immune system

Children’s food allergies related to immunosuppression

Food allergies affect around 15 million Americans, including many children. Symptoms of allergies and intolerance can range from relatively minor, such as a harmless skin rash, to potentially fatal anaphylactic shock.

Many individuals outgrow their allergy as they reach adulthood. This is thought to be due to the immune system learning to tolerate food that it previously perceived as “foreign.”

Researchers from La Jolla Institute for Allergy and Immunology (LJI) in San Diego, CA, led by Charles Surh, PhD, wanted to explain why children, who have more limited exposure to novel foods than adults, are more prone to food allergies.

They hypothesized that consuming a normal diet would stimulate cells in the gut that prevent the immune system from rejecting food.

Food and pathogens both display macro molecular markers known as antigens. These antigens announce to the immune system that a food is “foreign.”

Mouse studies have previously looked at how the body would distinguish antigenic “friend” from “foe.”

The mice were fed with an egg protein that they had not eaten before. Researchers observed that an immunosuppresive cell, called a Treg cell, was produced in the gut. These Treg cells blocked the immune response to the new substances.

It was not known if this would happen when young mammals encountered new foods in “real life.”

Surh used “antigen-free” mouse models to represent an immunological blank slate. The mice were raised in a germ-free environment. They were also fed a diet of amino acids, the building blocks of proteins, instead of foods that contain the proteins themselves.

This made the mice “immunologically naïve,” because amino acid building blocks are not big enough for the immune system to recognize them. It meant that the mice had little or no previous contact with antigenic proteins and other macromolecules.

Other mice were germ free but fed on a normal diet.

Molecular marker analysis revealed that the mice that consumed amino acids had no Tregs in the small intestine. In contrast, mice that were fed a normal protein diet had a large number of Tregs.

This suggests that when proteins are contained in food, they stimulate Treg development. It also indicates that Tregs in the gut of normal mice might serve to prevent a potentially disastrous immune response to those proteins.

The researchers also demonstrated that food and beneficial bacteria in the gut generate different types of Tregs.

Germ-free mice appear to have only food-dependent Tregs and lack the kind of Tregs that are induced by healthy microbes. These mice are also known to be very susceptible to allergies.

The scientists deduced that to prevent allergic symptoms, the gut needs both food- and microbe-induced Tregs.

Source: medicalnews today

Research reveals how Ebola virus blocks immune system

The Ebola virus, in the midst of its biggest outbreak on record, is a master at evading the body’s immune system. But researchers at Washington University School of Medicine in St. Louis and elsewhere have learned one way the virus dodges the body’s antiviral defenses, providing important insight that could lead to new therapies.

Research reveals how Ebola virus blocks immune system

The virus has infected about 1,800 people since March in four West African nations and killed more than half of them, according to the World Health Organization.

The researchers developed a detailed map of how an Ebola protein, VP24, binds to a host protein that takes signaling molecules in and out of the cell nucleus. Their map revealed that the viral protein takes away the host protein’s ability to carry an important immune signal into the nucleus.

This signal helps activate the immune system’s antiviral defenses, and blocking it is believed to contribute significantly to the virus’s deadliness.

“We’ve known for a long time that infection with Ebola obstructs an important arm in our immune system that is activated by molecules called interferons,” said senior author Gaya Amarasinghe, PhD, assistant professor of pathology and immunology at the School of Medicine. “Now that our map of the combined structure of these two proteins has revealed one critical way Ebola does this, the information it provides will guide the development of new treatments.”

The results appear Aug. 13 in Cell Host & Microbe.

A National Institutes of Health (NIH) grant of up to $15 million, awarded March 1, is helping Amarasinghe and other researchers look for drugs to block VP24 and another Ebola protein, VP35. The group includes researchers at the Icahn School of Medicine at Mount Sinai, Washington University, the University of Texas Southwestern Medical Center, Howard University and Microbiotix Inc., a Massachussetts biopharmaceutical company.

Co-author Christopher Basler, PhD, professor of microbiology at Mount Sinai and the principal investigator of the consortium, was the first to show that VP24 and VP35 were important to the virus’s ability to keep the immune system at bay.

In an earlier paper, Amarasinghe, Basler and others revealed that VP35 blocks production of interferon, one of the main regulators of the innate immune system. This branch of the immune system specializes in fighting viruses.

“Interferon is critical to our ability to defend ourselves against viruses,” Basler said. “It makes a variety of responses to viral infection possible, including the self-destruction of infected cells and the blockage of supplies necessary for viral reproduction.”

In the new study, Amarasinghe and Daisy Leung, PhD, assistant professor of pathology and immunology at Washington University, showed that VP24 tightly binds to a nuclear transporter, a protein that takes molecules into and out of the cell nucleus. Among the molecules these transporters take into the nucleus is STAT1, an important component of the interferon signaling pathway.

“Normally STAT1 is transported into the nucleus and activates the genes for hundreds of proteins involved in antiviral responses,” Leung said. “But when VP24 is attached to some of these transporters, STAT1 can’t get into the nucleus.”

The researchers found that VP24’s action specifically prevents STAT1 transport. Other proteins that travel in and out of the cell nucleus and are important to viral replication likely are unaffected. The scientists already have initiated efforts to look for small molecules that block VP35 and now are applying those same approaches to VP24.

Source: washington university

Why Stress Is Bad for Your Health

Why Stress Is Bad for Your Health

Not Just in Your Head

You don’t need a doctor to tell you that anxiety can have a negative effect on your health. But do you really know the toll that long-term stress can take?

Stress is the body’s reaction to something that taxes or exceeds its resources, says Frances Cohen, a psychologist at the University of California, San Francisco. When we perceive something as harmful, our brain triggers hormones such as cortisol, which flood the body and contribute to various physical responses.

Here are several ways stress can affect different aspects of your health — and how you can protect yourself against them.

Lack of Sleep

Anxiety is one of the main causes of insomnia and sleep disruption: When you think about something stressful while lying in bed, it’s harder for your body to relax and drift off to dreamland — and this nightly pattern only gets worse as your brain and body learn to dread bedtime.

You may also be deliberately robbing yourself of much-needed rest by staying up too late or rising too early: Most of us need seven to nine hours of sleep a night, but many overscheduled and overworked adults regularly get by on less. Skimping on sleep can cause fatigue and attention problems, and increase your risk of disease.

Weakened Immune System

We’ve all experienced the nasty cold that comes after a deadline — a reminder that psychological stress can weaken defenses and make us more susceptible to germs. It can also slow our recovery from illnesses; in fact, research has shown that stress hormones actually make immune cells age faster.

It’s not just minor ailments to which stress leaves us vulnerable, either: Consistently high levels of stress can reduce a woman’s ability to fight infections such as human papilloma virus (HPV), which can cause cervical cancer.

Low-Level Inflammation

Whether you scrape your knee, twist your ankle, or succumb to strep throat, the body’s reaction is the same: The immune system sends in white blood cells to destroy bacteria and repair the tissue, causing redness, swelling, and warmth. This healing process, called the inflammatory response, is one of the body’s most basic survival instincts.
But when bombarded by unrelenting stress, the immune system works overtime, releasing a stream of inflammation-promoting compounds that spread throughout the body, damaging cells and tissues. If left unchecked, low-level inflammation can simmer for years, contributing to a range of seemingly unrelated ailments such as heart disease, asthma, and cancers.
High Blood Pressure

Stress and anxiety stimulate your nervous system to raise levels of hormones like adrenaline and cortisol, which narrow blood vessels and therefore increase your risk of developing hypertension. Only about a third of people with hypertension (blood pressure higher than 140/90) know they have it — even though it affects around one in three American adults.
The condition can be bad news if left untreated, raising your risk of such ailments as heart attack, stroke, kidney failure, and blindness. Fortunately, eating a balanced diet and exercising regularly — and learning to stress less — can help you stay healthy.

Blemishes and Wrinkles

Just as inflammation can have a negative effect on your long-term health, it can also have a physical — and much more immediate — effect on your appearance. Stress and fatigue can lead to puffy skin and a blotchy complexion, dark circles under the eyes, and early wrinkles. Hormones triggered by stress can also cause breakouts well into adulthood.

In addition to getting enough sleep and reducing stress levels, you can calm redness and blemishes with serums and gels that contain extracts of anti-inflammatory herbs like chamomile, calendula, and lavender

Aches and Pains

Millions of us work at desks every day, and our bodies pay the price. From stiff necks and tension headaches to throbbing backs, head-to-toe pain can result from staring at a computer for hours on end — and when you’re stressed about your job, you’re less likely to take frequent breaks and more likely to overdo it.

Inflammation caused by stress has also been linked to migraines and rheumatoid arthritis, two chronic pain conditions that may improve with stress-reduction techniques.

Mental Health

Trying to do too much at once — whether it’s work assignments, family obligations, or social appointments — can leave you feeling burned out and empty inside. 817132d7edd2b285_stress.xxxlarge
Too often, when stressors start to pile up, the first things we push aside are the ones that can help us cope: quailty time with friends and family, alone time for reflection and enjoyment, a good night’s sleep, and regular exercise. These activities help our brains and bodies cope with the harmful effects of stress, and without them to keep us grounded, it’s easy to spin out of control.
Substance Abuse

When you’re juggling the multiple responsibilities of work and home, being frazzled can start to feel normal. Many people have never learned healthy ways of dealing with stress, instead turning to alcohol or nicotine.

Weight Gain

Stress, fatigue, and weight gain are common companions: Sleep deprivation can cue your body to release stress hormones, triggering weight gain. Studies have shown that those who sleep fewer than eight hours a night have higher body mass than people who sleep a full eight hours, and that babies who sleep fewer than 12 hours a day are twice as likely to be overweight by age 3.

Meanwhile, stress can also lead to poor food choices; this can put your body on a blood-sugar roller coaster, which causes low energy (and, in turn, makes it even harder to get to the gym or outside for a walk). And the less time you have to take care of yourself, the harder it is to make healthy changes.

Infertility

Infertility is a medical condition used to describe couples who have tried unsuccessfully to conceive for 12 months. By the time a woman or a couple receives this label, they’re often highly stressed, says Tracy Gaudet, M.D., director of Duke Integrative Medicine at Duke University — which only makes matters worse. (Read Dr. Gaudet’s guide to coping with infertility.)

The higher a woman’s stress level, the lower her fertility. Highly stressed women can stop ovulating altogether, which makes sense biologically: In the hunter-gatherer days, stress probably indicated a lack of food or an imminent threat — not wise times to bring an infant into the world

Low Libido

There are quite a few external causes of low libido and tension between you and your partner, and many of them have to do with stress. The first year or two after the birth of a baby, for instance, when both parents are often overwhelmed and sleep-deprived, is a notorious libido killer. Career-focused years can leave women depleted and stressed, with all of their passion going into their jobs. And chronic stress can lead to depression, also a cause of plummeting desire.

Gastrointestinal Issues

That feeling of butterflies in your stomach may very well have a physiological basis: Your GI tract has its own nervous system, which is why stress can cause digestive problems such as diarrhea, heartburn, and irritable bowel syndrome (IBS). Learn to manage stress — and reduce GI problems — by exploring massage, art therapy, breathing exercises, and other relaxation techniques.

Self-Fulfilling Pessimism

There’s nothing wrong with considering the potential pitfalls of your current situation — for a little while. It’s smart to anticipate and plan for how you’ll handle a given obstacle.
But endlessly stressing over what might go wrong often proves more than unproductive. It can actually set you up for the very thing you fear the most. When you visualize a negative outcome, you approach things differently. You operate, ironically, in a way that supports the result you most want to avoid.

Source: Whole living

Poor sleep speeds cancer growth

Poor-quality sleep marked by frequent awakenings can speed cancer growth and increase tumour aggressiveness, a new study has warned.

The study is the first to demonstrate, in an animal model, the direct effects of fragmented sleep on tumour growth and invasiveness.

“Fragmented sleep changes how the immune system deals with cancer in ways that make the disease more aggressive,” said study director David Gozal, chairman of pediatrics at the University of Chicago Comer Children’s Hospital.

“Fortunately, our study also points to a potential drug target,” he said.

“Toll-like receptor 4, a biological messenger, helps control activation of the innate immune system. It appears to be a lynchpin for the cancer-promoting effects of sleep loss. The effects of fragmented sleep that we focused on were not seen in mice that lacked this protein,” Gozal said.

Gozal and colleagues from the University of Chicago and the University of Louisville devised a series of experiments to measure the effects of disrupted sleep on cancer.

They used mice, housed in small groups. During the day – when mice normally sleep – a quiet, motorised brush moved through half of the cages every two minutes, forcing those mice to wake up and then go back to sleep. The rest of the mice were not disturbed.

After seven days in this setting, both groups of mice were injected with cells from one of two tumour types (TC-1 or 3LLC). All mice developed palpable tumours within 9 to 12 days. Four weeks after inoculation the researchers evaluated the tumours.

They found that tumours from mice with fragmented sleep were twice as large, for both tumour types, than those from mice that had slept normally.

A follow-up experiment found that when tumour cells were implanted in the thigh muscle, which should help contain growth, the tumours were much more aggressive and invaded surrounding tissues in mice with disrupted sleep.

The difference appeared to be driven by cells from the immune system, called tumour-associated macrophages (TAMs), which cluster at the site of tumours.

TAMs are a hallmark of the immune system’s response to cancer. Some, labelled M1, promote a strong immune response and can eliminate tumours cells. Others, known as M2, suppress the immune response and instead promote the growth of new blood vessels – which encourages tumour growth.

Well-rested mice had primarily M1-type TAMs, concentrated in the core of the tumours. Sleep-fragmented mice had primarily M2-type TAMs, researchers said.

The study was published in the journal Cancer Research.

Source: Zee news

Fibre rich diet may ward off asthma

A new study has revealed that eating a diet rich in fibre can protect against allergic asthma by triggering changes in the immune system.

Benjamin Marsland from the University Hospital of Lausanne in Switzerland and colleagues found that levels of dietary fibre, found in fruit and vegetables, can influence the balance of microbes in the gut in ways that make the airways more or less prone to the inflammation seen in allergic airway diseases, New Scientist reported.

The researchers, who looked at how the immune and inflammatory responses of mice varied with the fibre in their diet, found that when the mice were exposed to an extract of house dust mites, those fed with less fibre had double the number of a specific type of immune cell associated with asthmatic inflammation in their airways, than those on a standard diet.

It was found that mice given additional fibre supplements on top of a standard diet showed a reduction in these immune cells, but only if the supplement was easily fermentable in the gut.

The study was published in Journal Nature Medicine.

Source:  Zee news

Foods with Zinc can fight Diabetes Mellitus

Diabetes is an escalating issue in the United States, and there are no signs of this health ailment diminishing. According to the American Diabetes Association, 23.6 million adults and children have diabetes in the U.S. That is 7.8% of the population according to the latest data formed from 2007, and 1.6 million new cases are diagnosed each year. Luckily, there are many natural remedies that may aid in suppressing the negative effects of diabetes. Many of these remedies may completely cure or prevent diabetes when used properly.

Research shows that zinc, an essential trace element responsible for more than 300 enzyme functions, can aid in normalizing the negative effects of diabetes mellitus. According to the study, zinc has been shown to mitigate the harmful effects of diabetes by improving glycemic control in type I and type II diabetes. Many of the enzyme systems in which zinc is a necessity for are involved with the metabolism of blood sugar, and therefore make zinc a natural catalyst for insulin secretion.

The pancreas is an endocrine gland responsible for producing hormones like glucagon, somatostatin, and–you guessed it–insulin. The beta cells that secrete insulin in your pancreas are also highly stored with zinc. Without the high concentrations of zinc, the beta cells suffer. Luckily, beta cells are equipped with their own special transporter called ‘zinc transporter 80, which makes it easy for the beta cells to store the zinc. However, it is known that any metamorphosis of the genes in the zinc transporter 8 causes type 2 diabetes. It is also now known that antibodies against the zinc transporter are present in type 1 diabetic patients, which means that these antibodies are associated with type 1 diabetes.

It is no wonder why zinc is as popular as it is for supplementation. In addition to mending the difficulties brought on by diabetes, zinc also serves to maintain a healthy immune system, controls hair loss, halts impotence, improves brain function, prevents loss of taste or smell, and much more. Although supplementation is a viable option to obtain the amount of zinc that you need, it is not the only option thanks to the abundant amount of foods rich in zinc that are available to the general public. To reap the many benefits of zinc, one could include any of the following foods into their diet:

Wheat Germ
Sesame Flour and Tahini
Low Fat Roast Beef
Roasted Pumpkin and Squash Seeds
Dried Water Melon Seeds
Cocoa Powder and Chocolate
Peanuts
Almonds
Avocado
Bananas
Cashew
Cheese
Chickpeas (including hummus and falafel)
Crab, Dungeness
Cucumber
Fish
Kiwi Fruit
Lettuce
Lima Beans
Olives
Onion

Source: Information center