Staphylococcus aureus skin colonization promotes SLE-like autoimmune inflammation via neutrophil activation and the IL-23/IL-17 axis.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by inflammation of various organs such as skin, kidneys, bones, and brain and the presence of autoantibodies. Although the cause of SLE is not completely understood, environmental factors, genetic susceptibility, hormone factors, and environmental factors are thought to play essential roles in the pathogenesis of SLE. Among environmental factors, the microbiota are linked to the development of different autoimmune diseases. The microbiota in the nasal cavity and gut are involved in SLE development, but the influence of skin microbiota is still unclear. Here, we demonstrated that epithelial cell-specific IκBζ-deficient (NfkbizΔK5) mice showed spontaneous skin inflammation with increased abundance of Staphylococcus aureus on the skin. When S. aureus was epicutaneously applied on NfkbizΔK5 mice, NfkbizΔK5 mice developed SLE-associated autoantibodies, anti-dsDNA antibodies, anti-Sm antibodies, and glomerulonephritis with IgG deposition. Epicutaneous S. aureus application significantly increased staphylococcal colonization on the skin of NfkbizΔK5 mice with reduced expression of several antimicrobial peptides in the skin. This staphylococcal skin colonization promoted caspase-mediated keratinocyte apoptosis and neutrophil activation, inducing the interleukin-23 (IL-23)/IL-17 immune response by activating dendritic cells and T cells. Furthermore, the subcutaneous administration of anti-IL-23p19 and anti-IL-17A antibodies alleviated the systemic autoimmune response. Together, these findings underscore epithelial-immune cross-talk disturbances caused by skin dysbiosis as an essential mediator inducing autoimmune diseases.

Sarcoidosis-Lymphoma Syndrome Associated with Folliculotropic Peripheral T Cell Lymphoma Not Otherwise Specified.

Sarcoidosis is occasionally accompanied by hematologic malignancies, including cutaneous T-cell lymphoma, called sarcoidosis-lymphoma syndrome. Although the mechanism underlying the induction of lymphomas is still unknown, understanding the immunological background of sarcoidosis could help explain the possible mechanisms of the induction of lymphomas. In this report, we describe a case of sarcoidosis-lymphoma syndrome associated with folliculotropic peripheral T cell lymphoma not otherwise specified, which caused dense infiltration of CD30+ CD163+ tumor-associated macrophages (TAMs) only in the lesional skin. Our present case might suggest the significance of TAMs in developing sarcoid-lymphoma syndrome.

A randomized double-blind trial of intravenous immunoglobulin for bullous pemphigoid.

BACKGROUND: Patients with steroid-resistant bullous pemphigoid (BP) require an appropriate treatment option. OBJECTIVE: A multicenter, randomized, placebo-controlled, double-blind trial was conducted to investigate the therapeutic effect of high-dose intravenous immunoglobulin (IVIG; 400mg/kg/day for 5days) in BP patients who showed no symptomatic improvement with prednisolone (≥0.4mg/kg/day) administered. METHODS: We evaluated the efficacy using the disease activity score on day15 (DAS15) as a primary endpoint, and changes in the DAS over time, the anti-BP180 antibody titer, and safety for a period of 57days as secondary endpoints. RESULTS: We enrolled 56 patients in this study. The DAS15 was 12.5 points lower in the IVIG group than in the placebo group (p=0.089). The mean DAS of the IVIG group was constantly lower than that of the placebo group throughout the course of observation, and a post hoc analysis of covariance revealed a significant difference (p=0.041). Furthermore, when analyzed only in severe cases (DAS≥40), the DAS15 differed significantly (p=0.046). The anti-BP180 antibody titers showed no difference between the two groups. CONCLUSION: IVIG provides a beneficial therapeutic outcome for patients with BP who are resistant to steroid therapy.

Periostin in the Cancer Stroma of Mycosis Fungoides Palmaris et Plantaris: A Case Report and Immunohistochemical Study.

Mycosis fungoides palmaris et plantaris (MFPP) is a rare variant of mycosis fungoides limited to the palms and soles. Although little is known about the pathogenesis of MFPP, this variant of mycosis fungoides presents a relatively good prognosis. In this report, we describe an 85-year-old Japanese man with MFPP. Immunohistochemical staining revealed the dense deposition of periostin in the cancer stroma, as well as infiltration of CD163(+)CD206(-) tumor-associated macrophages (TAMs), which suggested the phenotypes of TAMs were not polarized to the M2 phenotype in the lesional skin of MFPP. Our present case might suggest one of the possible reasons for the good prognosis of MFPP.

Comparison of interleukin-17- producing cells in different clinical types of alopecia areata.

T helper 17 cells, characterized by interleukin-17 (IL-17) production, play a critical role in the pathogenesis of autoimmune disease, including alopecia areata (AA). In this report, we employed immunohistochemical staining for IL-17-producing cells, as well as interferon-γ-producing cells, granulysin-bearing cells and Foxp3+ regulatory T cells, and performed a quantitative analysis of IL-17-producing cells in the lesional skin of several clinical forms of AA by TissueFAXS analysis. Among them, interestingly, the ratio of IL-17-producing cells in acute, diffuse and total alopecia was significantly lower than those of multiple types of AA. Our study sheds light on one of the possible immunological mechanisms of AA.

Successful treatment of syringotropic CD8+ mycosis fungoides accompanied by hypohidrosis with vorinostat and retinoids.

We describe a 34-year-old Japanese man with syringotropic CD8+ mycosis fungoides (MF) accompanied by hypohidrosis who was treated with vorinostat and retinoids. Interestingly, immunohistochemical staining for dermcidin revealed a decrease of sweat in the eccrine glands, and a sweat test by the iodine starch method proved hypohidrosis in the MF-affected areas. Six months after treatment with this combination therapy, the patient's advanced MF was under control.

Dermal melanocytosis of the helix.

A 2-year-old Japanese boy had a congenital gray-blue macule involving the right helix along with a few melanotic spots on both sclerae. Histopathology showed dermal melanocytosis. Q-switched alexandrite laser treatment induced a good cosmetic response. This patient shows the overlap between Ota and Ito nevi, and we suggest dermal melanocytosis is better used as a generic term for these unusual pigmentations.

Oxidation of cell surface thiol groups by contact sensitizers triggers the maturation of dendritic cells.

p38 mitogen-activated protein kinase (MAPK) has a crucial role in the maturation of dendritic cells (DCs) by sensitizers. Recently, it has been reported that the oxidation of cell surface thiols by an exogenous impermeant thiol oxidizer can phosphorylate p38 MAPK. In this study, we examined whether sensitizers oxidize cell surface thiols of monocyte-derived DCs (MoDCs). When cell surface thiols were quantified by flow cytometry using Alexa fluor maleimide, all the sensitizers that we examined decreased cell surface thiols on MoDCs. To examine the effects of decreased cell surface thiols by sensitizers on DC maturation, we analyzed the effects of an impermeant thiol oxidizer, o-phenanthroline copper complex (CuPhen). The treatment of MoDCs with CuPhen decreased cell surface thiols, phosphorylated p38 MAPK, and induced MoDC maturation, that is, the augmentation of CD83, CD86, HLA-DR, and IL-8 mRNA, as well as the downregulation of aquaporin-3 mRNA. The augmentation of CD86 was significantly suppressed when MoDCs were pretreated with N-acetyl-L-cystein or treated with SB203580. Finally, we showed that epicutaneous application of 2,4-dinitrochlorobenzene on mouse skin significantly decreased cell surface thiols of Langerhans cells in vivo. These data suggest that the oxidation of cell surface thiols has some role in triggering DC maturation by sensitizers.