the puzzle in order to ultimately identify the characteristics that contribute to disease.

When the stomach becomes infected with the gastric pathogen Helicobacter pylori, the infection lasts for life if it is left untreated. The infection can cause peptic ulcer disease as well as stomach cancer. The environment within the stomach undergoes continuous changes, requiring the bacteria to adapt by adjusting the expression of certain proteins based on the prevailing conditions.

It is commonly assumed that the stomach has a low pH. However, the pH levels vary significantly, ranging from the highly acidic environment in the stomach lumen to largely neutral conditions at the outermost layer of the stomach epithelial cells, which is protected by a mucus layer. It is in the mucus layer or tightly attached to the outermost cell layer that most H. pylori bacteria are found. The expression of many genes is regulated in response to pH, causing the bacterium to produce varying amounts of proteins depending on the pH of its surroundings.

Tuesday, March 19, 2024

Cells harvested from urine may have diagnostic potential for kidney disease, find scientists

Image Credit: AI generated / Gemini Advance

Genes expressed in human cells harvested from urine are remarkably similar to those of the kidney itself, suggesting they could be an important non-invasive source of information on the kidney.

The news offers hope that doctors may one day be able to investigate suspected kidney pathologies without carrying out invasive procedures such as biopsies, raising the tantalizing prospect of earlier and simpler disease detection.

The impact of late detection of kidney disease can be severe and can lead to serious and sometimes life-threatening complications.

The team led by University of Manchester scientists measured the levels of approximately 20,000 genes in each cellular sediment sample of urine using a technique called transcriptomics.

The British Heart Foundation-funded study benefited from access to the world's largest collection of human kidney samples collected after surgery or kidney biopsy conducted before transplantation, known as the Human Kidney Tissue Resource, at The University of Manchester.

They extracted both DNA and RNA from each sample and connected information from their analysis, together with data from previous large-scale analyses of blood pressure (called genome-wide association studies), using sophisticated computational methods.

Inflammatory bowel disease after a stem cell transplant

Additional genetic testing could make bone marrow donations even safer.
Image Credit: Gerd Altmann

A stem cell donation saves a leukemia sufferer’s life. Five years later, the patient develops a chronic inflammatory bowel disease that occurs very rarely following a transplant. Researchers from the University of Basel and University Hospital Basel have studied the case and are calling for more extensive genetic analyses in bone marrow donors.

In many forms of blood cancer, a transplant of blood stem cells is the only chance of a cure. This procedure involves first eliminating the patient’s degenerated blood stem cells and then building up their immune system again with stem cells from a donor.

So that the new immune system doesn’t turn against the recipient’s body, a series of tissue markers must match the recipient and donor. This criterion is investigated as standard. Now, a research team led by Professors Petr Hrúz from Clarunis (University Digestive Health Care Center Basel) and Mike Recher from the University of Basel and University Hospital Basel has shown that it would also be sensible to carry out a more extensive genetic analysis.

Writing in the Journal of Clinical Immunology, the team describes the case of a man who developed a chronic inflammatory bowel disease (Crohn’s disease) five years after receiving a blood stem cell transplant for leukemia. Genetic analysis revealed that a mutation had been transplanted along with the blood stem cells from the donor. This mutation affected the operation of a factor called TIM-3, a key regulator of the immune system. The donor, on the other hand, was and remains in apparently good health.

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