Anti-IL-17A and IL-23p19 antibodies but not anti-TNFα antibody induce expansion of regulatory T cells and restoration of their suppressive function in imiquimod-induced psoriasiform dermatitis.

Psoriasis is a chronic inflammatory skin disease. Anti-TNFα, IL-17A and IL-23p19 antibodies are effective for psoriasis. However, the contribution of regulatory T cells (Treg) in their effectiveness remains to be elucidated. We investigated the effects of TNFα, IL-17A and IL-23p19 inhibition on Tregs in imiquimod-induced psoriasiform dermatitis. Psoriasiform dermatitis was induced by imiquimod application on murine shaved back skin for six days. Mice were treated with anti-TNFα, IL-17A or IL-23p19 monoclonal antibodies every other day from one day before imiquimod application. Administration of anti-TNFα, IL-17A or IL-23p19 antibodies improved the clinical score and downregulated Th17-related cytokines and chemokines, while IL-23p19 antibodies upregulated IL-10 mRNA expression. Anti-IL-17A or IL-23p19 antibody-treated imiquimod-applied mice showed a significant increase in the number of Foxp3+ IL-10+ Tregs. Recipient mice adoptively transferred with Tregs derived from donor mice treated with antibodies demonstrated clinical and pathological improvement in imiquimod-induced psoriasiform dermatitis. Anti-IL-17A or IL-23p19 antibody-induced Tregs significantly increased the number of Foxp3+ cells and IL-10 expression in imiquimod-induced psoriasiform dermatitis in recipient mice but anti-TNFα antibody-induced Tregs did not. Anti-IL-17A or IL-23p19 antibody inhibits the IL-17/IL-23 signaling pathway, and induces expansion of Tregs and their suppressive capacity in imiquimod-induced psoriasiform dermatitis.

Shimizu T ，Kamata M ，Fukaya S ，Hayashi K ，Fukuyasu A ，Tanaka T ，Ishikawa T ，Ohnishi T ，Tada Y ... -  《-》

The vitamin D(3) analog, maxacalcitol, reduces psoriasiform skin inflammation by inducing regulatory T cells and downregulating IL-23 and IL-17 production.

Psoriasis is a Th1/Th17-mediated inflammatory dermatosis treated with topical corticosteroids and vitamin D3 analogs (VD3 As). To compare the effects of a VD3 A maxacalcitol and betamethasone valerate (BV) steroid lotion on topical imiquimod (IMQ)-induced psoriasiform skin inflammation. Female BALB/c mice were treated with vehicle, maxacalcitol or BV lotion on the skin for 3 days, and IMQ cream for 6 days. q-PCR, H&E, immunohistochemistry and immunofluorescence studies were performed on skin samples. Additionally, mice were treated with vehicle, maxacalcitol or BV lotion for 3 days and CD4+CD25+ regulatory T cells (Tregs) and CD4+CD25- cells from each group were isolated from lymph nodes. Adoptive transfer of the cells was performed on recipient mice which were treated with IMQ cream for 6 days, and skin samples were obtained for q-PCR and H&E staining. Maxacalcitol and BV were comparable in regards clinical improvement, although maxacalcitol reduced the MHC Class II+ inflammatory cell infiltration more than BV in IMQ skin. While both treatments downregulated IL-17 A, IL-17 F, IL-22, IL-12p40, TNF-α and IL-6 mRNA expression levels, only maxacalcitol downregulated IL-23p19 expression. Significantly increased Foxp3+ cell infiltrations and IL-10 expression were noted in maxacalcitol-treated IMQ skin. Adoptive transfer of Treg cells from maxacalcitol-treated donor mice improved IMQ-induced inflammation clinically and histopathologically more than the recipients of Treg cells from BV-treated donor groups, showing reduced levels of inflammatory cytokines and increased IL-10 expression. These results indicate that maxacalcitol reduces psoriasiform skin inflammation by inducing Treg cells as well as downregulating IL-23 and IL-17 production.

Hau CS ，Shimizu T ，Tada Y ，Kamata M ，Takeoka S ，Shibata S ，Mitsui A ，Asano Y ，Sugaya M ，Kadono T ，Sato S ，Watanabe S ... -  《-》

Apremilast downregulates interleukin-17 production and induces splenic regulatory B cells and regulatory T cells in imiquimod-induced psoriasiform dermatitis.

Apremilast, a selective inhibitor of the enzyme phosphodiesterase 4, is efficacious for psoriasis. However, detailed in vivo effects of apremilast on psoriasis remain to be elucidated. To examine the in vivo effects of apremilast on psoriasis. Psoriasiform dermatitis was induced by applying imiquimod (IMQ) on the murine shaved back skin for six days. Mice were treated with apremilast or vehicle intraperitoneally daily. Apremilast alleviated IMQ-induced psoriasiform dermatitis clinically and pathologically on days 3-6 by reducing infiltration of antigen-presenting cells and interleukin (IL)-17A-positive cells and increasing infiltration of Foxp3-postive cells into the skin on day 6, although a significant increase in IL-10 mRNA level was not observed on day 2. In addition, mRNA expression of IL-17A, IL-17F, and IL-22 was lower in the skin of IMQ-applied mice treated with apremilast than in those without apremilast on day 2, and apremilast inhibited infiltration of IL-17A-producing γδ T cells into the dermis on day 6. Furthermore, apremilast induced regulatory T cells and regulatory B cells in the spleen but not in the draining lymph nodes. Apremilast downregulated IL-17 production and induced splenic regulatory B cells and regulatory T cells in an IMQ-induced psoriasiform dermatitis mouse model.

Uchida H ，Kamata M ，Shimizu T ，Egawa S ，Ito M ，Takeshima R ，Mizukawa I ，Watanabe A ，Tada Y ... -  《-》

Fingolimod ameliorates imiquimod-induced psoriasiform dermatitis by sequestrating interleukin-17-producing ?d T cells in secondary lymph nodes.

Psoriasis is a chronic inflammatory skin disease. Interleukin (IL)-17A plays a key role in the pathogenesis of psoriasis. Fingolimod, which is available for the treatment of multiple sclerosis, exerts anti-inflammatory effects by sequestrating inflammatory lymphocytes in secondary lymphoid tissues and the thymus. The effect of fingolimod on psoriasis has not been reported yet. Our objectives were to investigate the effect of fingolimod on psoriasis utilizing mice with imiquimod (IMQ)-induced psoriasiform dermatitis, and explore the possibility of fingolimod as a therapeutic agent for psoriasis. Psoriasiform dermatitis was induced by imiquimod application on murine shaved back skin for six days. Fingolimod prepared in phosphate-buffered saline (PBS), or PBS alone as a control, was administered intraperitoneally daily from days 0 to 5. Fingolimod ameliorated IMQ-induced psoriasis dermatitis clinically and histologically. On day 6, the mRNA expression level of IL-17A was lower in the skin of fingolimod-treated mice than in that of PBS-treated mice, whereas it was higher in the inguinal lymph nodes of fingolimod-treated mice than in those of PBS-treated mice. Flow cytometric analyses revealed that fingolimod reduced IL-17A-producing ?d T cells infiltrating into the skin, whereas it increased these cells in the inguinal lymph nodes. Fingolimod inhibited egress of Langerhans cells from the skin to lymph nodes. Our results demonstrated that fingolimod showed effectiveness for IMQ-induced psoriasiform dermatitis by hindering the emigration of IL-17A-producing ?d T cells from the lymph nodes to the skin, and suggest that fingolimod is a promising candidate for the treatment of psoriasis.

Okura I ，Kamata M ，Asano Y ，Mitsui A ，Shimizu T ，Sato S ，Tada Y ... -  《-》

IBI112, a selective anti-IL23p19 monoclonal antibody, displays high efficacy in IL-23-induced psoriasiform dermatitis.

Psoriasis is a highly prevalent inflammatory skin disease. Plaque psoriasis is the most common type of psoriasis, and the interleukin (IL)-23/IL-17 axis plays a key role in disease progression. In this article, we describe IBI112, a highly potent anti-IL-23 monoclonal antibody under clinical development, which efficiently neutralizes IL23p19, a subunit of IL-23, to abrogate IL-23 binding to its receptor and block downstream signal transducer and activator of transcription 3 (STAT3) phosphorylation. Specifically, IBI112 blocked IL-23 induced downstream IL-17 production from splenocytes. In addition, IBI112 administration reduced skin thickness in a psoriasis-like epidermal hyperplasia mouse model challenged by continuous hIL-23 injection. IBI112 showed synergism with an anti-IL-1R antibody in controlling disease progression in an imiquimod (IMQ) -induced psoriasis model. Moreover, with mutations in Fc fragment of IBI112, extended half-life was observed when compared to the wild-type IgG1 version in both human-FcRn-knock-in mice and cynomolgus monkeys. IBI112 was well tolerated after high dose administration in cynomolgus monkeys. In summary, we have developed an extended half-life, anti-IL-23p19 monoclonal antibody, IBI112, which efficiently neutralized IL-23, blocked IL-23-induced IL-17 production, and alleviated disease symptoms in two mouse models of psoriasis.

Li L ，Wu Z ，Wu M ，Qiu X ，Wu Y ，Kuang Z ，Wang L ，Sun T ，Liu Y ，Yi S ，Jing H ，Zhou S ，Chen B ，Wu D ，Wu W ，Liu J ... -  《-》