In the News

Research advances from the National Institutes of Health (NIH) Intramural Research Program (IRP) often make headlines. Read the news releases that describe our most recent findings:

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Inside the government study trying to understand the health effects of ultraprocessed foods

Associated Press
March 14, 2025

BETHESDA, Md. (AP) — Sam Srisatta, a 20-year-old Florida college student, spent a month living inside a government hospital here last fall, playing video games and allowing scientists to document every morsel of food that went into his mouth.

From big bowls of salad to platters of meatballs and spaghetti sauce, Srisatta noshed his way through a nutrition study aimed at understanding the health effects of ultraprocessed foods, the controversial fare that now accounts for more than 70% of the U.S. food supply. He allowed The Associated Press to tag along for a day.

“Today my lunch was chicken nuggets, some chips, some ketchup,” said Srisatta, one of three dozen participants paid $5,000 each to devote 28 days of their lives to science. “It was pretty fulfilling.”

Examining exactly what made those nuggets so satisfying is the goal of the widely anticipated research led by National Institutes of Health nutrition researcher Kevin Hall.

“What we hope to do is figure out what those mechanisms are so that we can better understand that process,” Hall said.

IRP researchers discover new autoinflammatory disease and uncover its biological cause

Mutations in the RIPK1 gene responsible for CRIA syndrome

Over the last 20 years, three families have been unsuspectingly linked by an unknown illness. Researchers at the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health, and other organizations have now identified the cause of the illness, a new disease called CRIA syndrome. The results were published in the journal Nature.

NHGRI scientific director Daniel Kastner, M.D., Ph.D., a pioneer in the field of autoinflammatory diseases, and his team discovered CRIA, which has symptoms including fevers, swollen lymph nodes, severe abdominal pain, gastrointestinal problems, headaches and, in some cases, abnormally enlarged spleen and liver.

The disorder has characteristics typical of an autoinflammatory disease, where the immune system appears to be activated without any apparent trigger. Although the condition is not life-threatening, patients have persistent fever and swollen lymph nodes from childhood to old age, as well as other symptoms that can lead to lifelong pain and disability.

NIH-developed Zika vaccine improves fetal outcomes in animal model

An experimental Zika vaccine lowered levels of virus in pregnant monkeys and improved fetal outcomes in a rhesus macaque model of congenital Zika virus infection, according to a new study in Science Translational Medicine. The research was conducted by scientists at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and their collaborators from the University of California, Davis; Duke University, Durham, North Carolina; and the University of California, Los Angeles. NIAID scientists developed the experimental vaccine and currently are evaluating it in a Phase 2 human clinical trial. The vaccine uses a small circular piece of DNA, or plasmid, containing genes that encode Zika virus surface proteins to induce an immune response.

Zika virus is primarily transmitted to humans by Aedes mosquitoes; it also can be transmitted through sex. The virus can cause serious birth defects in babies born to mothers who become infected during pregnancy. Ideally, the authors note, a Zika vaccine would be given to adolescents and adults of childbearing age before pregnancy to prevent congenital Zika syndrome.

Large outbreaks of Zika virus in the Americas in 2015 and 2016 led to thousands of cases of congenital Zika syndrome, prompting NIAID scientists to quickly develop and begin clinical trials of the NIAID DNA Zika vaccine. While clinical trials can yield data on safety and how the vaccine performs in recipients, due to the diminished incidence of Zika, conducting a clinical trial that would determine the vaccine’s ability to prevent adverse fetal outcomes has been logistically difficult. Therefore, researchers developed a macaque model of congenital Zika syndrome to provide another way to evaluate the experimental vaccine.

A vial of the NIAID Zika virus investigational DNA vaccine

A vial of the NIAID Zika virus investigational DNA vaccine, taken at the NIAID Vaccine Research Center’s Pilot Plant in Frederick, Maryland.

Pregnancy hypertension risk increased by traffic-related air pollution

Findings give new insights into the connection between poor air quality, children’s health, and mother’s health

A new report from the National Toxicology Program (NTP) suggests that traffic-related air pollution increases a pregnant woman’s risk for dangerous increases in blood pressure, known as hypertension.

NTP scientists evaluated published research on the link between traffic-related air pollution, or TRAP, and hypertensive disorders broken down by pollutant measurements of TRAP, such as particulate matter (PM2.5). PM is the term for a mixture of solid particles and liquid droplets found in the air, and PM2.5 refers to fine inhalable particles, with diameters that are generally 2.5 micrometers or smaller. The average human hair is about 70 micrometers in diameter, about 30 times larger than the largest fine particle.

“What we found when we reviewed the literature is that exposure to PM2.5 from traffic emissions was associated with development of hypertensive disorders in pregnant women,” said Brandy Beverly, Ph.D., lead scientist and researcher at the National Institute of Environmental Health Sciences, part of the National Institutes of Health. “When these women are exposed to PM2.5 during their entire pregnancy, the likelihood of developing preeclampsia increases by about 50%.”

NIH launches first U.S. clinical trial of patient-derived stem cell therapy to replace dying cells in retina

NEI-led study to test safety of treatment for a form of age-related macular degeneration that currently lacks treatment

Researchers at the National Eye Institute (NEI) are launching a clinical trial to test the safety of a novel patient-specific stem cell-based therapy to treat geographic atrophy, the advanced “dry” form of age-related macular degeneration (AMD), a leading cause of vision loss among people age 65 and older. The geographic atrophy form of AMD currently has no treatment.

“The protocol, which prevented blindness in animal models, is the first clinical trial in the U.S. to use replacement tissues from patient-derived induced pluripotent stem cells (iPSC),” said Kapil Bharti, Ph.D., a senior investigator and head of the NEI Ocular and Stem Cell Translational Research Section. The NEI is part of the National Institutes of Health.

The therapy involves taking a patient’s blood cells and, in a lab, converting them into iPS cells, which have the potential to form any type of cell in the body. The iPS cells are programmed to become retinal pigment epithelial (RPE) cells, the type of cell that dies early in the geographic atrophy stage of macular degeneration. RPE cells nurture photoreceptors, the light-sensing cells in the retina. In geographic atrophy, once RPE cells die, photoreceptors eventually also die, resulting in blindness. The therapy is an attempt to shore up the health of remaining photoreceptors by replacing dying RPE with iPSC-derived RPE.

diagram showing how blood cells are turned into retinal pigment epithelial (RPE)l cells

The researchers will take a patient’s own blood cells, and in a lab, convert them into iPS cells capable of becoming any type of cell in the body. The iPS cells are then programmed to become retinal pigment epithelial cells, the type of cell that dies early in the geographic atrophy form of AMD.

Vesicles released by bacteria may reduce the spread of HIV in human tissue

NIH study may inform ways to reduce male-to-female HIV transmission

Nano-sized vesicles released by certain bacteria that inhabit the vagina may protect against HIV infection, suggests a study of human cells and tissues by researchers at the National Institutes of Health and the University of Bologna, Italy. Known as extracellular vesicles, these bubble-like particles are produced by many kinds of cells and are thought to transport molecules from one cell to another. The study was led Leonid Margolis, Ph.D., of NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). It appears in Nature Communications.

The researchers conducted a series of experiments showing that vesicles isolated from four strains of Lactobacillus bacteria interfere with the ability of HIV to infect cells. In one experiment, researchers added vesicles to cultures of immune cells known as T lymphocytes and infected the cultures with HIV. HIV infection in the treated cells was much lower than in the untreated cells. When the researchers increased the quantity of vesicles, a much smaller proportion of cells were infected.

Similarly, treatment with vesicles reduced HIV infection in human lymph and uterine cervix and vaginal tissues. The researchers found that bacterial vesicles suppressed the binding of viruses to the cell surface, an essential step before the virus can infect a cell. Further experiments showed that bacterial vesicles directly affect HIV rather than cells. Exposing the viruses to vesicles reduced the appearance of surface molecules on the virus’ outer covering, which it needs to attach to cells.

Diagram of a bacterial vesicle

Diagram of a bacterial vesicle. Courtesy of the NICHD Section on Intercellular Interactions

Permanent hair dye and straighteners may increase breast cancer risk

Scientists at the National Institutes of Health found that women who use permanent hair dye and chemical hair straighteners have a higher risk of developing breast cancer than women who don’t use these products. The study published online Dec. 4 in the International Journal of Cancer and suggests that breast cancer risk increased with more frequent use of these chemical hair products.

Using data from 46,709 women in the Sister Study, researchers at the National Institute of Environmental Health Sciences (NIEHS), part of NIH, found that women who regularly used permanent hair dye in the year prior to enrolling in the study were 9% more likely than women who didn’t use hair dye to develop breast cancer. Among African American women, using permanent dyes every five to eight weeks or more was associated with a 60% increased risk of breast cancer as compared with an 8% increased risk for white women. The research team found little to no increase in breast cancer risk for semi-permanent or temporary dye use.

"Researchers have been studying the possible link between hair dye and cancer for a long time, but results have been inconsistent," said corresponding author Alexandra White, Ph.D., head of the NIEHS Environment and Cancer Epidemiology Group. "In our study, we see a higher breast cancer risk associated with hair dye use, and the effect is stronger in African American women, particularly those who are frequent users. "

woman rubbing hair dye into her hair

The study found that women who use permanent hair dye and chemical hair straighteners have a higher risk of developing breast cancer than women who don’t use these products.

Cerebral organoid model provides clues about how to prevent virus-induced brain cell death

Scientists have determined that La Crosse virus, which can cause inflammation of the brain in children, affects brain cells differently depending on their developmental stage

Scientists have determined that La Crosse virus (LACV), which can cause inflammation of the brain in children, affects brain cells differently depending on their developmental stage. Neurons — the primary brain cells of the central nervous system — evolve from neural stem cells and during development “commit” to becoming neurons. A new National Institutes of Health study shows that uncommitted neural stems cells generally survive LACV infection, while LACV often kills neurons. The study also shows that neurons infected by LACV can be rescued by interferon, a powerful antiviral protein. The study results appear in the Journal of Neuroinflammation.

LACV is spread by mosquitoes and was first identified in the early 1960s. Most infections in people are mild but the virus sometimes—particularly in children—enters the brain, infects neurons and causes disease ranging from learning and memory difficulties to paralysis, seizures and death. The Centers for Disease Control and Prevention receives reports of an average of 68 LACV encephalitis cases each year in the United States, nearly all east of the Mississippi River.

The NIH scientists, from the National Institute of Allergy and Infectious Diseases Rocky Mountain Laboratories in Hamilton, Montana, used cerebral organoids to model how LACV infects the human brain. Cerebral organoids are small spheres of human brain cells ranging in size from that of a poppy seed to a small pea. Importantly, cerebral organoids contain different neuronal cell types, which allowed the investigators to assess the sensitivity of neural stem cells and neurons to LACV infection.

LACV-infected cerebral organoids

These images taken from LACV-infected cerebral organoids show infected cells (green) and cells that are dying from infection (magenta). The left image also shows neural stem cells (white) that have the potential to become neurons; these cells are rarely dying. In contrast, the image on the right shows committed neurons (white), many of which are shown to be dying.

Four IRP researchers elected as Fellows of the American Association for the Advancement of Science

The American Association for the Advancement of Science (AAAS) has elected four IRP investigators as AAAS Fellows this year. These incredibly accomplished individuals are among 443 scientists chosen as 2019 AAAS Fellows in recognition of their extraordinary achievements in advancing science:

John A. Beutler, Ph.D., of the National Cancer Institute (NCI) identifies and studies natural products that have the potential to be used as cancer treatments. He also builds and maintains a library of chemicals used to support high-throughput screening of compounds for molecularly-targeted cancer drug discovery.

Francesco DeMayo, Ph.D., of the National Institute of Environmental Health Sciences (NIEHS) studies the molecular mechanisms that regulate the functioning of the female reproductive system and the lungs, as well as how environmental factors contribute to diseases like endometriosis, endometrial cancer, and lung cancer.

R. Douglas Fields, Ph.D., of the National Institute of Child Health and Human Development (NICHD) studies the molecular and cellular mechanisms by which functional activity in the brain regulates the development of the nervous system during the periods shortly before and shortly after birth.

Kelly G. Ten Hagen, Ph.D., of the National Institute of Dental and Craniofacial Research (NIDCR) studies the process by which sugar molecules are attached to cellular proteins — known as glycosylation — in order to determine how it influences development and disease.

Visit our Honors page to find out more about other honors and distinctions bestowed upon IRP investigators.

the four IRP investigators elected as 2018 AAAS Fellows

The IRP's 2019 AAAS Fellows. Clockwise from top-left: R. Douglas Fields, Francesco DeMayo, John A. Beutler, and Kelly G. Ten Hagen.

High amounts of screen time begin as early as infancy, IRP study suggests

Children of first-time mothers, those in home-based childcare log most screen time

Children’s average daily time spent watching television or using a computer or mobile device increased from 53 minutes at age 12 months to more than 150 minutes at 3 years, according to an analysis by researchers at the National Institutes of Health, the University at Albany and the New York University Langone Medical Center. By age 8, children were more likely to log the highest amount of screen time if they had been in home-based childcare or were born to first-time mothers. The study appears in JAMA Pediatrics.

“Our results indicate that screen habits begin early,” said Edwina Yeung, Ph.D., the study’s senior author and an investigator in the Epidemiology Branch of NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). “This finding suggests that interventions to reduce screen time could have a better chance of success if introduced early.”

NICHD researchers and their colleagues analyzed data from the Upstate KIDS Study, originally undertaken to follow the development of children conceived after infertility treatments and born in New York State from 2008 to 2010. Mothers of nearly 4,000 children who took part in the study responded to questions on their kids’ media habits when they were 12, 18, 24, 30, and 36 months of age. They also responded to similar questions when the children were 7 and 8 years old. The study compiled additional demographic information on the mothers and children from birth records and other surveys.

Living in ethnic enclaves may improve pregnancy outcomes for Asian/Pacific Islanders, IRP study suggests

Among Asian/Pacific Islander women living in the United States, those who reside in ethnic enclaves — areas with a high concentration of residents of a similar ancestry — are less likely to have pregnancy or birth complications than those living in other areas, suggests a study by researchers at the National Institutes of Health and other institutions. The findings appear in the Journal of Racial and Ethnic Health Disparities.

Women in enclaves were less likely to have gestational diabetes, to deliver preterm, or to have an infant who was small for gestational age (a possible indicator of failure to grow adequately in the uterus). The researchers theorize that living in ethnic enclaves may improve health by offering easier access to health professionals of similar ancestry, access to traditional diets that are healthier than typical U.S. diets, and less incentive to engage in unhealthy habits like smoking and alcohol abuse.

“Our findings suggest that providing Asian/Pacific Islanders with culturally appropriate health care resources may be a key factor in overcoming disparities,” said the study’s senior author, Pauline Mendola, Ph.D., of the Epidemiology Branch at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD).

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This page was last updated on Friday, March 21, 2025