The role of "Propionbacterium Acnes" in Acne

Propionibacterium acnes: an update on its role in the pathogenesis of acne.

Beylot C, Auffret N, Poli F, Claudel JP, Leccia MT, Del Giudice P, Dreno B.

J Eur Acad Dermatol Venereol. 2014 Mar;28(3):271-8. doi: 10.1111/jdv.12224. Epub 2013 Aug 1.

P. acnes is a bacteria whic has a strong proinflammatory activity and targets molecules involved in the innate cutaneous immunity, keratinocytes and sebaceous glands of the pilosebaceous follicle.

1. Effects of Propinibacterium Acnes on pathogenesis

• Diferent mediators cytokines play a role based on their targets:

1. Keratinocytes: inflammation (indirect effect of ROS (reactive oxygen species), Il-8, cytokine P1, HBD2, MMP (matrix metalloproteinases) and hyperkeratinization (direct effect IGF (Insulin Growth factor) and IGF-1, Il1 alpha, Transglutaminases, integrins, filaggrin, up regulation of the following keratins: K1,  K10,  K17, down regulation of K6 and 16)
2. Sebaceous glands: (direct effect on lipognesis through upregulation of CRH (Corticotropin releasing hormone), CRH1, IGF, IGF-R) lead to Hyperseborrhea

2. Therapeutical perspectives

• A. Target therapy against innate immunity receptors (TLR (Toll-like receptors) and PAR (Protease-activated receptors)

1. TLR which is modulated by systemic retinoids and systemic zinc. Benzoyle peroxide and Adapalene have been shown to down regulate TLR2
2. PAR (Protease-activated receptors)

• B. Antimicrobial peptides (AMP) like canthelicidines.

1. Canthelicidins BF is purified from snake venom and acts against P Acnes and S.Aureus.
2. Also vaccines could be developed which would target:
   1. Sialidase on the membrane of the bacterium: protein which enhances cytotoxicity and adhesion
   2. CAMP factor secretory protein which is cytotoxic to keratinocytes and macrophages

Conflict of interest: Galderma Laboratories