Vaccine triggers alarm to fight dust mite allergy
A new vaccine uses a booster normally found in cancer vaccines to combat dust-mite allergies by naturally switching the body’s immune response.
In animal tests, the nano-sized vaccine package lowered lung inflammation by 83 percent, despite repeated exposure.
“What is new about this is we have developed a vaccine against dust-mite allergens that hasn’t been used before,” says Aliasger Salem, professor in pharmaceutical sciences at University of Iowa and a corresponding author of the paper.
Ubiquitous, microscopic dust mites that burrow in mattresses, sofas, and other homey spots are found in 84 percent of households in the United States, according to a published, national survey.
Preying on skin cells on the body, the mites trigger allergies and breathing difficulties among 45 percent of those who suffer from asthma, according to some studies. Prolonged exposure can cause lung damage.
Treatment is limited to getting temporary relief from inhalers or undergoing regular exposure to build up tolerance, which is long term and holds no guarantee of success.
Alleviate mite-induced asthma
“Our research explores a novel approach to treating mite allergy in which specially-encapsulated miniscule particles are administered with sequences of bacterial DNA that direct the immune system to suppress allergic immune responses,” says Peter Thorne, public health professor and a contributing author of the paper. “This work suggests a way forward to alleviate mite-induced asthma in allergy sufferers.”
The vaccine takes advantage of the body’s natural inclination to defend itself against foreign bodies. A key to the formula lies in the use of an adjuvant—which boosts the potency of the vaccine—called CpG. The booster has been used successfully in cancer vaccines but never had been tested as a vaccine for dust-mite allergies.
Put broadly, CpG sets off a fire alarm within the body, springing immune cells into action. Those immune cells absorb the CpG and dispose of it.
This is important, because as the immune cells absorb CpG, they’re also taking in the vaccine, which has been added to the package, much like your mother may have wrapped a bitter pill around something tasty to get you to swallow it. In another twist, combining the antigen (the vaccine) and CpG causes the body to change its immune response, producing antibodies that dampen the damaging health effects dust-mite allergens generally cause.
In lab tests, the CpG-antigen package, at 300 nanometers in size, was absorbed 90 percent of the time by immune cells. Researchers followed up those experiments by giving the package to mice and exposing the animals to dust-mite allergens every other day for nine days total.
Packages with CpG yielded greater production of the desirable antibodies, while lung inflammation was lower than particles that did not contain CpG.
“This is exactly what we were hoping for,” Salem says.
First author of the paper, in the AAPS Journal, is Vijaya Joshi, a graduate fellow in pharmacy. The National Institutes of Health and the American Cancer Society partly funded the research.
Source: University of Iowa