Original article Tacrolimus does not alter the production of several cytokines and antimicrobial peptide in Malassezia furfur-infected-keratinocytes Anna Balato, 1 Iole Paoletti, 2 Vincenza De Gregorio, 2 Mariateresa Cantelli, 1 Fabio Ayala 1 and Giovanna Donnarumma 2 1 Department of Dermatology, University of Naples Federico II, Naples, Italy and 2 Department of Experimental Medicine, Section of Microbiology and Clinical Microbiology, Second University of Naples, Naples, Italy Summary Topical immunosuppressant therapy is widely used in the treatment of inflammatory skin diseases, such as atopic dermatitis and psoriasis. Besides its beneficial therapeu- tic effects, application of topical anti-inflammatory drugs may render the epidermis more vulnerable to invading pathogens by suppressing innate immune responses in keratinocytes (KCs). Cytokines, chemokines and antimicrobial peptides (AMPs) pro- duced by epithelial cells enable them to participate in innate and acquired immune responses. The aim of the present work was to study the influence of tacrolimus (FK506) on KCs infected with Malassezia furfur (M. furfur), evaluating the expression of pro-inflammatory cytokines IL-1a and IL-6, chemokine IL-8, anti-inflammatory cytokines transforming growth factor beta1 (TGF-b1) and IL-10 and AMP b-defen- sin-2. Human KCs were obtained from surgical specimens of normal adult skin. The expression of mRNAs in KCs: FK506-treated, FK506-treated and M. furfur-infected as well as only M. furfur-infected was quantified by real-time quantitative polymerase chain reaction. Next, the production of the AMP b-defensin-2 and of the above-men- tioned pro-inflammatory and anti-inflammatory cytokines was evaluated using enzyme-linked immunosorbent assay. In this study, FK506 did not alter cytokine and AMP production by KCs; this led us to hypothesise that it may not enhance the risk of mycotic skin infections. Key words: FK506, human beta-defensin-2, Malassezia furfur, mycotic infections. Introduction Tacrolimus (FK506), a macrolide isolated from Strepto- myces tsukubaensis, 1 exerts potent immunosuppressive effects in a variety of in vitro and in vivo systems; 2–4 in fact, it is used to prevent graft rejection after organ transplantation in animals and human beings. 5–8 Regarding cutaneous diseases, FK506 ointment has been used successfully in chronic inflammatory dermatoses, such as atopic dermatitis and psoriasis. 9–12 FK506 inhibits the calcium-dependent phosphatase calcineurin, an enzyme required for the dephosphoryla- tion of activated T cells nuclear factor cytosolic form. Therefore, the therapeutic efficacy of FK506 has been attributed to its impact on T-cell activation, making it effective for the treatment of inflammatory skin disorders. 13,14 Although FK506 ointment improves skin manifesta- tions in both psoriasis and atopic dermatitis, little has been done to investigate the possible interactions between FK506 and keratinocytes (KCs). Cytokines, chemokines and antimicrobial peptides (AMPs) produced by epithelial cells enable them to participate in innate and acquired immune responses. 15–19 Among AMPs, b-defensins, originally isolated from lesional psoriatic skin, constitute an Correspondence: A. Balato, Department of Dermatology, University of Naples Federico II, Via S. Pansini n.5, 80131 Napoli, Italy. Tel.: +39 081 7462457. Fax: +39 081 7462442. E-mail: annabalato@yahoo.it Submitted for publication 11 May 2013 Revised 22 July 2013 Accepted for publication 16 August 2013 © 2013 Blackwell Verlag GmbH doi:10.1111/myc.12140 mycoses Diagnosis,Therapy and Prophylaxis of Fungal Diseases