Many of the current therapies focus on reducing the number of P. acnes organisms. and most recent developments have been in the use of combination therapies. Benzoyl peroxide and the retinoids have been added to topical antibiotics with the hope that the frequency of resistance will decrease, thereby improving the therapeutic outcome. On the other hand, only a few therapies focus primarily on reducing inflammation. Several previous studies have demonstrated that both cellular and humoral immunity against P. acnes are present in patients, and recent studies have provided a better understanding of the innate immune response produced by hosts in response to P. acnes. Upon activation, host innate cells elaborate a protective antimicrobial response to P. acnes by inducing the production of antimicrobial peptides such as human β-defensin 2. generated antibodies using inactivated P. acnes, postulating that they might provide protective immunity. intranasal immunization of mice with this inactivated vaccine generated in vivo protective immunity against P. acnes challenge. Specifically, the antibodies elicited by inactivated P. acnes attenuated IL-8 production in human sebocytes; however, there was no effect on P. acnes growth. The clinical improvement observed in this P. acnes inflammatory murine model suggests that for acne treatment, antibodies that primarily exhibit anti-inflammatory properties might be sufficient for clinical improvement but without an antimicrobial effect. The inactivated P. acnes vaccine used in this study targeted the whole bacterium, most likely without specificity. Therefore, developing vaccines against specific P. acnes antigens might be even more useful. study offer an important and interesting concept—that focusing on attenuating the inflammatory component of the disease could be therapeutically beneficial. Because the induction of cytokines, chemokines, and metalloproteinases by P. acnes occurs via a Toll-like receptor 2 (TLR2)-dependent pathway, the development of vaccines or other immune therapies that target TLR2 and other TLRs may provide other alternatives to conventional therapy.
