Blog – Page 10346

The lives of contact lens wearers just got a whole lot easier.

On Tuesday, the U.S. Food and Drug Administration approved the first contact lenses that can act like sunglasses.

A special additive automatically darkens the lenses when exposed to bright light, while they become clear again in normal or dark lighting conditions.

In a world first, scientists from Sydney’s Garvan Institute of Medical Research have revealed how a population of ‘bad’ antibodies in the immune system — which are usually ‘silenced’ because they can harm the body — can provide crucial protection against invading microbes. The research was carried out in mice.

The ‘bad’ antibodies are known to react against the body’s own tissues and can cause autoimmune disease. For this reason, it was once thought that they were discarded by the immune system or that they were made inactive in the long term. However, the new findings show for the first time that ‘bad’ antibodies go through a rapid ‘redemption’ process and are activated when the body is faced with a disease threat that other antibodies cannot tackle.

As a result, the ‘redeemed’ antibodies no longer threaten the body, but instead become powerful weapons to fight disease — and particularly diseases that evade the immune system by disguising themselves to look like normal body tissue.

In the disease atherosclerosis, cholesterol-containing plaques form in vessel walls, causing arteries to narrow and greatly increasing the risk of heart attack and stroke. Currently, atherosclerosis is the number 1 killer worldwide, just ahead of cancer. Recent use of statin anti-cholesterol drugs has reduced cardiovascular events caused by atherosclerosis by 35%, but millions of individuals remain at risk. Hence, a desirable addition or alternative would be intervention to prevent plaque formation altogether.

A new paper published in Circulation by researchers at La Jolla Institute for Allergy and Immunology supports this possibility. It reports successful vaccination of atherosclerotic mice with a small chunk of protein snipped out of “bad cholesterol.” Vaccination reduced plaque levels in test mice, and other experiments with human blood samples identified the class of T cells likely responsible for positive outcomes. The paper suggests that a comparable strategy could form the basis of a human vaccine.

“We knew atherosclerosis had an inflammatory component but until recently didn’t have a way to counteract that,” says senior author Klaus Ley, M.D., professor and head of LJI’s Division of Inflammation Biology. “We now find that our vaccination actually decreases plaque burden by expanding a class of protective T cells that curb inflammation.”