Propionibacterium acnes and the Th1/Th17 Axis, Implications in Acne Pathogenesis and Treatment.

Acne vulgaris is one of the most commonly seen conditions and the immunological link is a topic of active research. Recently, the Th17 pathway has been found to play a pivotal role in acne. The adaptive immune response toward Propionibacterium acnes leads to activation of Th17 axis. Consequently, the Th17 cytokines (IL-17, IL-1 β, IL-6, and tumor growth factor, in turn, activate the various pathogenic steps in acne. Drugs such as Vitamin D3 and isotretinoin which target the Th17 pathway may offer an additional pathway for their therapeutic response.