Dimerized Translationally Controlled Tumor Protein-Binding Peptide Ameliorates Atopic Dermatitis in NC/Nga Mice

Our previous study showed that dimerized translationally controlled tumor protein (dTCTP) plays a role in the pathogenesis of allergic diseases, such as asthma and allergic rhinitis. A 7-mer peptide, called dTCTP-binding peptide 2 (dTBP2), binds to dTCTP and inhibits its cytokine-like effects. We therefore examined the protective effects of dTBP2 in house dust mite-induced atopic dermatitis (AD)-like skin lesions in Nishiki-nezumi Cinnamon/Nagoya (NC/Nga) mice. We found that topical administration of dTBP2 significantly reduced the AD-like skin lesions formation and mast cell infiltration in NC/Nga mice, similarly to the response seen in the Protopic (tacrolimus)-treated group. Treatment with dTBP2 also decreased the serum levels of IgE and reduced IL-17A content in skin lesions and inhibited the expression of mRNAs of interleukin IL-4, IL-5, IL-6, IL-13, macrophage-derived chemokine (MDC), thymus and activation-regulated chemokine (TARC) and thymic stromal lymphopoietin (TSLP). These findings indicate that dTBP2 not only inhibits the release of Th2 cytokine but also suppresses the production of proinflammatory cytokines in AD-like skin lesions in NC/Nga mice, by inhibiting TCTP dimer, in allergic responses. Therefore, dTCTP is a therapeutic target for AD and dTBP2 appears to have a potential role in the treatment of AD.