TY - JOUR
T1 - Systemic isotretinoin therapy normalizes exaggerated TLR-2-mediated innate immune responses in acne patients
AU - Dispenza, Melanie C.
AU - Wolpert, Ellen B.
AU - Gilliland, Kathryn L.
AU - Dai, Jenny P.
AU - Cong, Zhaoyuan
AU - Nelson, Amanda M.
AU - Thiboutot, Diane M.
N1 - Funding Information:
We thank Dr David Stanford and Nate Sheaffer in the PSU Hershey Flow Cytometry Core for their technical assistance. This work was supported by the American Acne and Rosacea Society Clinical Research Grant to MCD, the Penn State University Finkelstein Memorial Student Research Award to MCD, the Penn State Hershey Department of Dermatology, NIH grant RO1 AR047820 to DMT, and the Jake Gittlen Cancer Research Foundation. Core Facility services and instruments used in this project were funded, in part, under a grant with the Pennsylvania Department of Health using Tobacco Settlement Funds. The Department specifically disclaims responsibility for any analyses, interpretations, or conclusions.
PY - 2012/9
Y1 - 2012/9
N2 - Retinoids are used in the treatment of inflammatory skin diseases and malignancies, but studies characterizing the in vivo actions of these drugs in humans are lacking. Isotretinoin is a pro-drug for all-trans retinoic acid, which can induce long-term remissions of acne; however, its complete mechanism of action is unknown. We hypothesized that isotretinoin induces remission of acne by normalizing the innate immune response to the commensal bacterium Propionibacterium acnes. Compared with normal subjects, peripheral blood monocytes from acne patients expressed significantly higher levels of Toll-like receptor 2 (TLR-2) and exhibited significantly greater induction of TLR-2 expression following P. acnes stimulation. Treatment of patients with isotretinoin significantly decreased monocyte TLR-2 expression and subsequent inflammatory cytokine response to P. acnes after 1 week of therapy. This effect was sustained 6 months following cessation of therapy, indicating that TLR-2 modulation may be involved in the durable therapeutic response to isotretinoin. This study demonstrates that isotretinoin exerts immunomodulatory effects in patients and sheds light on a potential mechanism for its long-term effects on acne. The modulation of TLR-2 expression on monocytes has important implications in other inflammatory disorders characterized by TLR-2 dysregulation.
AB - Retinoids are used in the treatment of inflammatory skin diseases and malignancies, but studies characterizing the in vivo actions of these drugs in humans are lacking. Isotretinoin is a pro-drug for all-trans retinoic acid, which can induce long-term remissions of acne; however, its complete mechanism of action is unknown. We hypothesized that isotretinoin induces remission of acne by normalizing the innate immune response to the commensal bacterium Propionibacterium acnes. Compared with normal subjects, peripheral blood monocytes from acne patients expressed significantly higher levels of Toll-like receptor 2 (TLR-2) and exhibited significantly greater induction of TLR-2 expression following P. acnes stimulation. Treatment of patients with isotretinoin significantly decreased monocyte TLR-2 expression and subsequent inflammatory cytokine response to P. acnes after 1 week of therapy. This effect was sustained 6 months following cessation of therapy, indicating that TLR-2 modulation may be involved in the durable therapeutic response to isotretinoin. This study demonstrates that isotretinoin exerts immunomodulatory effects in patients and sheds light on a potential mechanism for its long-term effects on acne. The modulation of TLR-2 expression on monocytes has important implications in other inflammatory disorders characterized by TLR-2 dysregulation.
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U2 - 10.1038/jid.2012.111
DO - 10.1038/jid.2012.111
M3 - Article
C2 - 22513780
AN - SCOPUS:84865313629
SN - 0022-202X
VL - 132
SP - 2198
EP - 2205
JO - Journal of Investigative Dermatology
JF - Journal of Investigative Dermatology
IS - 9
ER -