An international team of skin researchers have gotten one step closer to achieving a holy grail of dermatology: a vaccine against acne. In a series of experiments in mice and isolated human tissue, the scientists showed that the use of lab-created antibodies to target a toxin produced by the P. acnes bacteria can prevent the inflammatory response that leads to the development of the self-esteem shattering lesions.
As of now, acne is either treated with long-term regimens of topical medications with inconsistent efficacy or oral medications with intense side effects, and no agents are known to prevent its occurrence.
"Once validated by a large-scale clinical trial, the potential impact of our findings is huge for the hundreds of millions of individuals suffering from acne vulgaris," lead investigator Chun-Ming Huang said in a statement. "Current treatment options are often not effective or tolerable for many of the 85 percent of adolescents and more than 40 million adults in the United States who suffer from this multi-factorial cutaneous inflammatory condition. New, safe, and efficient therapies are sorely needed."
Previous research by the group had shown that a toxic protein secreted by P. acnes, called CAMP factor, contributes to the inflammation pathway that results in pimples, papules, nodules, and cysts. In addition, past work in mice has indicated that vaccines composed of P. acnes surface proteins, entire heat-killed bacterium, or E.coli that overexpress CAMP factor could protect against the development of acne.
In the latest investigation, detailed in the Journal of Investigative Dermatology, Huang and his colleagues sought to confirm that CAMP factor is the main driving force of inflammatory acne in humans and to explore whether a vaccine approach might hold promise. The results in mice indicate that monoclonal antibodies against CAMP factor 2, a version of the toxin that appears to occur in all five human P. acnes strains, considerably reduced the growth of the bacteria on the animals’ skin and lowered expression of an inflammatory signaling molecule called interleukin 8 (IL-8).
Furthermore, acne lesions taken from human patients that were treated with CAMP factor 2 antibodies showed significant reductions in IL-8 and another, similar molecule called IL-1β. This finding supports the theory that “P. acnes CAMP factor is an essential source of inflammation in acne vulgaris,” according to the authors.
Now that a suitable antigen has been identified, the team hope to create a formulation that is safe for use in humans. If successful, they predict that a vaccine or other type of inhibitory drug could also be used for other P. acnes-associated diseases, including prostate cancers, sepsis, toxic shock syndrome, heart infections, bone infections, and various post-surgery infections. One concern that will need to be investigated, however, is whether CAMP factor 2 antibodies will react with other compounds and/or bacteria found in the skin, including those that are beneficial.
"While addressing an unmet medical need and providing an appealing approach, acne immunotherapies that target P. acnes-derived factors have to be cautiously designed to avoid unwanted disturbance of the microbiome that guarantees skin homeostasis," dermatologist Emmanuel Contassot wrote in an accompanying commentary. “[B]ut acne immunotherapy presents an interesting avenue to explore nonetheless."