Watch out, acne. Doctors soon may have a new weapon against
zits: a harmless virus living on our skin that naturally seeks out and kills
the bacteria that cause pimples.
The new findings by scientists at the University of California,
Los Angeles (UCLA) and the University of Pittsburgh are published online in mBio.
“Acne affects millions of people, yet we have few
treatments that are both safe and effective,” says principal investigator Robert
Modlin, chief of dermatology and a professor of microbiology, immunology, and
molecular genetics at the David Geffen School of Medicine at UCLA.
“Harnessing a virus that naturally preys on the bacteria that cause
pimples could offer a promising new tool against the physical and emotional
scars of severe acne.”
The scientists looked at two little microbes that share a big
name: Propionibacterium acnes, a bacterium thriving in our pores that
can trigger acne, and P. acnes phages, a family of viruses that live on
human skin. The viruses are harmless to humans but are programmed to infect and
kill the aforementioned P. acnes bacteria.
When P. acnes bacteria aggravate the immune system, it
causes the swollen, red bumps associated with acne. Most effective treatments
work by reducing the amount of P. acnes bacteria on the skin.
“We know that sex hormones, facial oil and the immune
system play a role in causing acne; however, a lot of research implicates P.
acnes as an important trigger,” explains first author Laura Marinelli,
a UCLA postdoctoral researcher in Modlin’s laboratory. “Sometimes they set
off an inflammatory response that contributes to the development of acne.”
Using over-the-counter pore-cleansing strips, the researchers
lifted acne bacteria and the P. acnes phages from the noses of both
pimply and clear-skinned volunteers.
When the team sequenced the phages’ genomes, they discovered that
the viruses possess multiple features—such as small size, limited diversity,
and the broad ability to kill their hosts—that make them ideal candidates for
the development of a new anti-acne therapy.
“Our findings provide valuable insights into acne and the
bacterium that causes it,” says corresponding author Graham Hatfull, Eberly
Family Professor of Biotechnology and professor of biological sciences at the
University of Pittsburgh and a Howard Hughes Medical Institute researcher.
“The lack of genetic diversity among the viruses that attack the acne
bacterium implies that viral-based strategies may help control this distressing
“Phages are programmed to target and kill specific
bacteria, so P. acnes phages will attack only P. acnes bacteria
but not others like E. coli,“ Marinelli adds. “This
trait suggests that they offer strong potential for targeted therapeutic
So why, if the phages naturally attack the P. acnes
bacteria, do people still get acne? One hypothesis, the researchers say, is
that those with healthy skin may have a population of phages that helps keep
the P. acnes bacteria in check, while in others, the phage activity
is insufficient to prevent the bacteria from aggravating the immune system.
Acne affects nearly 90 percent of Americans at some point in
their lives, yet scientists know little about what causes the disorder and have
made narrow progress in developing new strategies for treating it. Dermatologists’
arsenal of anti-acne tools—benzoyl peroxide, antibiotics, and Accutane—hasn’t
expanded in decades.
“Antibiotics such as tetracycline are so widely used that
many acne strains have developed resistance, and drugs like Accutane, while
effective, can produce risky side effects, limiting their use,” says
co-author Jenny Kim, director of the UCLA Clinic for Acne, Rosacea and
Aesthetics. “Acne can dramatically disfigure people and undermine their
self-esteem, especially in teens. We can change patients’ lives with treatment.
It’s time we identified a new way to safely treat the common disorder.”
The research team plans to isolate the active protein from the P.
acnes virus and test whether it is as effective as the whole virus in
killing acne bacteria. If laboratory testing proves successful, the researchers
will study the compound’s safety and effectiveness in combating acne in people.