12:35 23 September 2011 by Debora MacKenzie
First it was smallpox. Then polio. Now science has another of humanity’s scourges in its sights: acne.
Acne is no joke. “More than 85 per cent of teenagers and over 40 million people in the United States alone are suffering this disease” and many adults have it too, says Chun-Ming Huang, head of the lab at the centre of the deal.
Yet there is little effective treatment, says Huang. “This collaboration will make our dreams of acne vaccines for the public come true earlier.”
Benign bug turns nasty
Pimples develop when oil-producing sebaceous glands in the skin become clogged. As the oxygen level within the pore falls, some of its otherwise benign bacterial inhabitants turn nasty and start killing skin cells to break into the blood. In response the immune system unleashes local inflammation, bringing in white blood cells and germ-killing chemicals to battle the bacteria – creating a pimple.
The chief culprit is the main bacterium in sebaceous glands, Propionibacterium acnes. Current acne treatments, such as benzoyl peroxide and antibiotics, aim to kill the bacterium. But acne can be chronic, and long-term use of antibiotics can lead to drug resistance in P. acnes, while other antibacterials damage the skin – partly by killing off its normal bacteria.
A major obstacle in acne research has been the lack of test animals – mice and guinea pigs don’t get spots. Huang’s lab got round that by injecting P. acnes into the skin of a mouse’s ear, causing inflammation. In 2008 they reported that mice given simple nasal-spray vaccines containing whole, dead P. acnes, or a protein from its surface, showed reduced ear inflammation compared to unvaccinated mice when they were then given a live bacterial injection.
This showed that antibodies to P. acnes might reduce pimples. However, a stable community of normal skin bacteria is known to protects the skin from colonisation by nastier germs. A vaccine that encourages the body to indiscriminately attack P. acnes could cause worse trouble than acne.