Breaking News
April 18, 2019 - Study uncovers new biomarker for personalized cancer treatments
April 18, 2019 - Scientists enter research collaboration to find a cure for cancer
April 18, 2019 - Study to compare benefits of tai chi and mindfulness meditation on MS symptoms
April 18, 2019 - Gestational diabetes during pregnancy may increase risk of type 1 diabetes in children
April 18, 2019 - Is a New Remedy for Body Odor on the Horizon?
April 18, 2019 - Orthostatic hypotension – Genetics Home Reference
April 18, 2019 - Healing the heartbreak of stillbirth and newborn death
April 18, 2019 - Conference to highlight advances in human immune monitoring, bioinformatics | News Center
April 18, 2019 - Bacteria use viruses for self-recognition, study reveals
April 18, 2019 - New adhesive patch could help reduce post-heart attack muscle damage
April 18, 2019 - Researchers analyze the effects of dark play in a serious video game
April 18, 2019 - Filial cannibalism and offspring abandonment may be forms of parental care
April 18, 2019 - Two proteins act in concert to maintain a healthy heart in mice, shows study
April 18, 2019 - Scientists create a functioning 3D printed heart
April 18, 2019 - Non-invasive vagus nerve stimulation improves disease symptoms in patients with rheumatoid arthritis
April 18, 2019 - Majority of men struggle to understand diagnosis and treatment of prostate cancer
April 18, 2019 - Researchers create new small molecules that may combat equine encephalitis viruses
April 18, 2019 - Animal-assisted therapy improves social behavior in patients with brain injuries
April 18, 2019 - Some viruses help protect harmful bacteria in CF patients | News Center
April 18, 2019 - Outpatient healthcare providers inappropriately prescribe antibiotics to 40% of patients
April 18, 2019 - Men who have a resting heart rate of 75 bpm are twice as likely to die early
April 18, 2019 - Novel serum biomarkers to detect NAFLD-related fibrosis
April 18, 2019 - New study delves deeper into individual genomic differences than ever before
April 18, 2019 - Gilead and Galapagos Announce Filgotinib Meets Primary Endpoint in the Phase 3 FINCH 3 Study in Methotrexate-Naïve Rheumatoid Arthritis Patients
April 18, 2019 - Emotional mirror neurons found in rats
April 18, 2019 - Sylvia Plevritis appointed chair of biomedical data science | News Center
April 18, 2019 - Yeast strain provides manufacturing boost to low-calorie sweetener derived from lactose
April 18, 2019 - C-Path and CDISC release global Therapeutic Area Standard for HIV research
April 18, 2019 - Integrating AI to analyze imaging data allows early recognition of heart disease
April 18, 2019 - Low-cost, high-speed algorithm may allow animal-free chemical toxicity testing
April 18, 2019 - HPV-negative cervical cancers are more aggressive with worse prognosis
April 18, 2019 - AI detects prostate cancer with same level of accuracy as experienced radiologists
April 18, 2019 - Study resolves sex differences in psychiatric illness risk
April 18, 2019 - Novartis Announces FDA Filing Acceptance and Priority Review of Brolucizumab (RTH258) for Patients with Wet AMD
April 18, 2019 - Cocktail of common antibiotics can fight resistant E. coli
April 18, 2019 - Persis Drell to give keynote address at medical school diploma ceremony | News Center
April 18, 2019 - EpicTogether: Remembering Our Why
April 18, 2019 - Study identifies novel loci contributing to asthma susceptibility in adults
April 18, 2019 - Gut bacteria and pregnancy
April 18, 2019 - New study finds that screening could help prevent rare types of cervical cancer
April 17, 2019 - Spatial orgnization of the genome can be altered using small molecules
April 17, 2019 - AEDs Tied to Higher Pneumonia Risk in Alzheimer Patients
April 17, 2019 - Telemedicine tied to more antibiotics for kids, study finds
April 17, 2019 - Two medical students awarded 2019 Soros Fellowships for New Americans | News Center
April 17, 2019 - Sociologist Constance A. Nathanson Awarded Guggenheim Fellowship
April 17, 2019 - Empathy and hormones could account for aggressive behavior in children, shows study
April 17, 2019 - Researchers develop oral appliance to help sufferers of sleep apnea
April 17, 2019 - Neuronal transport factor detects its target transcripts in more complex manner than previously thought
April 17, 2019 - New drug-delivery system senses high oxidant levels, responds to body chemistry and environment
April 17, 2019 - Health Tip: Horseback Trail Riding Safety
April 17, 2019 - Scientists outline the promises and pitfalls of machine learning in medicine
April 17, 2019 - $12 million grant renewal for flu vaccine research | News Center
April 17, 2019 - Lisa Kachnic, MD, Joins Columbia University as Chair of Radiation Oncology
April 17, 2019 - New study sheds light on how extreme temperature hampers spermatogenesis in insects
April 17, 2019 - Study tests high-tech, non-pharmaceutical way to address ADHD and distractibility
April 17, 2019 - New EZ-2 evaporator for clinical biochemistry sample preparation
April 17, 2019 - Fat shaming celebrities may make women more judgemental about being overweight
April 17, 2019 - Magic mouthwash effectively reduces mouth sore pain caused by radiation therapy
April 17, 2019 - CBD could help slip medications into the brain
April 17, 2019 - Scientists characterize 2017 pneumonic plague outbreak in Madagascar
April 17, 2019 - Human iPSC-derived MSCs from aged individuals acquire a rejuvenation signature
April 17, 2019 - Gun Research Is Suddenly Hot
April 17, 2019 - Employee wellness programs provide little health benefits
April 17, 2019 - Cannabis users could be more tolerant to anesthesia agents
April 17, 2019 - Study suggests new approach to treat renal fibrosis
April 17, 2019 - Green roofs may improve indoor air quality, study shows
April 17, 2019 - Selumetinib Granted U.S. Breakthrough Therapy Designation in Neurofibromatosis Type 1
April 17, 2019 - Fasting-mimicking diet holds promise for treating people with inflammatory bowel disease
April 17, 2019 - Daily cannabis use significantly higher among individuals with serious psychological distress
April 17, 2019 - Victims of bullying have greater chances of mental health problems, unemployment in later life
April 17, 2019 - Strategies to achieve greater vaccination coverage throughout Europe
April 17, 2019 - Online atlas created to identify, classify protein signatures present at AML diagnosis
April 17, 2019 - £1.8 million award to boost Crohn’s disease research
April 17, 2019 - Oxytocin blocks excess drinking in alcohol-dependent rats
April 17, 2019 - Rutgers researchers identify new factor essential for maintaining stem cells in the brain and gut
April 17, 2019 - Universal late pregnancy ultrasound improves health of mothers, babies and could be cost saving
April 17, 2019 - Cosmo Pharmaceuticals Announces Submission of Remimazolam NDA to FDA
April 17, 2019 - Stopping inflammation from becoming chronic
April 17, 2019 - Planned Parenthood’s ‘Risky Strategy’ To Update Its Image
April 17, 2019 - Common sleep myths may pose a significant public health threat
High-fat, high-cholesterol diet depletes ranks of artery-protecting immune cells

High-fat, high-cholesterol diet depletes ranks of artery-protecting immune cells

image_pdfDownload PDFimage_print

New research from scientists at the La Jolla Institute for Allergy and Immunology shows how a diet high in fat and cholesterol depletes the ranks of artery-protecting immune cells, turning them into promoters of inflammation, which exacerbate atherosclerotic plaque buildup that occurs in cardiovascular disease. The team has also found that high density lipoproteins (HDL)- more commonly known as “good cholesterol”- counteract this process, helping the protective immune cells maintain their identity and keep arteries clear.

The study published March 15, 2018, in the journal Nature Communications was led by LJI scientists Dalia Gaddis, Ph.D., and Catherine Hedrick, Ph.D.

Inflammation is a key contributor to the hardening and narrowing of the arteries known as atherosclerosis- a condition that can lead to heart attack or stroke. Hedrick’s lab is investigating the roles that immune cells play in this process and how the function of different immune cells can change as atherosclerosis progresses.

“People think atherosclerosis is just about cholesterol, diet, and exercise, but it’s actually an immune disease,” says Dalia Gaddis, Ph.D., a postdoctoral researcher in Hedrick’s lab. “The blockage of arteries is very much due to the immune system reacting to excess cholesterol and lipids in the walls of blood vessels.”

Different subsets of immune cells have opposing roles in atherosclerosis- some contribute to the build-up of plaques, and others protect against it, Gaddis explains. In the current study, she and her colleagues focused on protective cells called regulatory T cells, or Tregs. Tregs prevent the development of atherosclerosis. But researchers have found that when mice are fed a high-fat, high-cholesterol diet- also known as a Western diet- their numbers of protective Tregs decline.

Gaddis wanted to track regulatory T cells in the mice during this process to find out what was happening to them. Typically, scientists look for a protein called Foxp3 to identify regulatory T cells, but this marker is lost when the cells are reprogrammed into another cell type. So Gaddis used mice in which regulatory T cells would be tagged with two fluorescent markers. One, a yellow marker on the Foxp3 protein, allowed her to easily recognize all regulatory T cells. The second tag- a red one- would also be produced by regulatory T cells and then retained regardless of their fate, enabling the researcher team to track the cells in the blood vessels and atherosclerotic plaques even if they changed their identity and stopped making Foxp3.

To begin her experiments, Gaddis fed some of the mice a western diet. After 15 weeks of this regime, she examined the animals’ immune cells. The differences were clear. Gaddis found regulatory T cells in the aorta- the large artery that carries blood from the heart to the rest of the body- in all of the mice. But in the animals that had consumed the Western diet, she also saw significant numbers of “ex Tregs” in the lymph nodes and aorta.

Molecular analyses revealed that some of the former regulatory T cells had become follicular helper T cells (Tfh). These are critical components of the immune system that help the body fight off viral and bacterial infections. Little was known, however, about how they impact atherosclerosis.

With further experiments, Gaddis and her colleagues established that Tfh cells promote atherosclerosis. By blocking the generation of Tfh cells, the scientists could reduce the development of plaques in the arteries of mice fed the Western diet.

The team next wanted to know whether HDL, which removes excess cholesterol from cells, might protect against atherosclerosis by preventing the loss of regulatory T cells. They tested this idea by administering the primary component of HDL, a protein called apolipoprotein AI, to their mice. With this treatment, regulatory T cells resisted the effects of the Western diet and did not change into Tfh cells.

Although it’s not yet known whether regulatory T cells undergo the same conversion in humans, the finding gives a clearer picture of how diet and the immune system interact to shape cardiovascular risk.

“With a western diet, protective cells change to damaging cells, causing more inflammation,” says Gaddis. “What we’re finding is that HDL- the good cholesterol- actually helps shield the protective cells against the damaging changes that occur during atherosclerosis plaque development.”​

Tagged with:

About author

Related Articles