A hidden molecular defect in inflammatory bowel disease may help explain why flare-ups can return even when patients appear well. Even when inflammatory bowel disease appears under control, intestinal cells may remain primed to die. In a WEHI-led study, researchers found this hidden molecular defect in patients with few or no symptoms, and higher levels [...]
The patient: A 47-year-old woman in Canada
The symptoms: The woman underwent a lung transplant to treat interstitial lung disease, which involves harmful inflammation and scarring of lung tissue. While recovering in the hospital, she ate a bowl of breakfast cereal, which activated a nearly two-hour episode of flushing, itching, shortness of breath and low blood pressure.
This severe, life-threatening allergic reaction is known as anaphylaxis. A report of the woman's case does not mention specific treatment she received for this reaction, but it notes that it resolved after two hours.
(Treatment for anaphylaxis involves epinephrine (also called adrenaline), and it can also require antihistamines, cortisone, oxygen and beta-agonists, such as albuterol, which help improve breathing.)
What happened next: The woman experienced the same symptoms in the weeks after being discharged from the hospital — after eating a coconut cream pie and after having an almond candy bar.
The diagnosis: Two months after her lung transplant, the woman underwent a skin-prick allergy test, which revealed a sensitivity to peanut and pine nut allergens. She did not have an allergic response to tree nuts, such as the almonds in the candy bar, nor to coconut. None of the foods that triggered her symptoms were known to contain peanuts, but none were certified as peanut-free, either.
Notably, the woman's lung donor had been a 12-year-old boy with a known peanut allergy but no history of anaphylaxis. Her doctors theorized that the transplanted lung tissue contained immune cells from the donor that were sensitized to nut allergens.
The treatment: The woman did not receive a specific treatment to get rid of this new allergic response. However, the sensitivity subsided in follow-up skin-prick tests, and they had disappeared completely by a year after her surgery. She ate peanuts in a supervised setting a few months after the one-year mark and had no reaction.
The doctors reasoned that the sensitized immune cells from the donor must have cleared from her body.
What makes the case unique: Only one other case of peanut allergy following a lung transplant had been documented before the woman's case was published in 2011.
Scientists had only recognized the risk of allergies being passed from organ donors to recipients a little over a decade before the report, according to a 2025 review of such instances. Doctors had previously reported allergy transfer linked to bone marrow transplants, which makes sense given that bone marrow produces immune cells. But the first known donor-acquired allergy from a solid-organ transplant was observed in 1997 following a combined kidney-liver transplant from a donor who was allergic to peanuts.
The authors of the 2025 review noted that donor-acquired allergies are more commonly associated with lung and liver transplants than with transplants of other solid organs. That could be because these organs are rich in a type of immune cell that produces allergen-specific antibodies, called B lymphocytes.
Other potential culprits for donor-acquired allergies are mast cells and basophils, two types of immune cell that bind to those allergen-specific antibodies. The cells hold onto the antibodies, and when they encounter an allergen, they release the inflammatory compounds responsible for anaphylaxis.
In the woman's case, a blood test for peanut-specific antibodies came back negative. This suggested that her body was not continually generating the antibodies. That could serve as possible evidence that her reaction was caused by antibodies bound to mast cells or basophils within the donor tissue, rather than antibodies produced by lymphocytes.
That said, the woman's reaction to the skin-prick test could imply that lymphocytes were still involved in the allergic reaction, the doctors added, as they did not know whether mast cells or basophils could migrate to the skin the way circulating antibodies could.
Regardless of the cell type behind the woman's peanut allergy, the sensitivity faded after a year, consistent with other cases described in the 2025 review. Still, the review authors called for better donor allergy labels to inform allergy testing and treatment for organ recipients. The doctors in the case report came to a similar conclusion, noting that detailed donor allergy histories and skin-prick testing after organ transplant could help identify donor-acquired allergies.
For more intriguing medical cases, check out our Diagnostic Dilemma archives.
This article is for informational purposes only and is not meant to offer medical advice.
Bat DNA may hold clues to a long and healthy life, according to an international team of researchers.
These small creatures grace the night skies with extremely long lifespans and low cancer rates—traits that may ultimately benefit humanity if scientists can figure out how bats achieve them. Now, in a recent paper published in Nature, scientists from the University of Vermont and Penn State University led an international team investigating bats’ immune systems.
The paper’s crucial discovery was that bat DNA reveals the creatures encode genomic changes to handle exposure to environmental pathogens.
“Pathogen adaptation, longevity, and cancer resistance—they are fundamentally linked,” explained co-lead author Elise Lauterbur, an assistant professor of evolutionary biology at the University of Vermont. “Many of the genes that have adapted to viruses in bats are genes that are also involved in longevity and cancer resistance.”
Bats make an ideal study subject as they are only second to rodents in diversity, allowing scientists to study a wide variety of features in a single order.
“If you look at two bats, the same size, one lives 3 years the other lives 30 years and they are very closely related, like humans and Neanderthals, you can essentially find a very small number of genetic changes that leads to a very big change in their lifespan,” said co-lead author Juan Manuel “Manny” Vazquez, an assistant professor at Penn State University. “And that is kind of the Holy Grail for evolutionary medicine.”
The work focused on Myotis, one of the largest bat genera, whose members are found across much of the globe outside Antarctica. Eight Myotis species came under the microscope, with the team experimenting on cultured cells and analyzing their genomes. Among the species sampled were little brown bats (Myotis lucifugus), known both for their long lifespans, even among bats, and their susceptibility to the deadly white-nose syndrome, a fungal disease.
Even the researchers’ sample-collection methods were novel. They developed a technique akin to ear-piercing to collect small tissue samples from bat wings, which were then used to establish cell cultures. The team says this both spared the animals’ lives and produced more scientifically useful samples.
In their detailed examination, the researchers identified evidence of past events in which Myotis bats encountered pathogens and how adaptations to those viruses were selected for during their evolution.
Their work identified specific genomic changes, including the duplication or deletion of genes, associated with adaptation to environmental pathogens. This illuminated important differences in bats’ responses to DNA and RNA viruses compared with humans and other primates, potentially contributing to bats’ long, healthy lifespans.
Comparatively, human evolution shows stronger selection involving proteins that interact with RNA viruses like influenza, while bats show stronger selection involving proteins that interact with DNA viruses such as herpesviruses. These differences may help explain the distinct ways bats and primates have adapted to viral threats.
The team also identified genetic mechanisms that could help explain bats’ resistance to cancer and other age-related diseases. In some cases, duplicated genes can diversify their functions, allowing different copies to perform distinct roles. According to the researchers, this may provide immune advantages that help bats combat multiple viruses while also contributing to pathways associated with longevity.
Another important finding was that while most mammals contain one copy of the immune-related gene PRKN, some bat species contain two or even three copies, suggesting that additional copies may offer evolutionary advantages. The team says this could provide important insights for future cancer research, given bats’ unusual ability to repair or eliminate damaged cells.
The research doesn’t point to immediate treatments for humans, but it does provide starting points for reconsidering human illness in the context of bat immunology and evolution.
“Everything is connected,” Vazquez concluded. “Everything uses the same shared set of biology. … We don’t have to treat all of these different problems as silos. We can now start focusing on systems like bats to understand how we can solve multiple human age-related diseases.”
The paper, “Insights into Longevity and Virus-Driven Adaptation from Myotis Bat Genomes,” appeared in Nature on August 26, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.
How immune cells develop and retain memory may work differently than medical scientists previously believed, according to an international team of researchers.
The new work shows that T cells—white blood cells essential to immune function—can respond to the physical properties of their surroundings through a kind of cellular sense of touch.
The researchers published the work in Nature Immunology, altering our understanding of how immune cells develop, and potentially improving scientists’ understanding of how the immune system adapts to the varied physical environments found throughout the human body.
The various specialized types of T cells serve crucial roles in the immune system. Some directly fight infections, while others help coordinate the immune response. Scientists have long believed that biochemical signals help shape the memory T cells that persist in tissues following an infection, preserving the body’s ability to respond to previously encountered threats. How these cells migrate and eventually settle into strategic positions throughout the body is a key part of the immune response.
As T cells travel through the body, they continually monitor for signs of pathogens. When a threat is detected, T cells can enter affected tissues and help clear the infection. Once the invaders have been repelled, some T cells remain in the tissue to guard against reinfection. These tissue-resident memory T cells help defend against previously encountered threats but can also play roles in autoimmune disorders and the rejection of transplanted tissue.
Over their lifetimes, T cells can develop into increasingly specialized forms. Naive T cells have not yet encountered the specific antigen they are capable of recognizing. Following activation, they can differentiate into effector T cells that help target a particular threat, with some eventually developing into long-lived memory cells.
Tissues in our bodies vary widely in stiffness, ranging from the very soft adipose tissue that makes up our body fat to the much stiffer skeletal muscle tissue. These differences raise an interesting question: how do T cells remain strong enough to survive the pressures of stiffer tissues while staying soft enough to change shape as they slide through obstacles in our bodies?
For their laboratory experiments, the researchers reproduced typical tissue stiffnesses using specially engineered collagen gels. They then placed human and mouse immune cells into the gels and discovered that T cells were more likely to develop characteristics associated with tissue-resident memory cells in stiffer environments.
Previously, scientists believed biochemical signals were the primary driver of tissue-resident memory T cell development. In their new research, the team found that these cells use touch to sense the mechanical pressure of their surroundings, dictated by tissue stiffness, and adjust their morphology to compensate.
“This is an exciting fundamental finding that challenges the way we think about immune cells,” said lead author Judith Mandl, a professor in McGill University’s Department of Physiology. “It suggests T cells can ‘feel’ their surroundings and adapt to them, making the physical environment an active force in shaping their behaviour.”
While T cells normally function to protect us from illness, they can occasionally create problems of their own. Patients with autoimmune diseases and allergies may see these immune cells begin attacking healthy tissue. Additionally, organ transplant patients typically require immunosuppressant drugs to stop their T cells from rejecting the new organ.
“Tumours are often dense and physically difficult for immune cells to penetrate. Understanding how T cells adapt to these environments could help researchers design cancer immunotherapies that are better able to reach and attack tumours,” said Mandl.
This new research is an important first step in a new understanding of how immune cells differentiate, which could lead to a new foundational understanding of how to correct undesired immune responses.
The paper, “Mechanosensing by T Cells Promotes a Tissue-Resident Memory Transcriptional Program,” appeared in Nature Immunology on July 3, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org.
A shortage of one common nutrient could help cancer cells and viruses hide from the immune system. Researchers at Rockefeller University found that a shortage of arginine, an amino acid obtained from food and produced by the body, can interrupt the cellular machinery needed to make MHC-I proteins. These proteins act as a surveillance system, [...]A protein called TRAILshort may act as a central immune brake that limits T-cell responses and CAR-T therapy. Cancer cells can weaken the immune system by producing a protein that prevents its most important defenders from attacking. Mayo Clinic researchers have identified how this protein works, revealing a possible target for treatments designed to improve [...]T cells may use a previously unknown CD64-dependent pathway to attack acute myeloid leukemia. T cells are generally thought to identify cancer through a well-established molecular recognition system. Yet when researchers removed a key part of that system from acute myeloid leukemia (AML) cells, the immune cells continued killing them. The unexpected result led scientists [...]Over the past couple of weeks, my immune system has been struggling to fight off a cold. It’s been unpleasant, as all colds are. But throughout this time—in defiance of my plight—I’ve been waging my own war against immune systems, thanks to Pathogenic, a new roguelite twin-stick shooter from developer Aberrant Labs.
As I've downed endless shots of ineffective cough syrup, I’ve done little else with my free time than repeatedly take on the role of a bodily invader. And let me tell you: Being on the enemy’s side is much more fun. Really fun, as it turns out.
Action roguelites are a dime a dozen these days, and it takes something special to stand out. So as quiet Internet whispers turned into widespread cacophonous praise—the little indie game quickly racked up 100,000 sales and an “overwhelmingly positive” review score on Steam—I set aside my default skepticism and gave it a shot.
© Aberrant Labs/Slug Disco
A natural supplement strengthened lasting anticancer immune responses in obese mice. Weight loss can improve many aspects of health, but the immune system may not recover as quickly. Obesity can leave behind long-lasting changes in the bone marrow, where immune cells are formed, potentially weakening the body’s ability to respond to cancer even after excess [...]Researchers have found that the natural compound spermidine can help improve vaccine responses in older adults by reducing molecular markers of immune system aging. A vaccine shot can look the same from one arm to the next, but the immune system beneath the skin may not respond with the same force. In older adults, that [...]New research suggests aging ovaries may help shape inflammation across the body.The causes of inflammatory bowel disease (IBD) are poorly understood, but now, scientists have pinpointed a runaway immune response that may underlie the condition in some patients.
IBD, which is characterized by chronic inflammation in all or part of the digestive tract, affects millions of people worldwide. Its principal forms are Crohn's disease, which can occur at any point of the gastrointestinal tract, and ulcerative colitis, which affects only the colon and rectum.
While IBD patients may experience similar inflammation, the underlying cause may be different. Understanding those differences could potentially unlock new, targeted angles for treatment, researchers concluded in the new study.
"Identifying these patients early could eventually allow clinicians to move more quickly toward therapies that address the specific mechanism of disease rather than relying on a trial-and-error sequence of medications," Dr. Brad Pasternak, medical director of the IBD Clinic at Phoenix Children's Hospital, who was not involved in the work, told Live Science in an email.
The genetics of IBD are complex, with past studies linking the condition to 300 "hotspots" throughout the genome. The strongest known genetic risk factor for ulcerative colitis is a gene variant called HLA-DRB1*01:03, but how this variant contributes to IBD has been unclear.
The new study, published June 10 in The New England Journal of Medicine, helps connect the dots.
A major clue had emerged in previous research by the same team, which tested the blood of two children with IBD. The kids had autoantibodies — immune proteins that target the body itself rather than germs — that were neutralizing a key anti-inflammatory protein called interleukin-10 (IL-10).
IL-10 normally works by inhibiting the secretion of pro-inflammatory proteins, so patients whose bodies block IL-10 are effectively releasing a brake that should be holding off inflammation, Pasternak said.
The researchers suspected that these autoantibodies could be one factor causing IBD. In their latest study, they sought to find out whether more IBD patients had the same autoantibodies.
The study included data from over 4,900 people with IBD and over 1,000 without the condition. Using two separate lab tests, the researchers analyzed blood samples from both groups, finding the autoantibody in 173 of the IBD patients, or about 3.5%. The autoantibody was virtually absent from the blood of the comparison group.
Then, in lab experiments, the team exposed immune cells to blood from the IBD patients who carried the autoantibody. This lowered the amount of IL-10 while triggering a pro-inflammatory response.
Study co-author Dr. Holm Uhlig, a pediatric gastroenterologist at the University of Oxford, told Live Science that identifying what drives the formation of the autoantibodies will be "a question of intense interest." For now, though, their data suggests that patients carrying HLA-DRB1*01:03 are far more likely to have autoantibodies blocking IL-10 than those without the variant.
Historically, the variant has been associated with severe IBD that can require major surgery to treat. "Currently, autoimmune responses are not at all part of the therapeutic repertoire, and that's why we feel it's a relevant study," Uhlig said.
Uhlig also noted that the subgroup of 3.5% of patients they identified is a "significant number," given the large overall number of IBD patients worldwide.
In general, many IBD patients are currently treated with therapies that broadly suppress inflammatory pathways, Pasternak said, but not everyone responds to treatment. This study points to a potential way to someday tailor treatments to the mechanism driving specific patients' diseases, he said.
Aside from offering personalized treatments for IBD patients, Uhlig said their findings may improve diagnoses.
"Patients could undergo genetic testing already in the early stage of their disease diagnosis," he said, "and then it would determine their susceptibility to develop autoantibodies."
This article is for informational purposes only and is not meant to offer medical advice.
A new study overturns long-held assumptions about the cause of the rare inflammatory disorder MKD, identifying a previously overlooked immune defect. Why does a routine infection trigger dangerous inflammation in some people? Researchers studying mevalonate kinase deficiency (MKD), a rare inherited autoinflammatory disorder, may have finally found the answer. Scientists at the Garvan Institute of [...]In an era marked by remarkable advances in antiretroviral therapy (ART), the survival and quality of life of individuals living with HIV have dramatically improved. Yet, new research is now illuminating the complex interplay between immune system dysregulation and the emergence of cardiovascular disease (CVD) in a particularly vulnerable population: adolescents infected with HIV perinatally. A groundbreaking study, published in Nature Communications, spearheaded by Alles, Gunasena, Kettelhut, and colleagues, sheds light on the critical role of natural killer (NK) cell dysfunction in potentiating cardiovascular complications among these young patients, even while on effective ART.
Perinatally acquired HIV represents a unique clinical challenge, as infection occurs during a critical window of immune system development. While ART suppresses viral replication effectively, it does not fully restore immune homeostasis. This dysregulation manifests not only in the persistence of immune activation but also in aberrant immune cell profiles, including those of natural killer cells—a subset of lymphocytes crucial in antiviral defense and immune surveillance. The new findings suggest that disturbances in NK cell function are more than mere epiphenomena; they could actively contribute to the pathogenesis of cardiovascular abnormalities in this patient group.
The study emphasizes that NK cells in adolescents with perinatal HIV exhibit marked phenotypic and functional changes compared to age-matched uninfected controls. These alterations include impaired cytotoxic activity and aberrant expression of activating and inhibitory receptors. Such changes compromise the ability of NK cells to regulate inflammation and eliminate infected or damaged cells, fostering an environment conducive to vascular injury and endothelial dysfunction. This mechanistic insight is critical, as endothelial health is a cornerstone of cardiovascular stability.
By integrating immunophenotyping, functional assays, and clinical cardiovascular assessments, the researchers drew a comprehensive picture linking NK cell abnormalities with early signs of CVD. The adolescents studied demonstrated increased arterial stiffness, altered lipid profiles, and biomarkers indicative of systemic inflammation—all hallmarks of an accelerated atherosclerotic process. Intriguingly, these cardiovascular perturbations persisted despite sustained viral suppression, highlighting that viral load alone cannot explain the heightened cardiovascular risk.
The pathophysiology proposed by the authors centers on a chronic, low-grade inflammatory milieu driven, in part, by dysfunctional NK cell signaling. Typically, NK cells modulate inflammation through cytokine secretion and direct cytolysis of aberrant cells, maintaining tissue homeostasis. However, dysregulated NK cells may either fail to contain inflammatory stimuli or contribute to pathological immune activation. This shift not only exacerbates endothelial dysfunction but may induce vascular remodeling and fibrosis, setting the stage for premature cardiovascular disease.
Molecular analyses revealed upregulation of several pro-inflammatory pathways within NK cells isolated from affected adolescents. Notably, transcriptional profiles highlighted increased expression of genes involved in inflammasome activation, oxidative stress responses, and cell senescence markers—factors strongly implicated in vascular pathology. These insights open avenues for targeted therapeutic interventions aimed at restoring NK cell function and interrupting the inflammatory cascade implicated in CVD progression.
Importantly, the study’s implications go beyond HIV care alone. The concept that immune cell dysfunction can independently drive cardiovascular disease adds a crucial dimension to our understanding of immune-mediated comorbidities. It underscores the necessity of holistic medical care approaches that address the immunological underpinnings of chronic disease states, especially in populations with lifelong exposure to immunological stressors like perinatal HIV.
The findings also raise compelling questions about the adequacy of current ART regimens in mitigating long-term non-AIDS complications. While ART excels at viral suppression, it may not sufficiently address immune reconstitution or the correction of immune cell dysregulation. Future therapeutic strategies might need to incorporate immunomodulatory agents that specifically target NK cell pathways or inflammatory mediators to reduce cardiovascular risk.
Moreover, this study highlights the pressing need for comprehensive cardiovascular screening in adolescents with perinatally acquired HIV. Traditional risk assessment paradigms may not capture the unique pathophysiological mechanisms at play in this population. Early detection of subclinical vascular changes could catalyze timely preventative interventions, potentially improving long-term outcomes.
From a broader perspective, the research invites a re-examination of how chronic infections shape the immune landscape over an individual’s lifespan and influence multisystem disease trajectories. It suggests a paradigm where the immune system’s ongoing attempts to control persistent infection or immunologic insults inadvertently promote collateral tissue damage, exemplified here by cardiovascular impairment.
Technological advances in multi-omics and single-cell profiling have been pivotal in unraveling the nuanced dysfunctions within NK cell subsets elucidated by this work. These tools enable high-resolution mapping of immune cell states and their interactions with the vascular microenvironment, fostering a deeper mechanistic understanding that might have remained elusive with conventional methods.
The involvement of NK cells in this context may also intersect with other immune-mediated pathways, including those involving T cells and monocytes/macrophages, which together orchestrate the inflammatory response underpinning atherosclerosis. Understanding these intricate cellular crosstalk networks will be crucial to designing effective immunotherapies.
In light of this evidence, interdisciplinary collaboration between immunologists, cardiologists, and infectious disease specialists becomes more imperative. Integrating expertise from these domains can accelerate the translation of these findings into clinical interventions that mitigate cardiovascular risk among HIV-infected youth, and perhaps beyond.
Finally, this research presents an urgent call to the global health community to prioritize long-term monitoring and holistic management strategies for adolescents living with perinatal HIV. As their life expectancy approaches normality, addressing comorbid conditions such as cardiovascular disease will be essential to ensuring not just survival but sustained health and quality of life.
In summary, the pioneering study by Alles and colleagues illuminates a previously underappreciated contributor to cardiovascular disease risk in adolescents with perinatally acquired HIV on antiretroviral therapy. The demonstration that NK cell dysregulation may be a key mechanistic driver of early vascular pathology underscores the necessity for innovative therapeutic approaches targeting immune dysfunction beyond viral suppression alone. This work marks a significant advance in understanding the complex interdependencies between chronic viral infection, immune regulation, and cardiovascular health, and sets the stage for transformative changes in clinical practice and research paradigms.
Subject of Research:
Natural Killer (NK) cell dysfunction and its role in cardiovascular disease development in adolescents with perinatally acquired HIV undergoing antiretroviral therapy.
Article Title:
NK cell dysregulation may potentiate cardiovascular disease in adolescents with perinatally acquired HIV on antiretroviral therapy.
Article References:
Alles, M., Gunasena, M., Kettelhut, A. et al. NK cell dysregulation may potentiate cardiovascular disease in adolescents with perinatally acquired HIV on antiretroviral therapy. Nat Commun (2026). https://doi.org/10.1038/s41467-026-74602-y
Image Credits: AI Generated
Scientists identified an autoimmune mechanism linked to a major IBD risk gene, opening the door to targeted diagnosis and personalized therapies for thousands of patients. For decades, inflammatory bowel disease (IBD) has been treated as a single disorder, even though patients often experience dramatically different symptoms, disease courses, and responses to therapy. A new study [...]A rare inflammatory condition linked to tattoos is appearing more often in Australia.Scientists have identified supermagnetic macrophages in the livers of homing pigeons (Columba livia domestica) that appear essential for navigation when the Sun is not visible, pointing to an entirely new mechanism for animal magnetoreception.
The post Pigeons May Sense Earth’s Magnetic Field Using Superparamagnetic Immune Cells in Their Livers appeared first on Sci.News: Breaking Science News.
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