Increased expression of heat shock protein 90 in keratinocytes and mast cells in patients with psoriasis.

BACKGROUND: Psoriasis is a chronic inflammatory skin disease and various stress factors mediate inflammation. Heat shock protein (HSP) 90 plays an important role in cell survival; cytokine signaling, such as interleukin-17 receptor signaling; and immune responses. OBJECTIVE: We sought to elucidate protein expression and distribution of HSP90 in psoriasis. METHODS: HSP90 expression and its cellular source were analyzed on normal-appearing, nonlesional, lesional, and ustekinumab-treated psoriatic skin using immunohistochemistry and double immunofluorescence. RESULTS: HSP90α, the inducible isoform of HSP90, was significantly up-regulated in epidermal keratinocytes and mast cells of lesional skin and down-regulated after ustekinumab therapy. LIMITATIONS: There was a limited sample size. CONCLUSIONS: HSP90 from keratinocytes and mast cells is a key regulator of psoriatic inflammation and HSP90 inhibitors may represent a novel therapeutic approach to the disease.

Cytokines and chemokines in irritant contact dermatitis.

Irritant contact dermatitis is a result of activated innate immune response to various external stimuli and consists of complex interplay which involves skin barrier disruption, cellular changes, and release of proinflammatory mediators. In this review, we will focus on key cytokines and chemokines involved in the pathogenesis of irritant contact dermatitis and also contrast the differences between allergic contact dermatitis and irritant contact dermatitis.

Propionibacterium acnes vaccination induces regulatory T cells and Th1 immune responses and improves mouse atopic dermatitis.

Atopic dermatitis (AD) is a chronic disease characterized by a polarized Th2 immune response. Propionibacterium acnes (P. acnes) has been shown to elicit strong Th1 immune responses. We hypothesized that the host immune response to P. acnes will prevent the development of AD. To demonstrate this hypothesis, we investigated the effect of P. acnes vaccination on AD that occurs in keratin 14/driven caspase-1 transgenic mouse. Vaccination with low dose of P. acnes successfully prevented clinical manifestations in the skin of AD mice associated with systemic and cutaneous increased expression of Th1-type cytokines but without suppression of Th2 cytokines. Interestingly, the numbers of IFN-γ(+) T cells, FoxP3(+) CD4(+) CD25(+) T cells (nTreg) and IL-10(+) T cells (Tr1) were significantly increased in the spleen. P. acnes vaccination has effects to alter the cytokine milieu and may be useful for the improvement of atopic symptom.

SLIT improves cedar pollinosis by restoring IL-10 production from Tr1 and Monocytes∼IL-10 productivity is critical for becoming allergic∼.

BACKGROUND: Allergen-specific immunotherapy (SIT) is currently used for several allergic disorders and IL-10-producing regulatory T cells (Tr1) induced by SIT suppress allergic reactions. We investigated the relation between IL-10 production and acquiring allergy. METHODS: A prospective study was undertaken to evaluate the effect of SIT on IL-10 production in T cells and other cell fractions in children with pollinosis. In addition, blood samples were collected from non-allergic healthy controls and patients with pollinosis to compare the levels of IL-10 production. PBMC were cultured with pollen peptides or control allergens, and the IL-10 production from monocyte and CD4 T cell was analyzed. RESULTS: Monocytes and CD4 T cells from SIT group of patients produced high levels of IL-10, suggesting that the induction of IL-10 is essential for inducing T cell tolerance. IL-10 production from monocytes and T cells was significantly increased in non-allergic controls compared to patients with pollinosis. This high IL-10 production was observed even when PBMC were stimulated with antigens other than pollen peptides. CONCLUSIONS: IL-10 is critical for induction of specific T cell tolerance, and increased production of IL-10 by monocytes and T cells during inflammatory responses or after SIT may influence effector cells in allergy. Present data implicates that the low productivity of IL-10 by monocytes and T cells is closely related with sensitivity to multiple allergens, and resistance to allergic diseases. Augmentation of constitutive IL-10 production from immune system is a potential therapeutic approach for allergic disorders.

Vitamins A and D are potent inhibitors of cutaneous lymphocyte-associated antigen expression.

BACKGROUND: Cutaneous lymphocyte-associated antigen (CLA) is a surface glycoprotein expressed by skin-homing T cells. This carbohydrate moiety expressed on mucin-like surface glycoproteins, including P-selectin glycoprotein ligand 1 and CD43, confers binding activity to dermal endothelial E-selectin and is critical for T-cell recruitment to the skin. Vitamin A (retinoic acid [RA]) and the active form of vitamin D3 (1,25 dihydroxyvitamin D3 [1,25D(3)]) have been used to treat certain T cell-mediated inflammatory skin diseases, as well as cutaneous T-cell lymphomas; however, their effect on CLA expression has not been studied. OBJECTIVE: We analyzed the effects of RA and 1,25D(3) on expression of CLA and other lymphocyte-homing receptors on human T cells. METHODS: We cultured human T cells with 1,25D(3) and RA and analyzed the expression of CLA and other homing receptors. We also pretreated mice with either vitamin and then induced an antigen-dependent contact hypersensitivity response. RESULTS: Both RA and 1,25D(3) downregulated expression of the CLA and, in parallel, functional E-selectin ligand. Whereas RA increased expression of the gut-homing receptor alpha4beta7 and reduced L-selectin expression, 1,25D(3) had no effect on other homing receptors. In an in vivo assay treatment with RA or 1,25D(3) downregulated the skin infiltration of effector CD4+ T cells. CONCLUSION: These findings suggest that 1,25D(3) can selectively downregulate CLA expression without influencing lymphocyte migration patterns to other tissues.

Elevated plasma D-dimer levels in dermatomyositis patients with cutaneous manifestations.

To explore the influence of dermatomyositis (DM)-specific cutaneous manifestations (scm) on systemic coagulation and fibrinolysis, we retrospectively studied plasma D-dimer levels with/without venous thromboembolism (VTE), malignancy, infection or other connective tissue diseases (CTDs) and scm. One hundred fifty patients with DM were retrospectively investigated using medical records regarding scm, VTE, malignancy, infection, other CTDs, laboratory data and systemic corticosteroid therapy. All DM patients were categorized as follows: group 1, without scm, VTE, infection, malignancy or other accompanying CTDs; group 2, with scm only; and group 3, with VTE, infection, malignancy and other accompanying CTDs but without scm. The D-dimer plasma levels were significantly increased in group 3 compared with healthy subjects and those in groups 1 and 2 (p < 0.001). The D-dimer plasma level in group 2 was significantly increased compared with healthy subjects and those in group 1 (p < 0.001). Increased D-dimer plasma levels were detected in DM patients with scm without detectable VTE, malignancy, infection or accompanying CTDs. In addition to the known risk factors for increased plasma D-dimer levels in DM patients, including VTE, malignancy, infection and other accompanying autoimmune diseases, the presence of cutaneous manifestations should be considered as a new clinical risk factor.

The Plasma Levels of ADAMTS-13, von Willebrand Factor, VWFpp, and Fibrin-Related Markers in Patients With Systemic Sclerosis Having Thrombosis.

This study aimed to examine the hemostatic abnormalities in patients with systemic sclerosis (SSc) and the relationship between these abnormalities and thrombotic events (THEs), focusing on the difference in diffuse cutaneous SSc (dcSSc) and limited cutaneous SSc (lcSSc). The plasma levels of ADAMTS-13 (a disintegrin-like and metalloproteinase with thrombospondin type 1 motifs 13), von Willebrand factor (VWF), VWF propeptide (VWFpp), d-dimer, and soluble fibrin (SF) were measured in 233 patients with SSc. The relationship between their levels and organ involvement, including THEs and interstitial lung disease (ILD), was evaluated. The plasma levels of VWF and VWFpp were significantly elevated and ADAMTS-13 activity was significantly decreased in patients with SSc compared to healthy participants. The VWFpp in dcSSc was significantly higher than in lcSSc. Twelve patients with SSc were complicated with acute THE, and 25 patients with SSc were complicated with past THE. The plasma levels of d-dimer and SF were significantly elevated in patients with SSc having THE. The plasma levels of VWF and VWFpp were significantly elevated in patients with SSc having ILD. The plasma levels of d-dimer were elevated in patients with SSc having other connective tissue diseases (CTDs). The plasma levels of ADAMTS-13 were significantly decreased and VWF, VWFpp, and SF were increased in patients with a d-dimer level of ≥1 µg/mL. Systemic sclerosis carries a high risk of THE, especially in patients with other CTDs. Plasma hemostasis-related markers are closely related to ILD and THE. These markers are important as markers of organ involvement as well as THE.

Successful combination therapy of propranolol and prednisolone for a case with congenital Kasabach-Merritt syndrome.

A male fetus was delivered by cesarean section with a large hemangioma on his right chest and thrombocytopenia. Clinically, Kasabach-Merritt syndrome (KMS) was suspected, and immediately he was treated with daily prednisolone (PSL) 1 mg/kg and recombinant thrombomodulin without response. Additional propranolol (1-3 mg/kg per day) and increased PSL 2 mg/kg per day therapy successfully controlled his disseminated intravascular coagulation and decreased the tumor size without serious side-effects. No relapse of KMS was observed after cease of PSL and propranolol. Combined use of propranolol and corticosteroid is expected as a candidate therapeutic tool for KMS.

A case of histopathologically typical toxic epidermal necrolysis despite no visible blisters or erosive lesions.

Toxic epidermal necrolysis (TEN) is a rare life-threatening disease characterized by blister formation and erosion over the entire body surface resulting from extensive keratinocyte death. We reported a case of TEN that developed in a 68-year-old man with hepatitis C virus liver cirrhosis three weeks after treatment with allopurinol. Exanthema developed as multiple target-like lesions, and erythroderma within five days without forming visible erosive lesions or obvious mucous membrane involvement. Reactivation of human herpes virus-6 or other herpes virus was not detected by polymerase chain reaction or serologic studies, and drug-induced hypersensitivity syndrome was ruled out. The finding of panepidermal necrosis on histopathological examination led to a diagnosis of TEN. Exanthema, fever and renal dysfunction responded to oral prednisolone, but the patient died of liver failure. Cases of TEN with histopathologically proven panepidermal necrosis without apparent blisters or erosions have rarely been reported because they do not fulfill the previously proposed diagnostic criteria for TEN. This finding, the discrepancy between the clinical and the histopathological manifestations, should not be overlooked in a case suspicious of TEN, and the importance of the histopathological examination should be emphasized in the differential diagnosis of TEN.

Persistent release of IL-1s from skin is associated with systemic cardio-vascular disease, emaciation and systemic amyloidosis: the potential of anti-IL-1 therapy for systemic inflammatory diseases.

The skin is an immune organ that contains innate and acquired immune systems and thus is able to respond to exogenous stimuli producing large amount of proinflammatory cytokines including IL-1 and IL-1 family members. The role of the epidermal IL-1 is not limited to initiation of local inflammatory responses, but also to induction of systemic inflammation. However, association of persistent release of IL-1 family members from severe skin inflammatory diseases such as psoriasis, epidermolysis bullosa, atopic dermatitis, blistering diseases and desmoglein-1 deficiency syndrome with diseases in systemic organs have not been so far assessed. Here, we showed the occurrence of severe systemic cardiovascular diseases and metabolic abnormalities including aberrant vascular wall remodeling with aortic stenosis, cardiomegaly, impaired limb and tail circulation, fatty tissue loss and systemic amyloid deposition in multiple organs with liver and kidney dysfunction in mouse models with severe dermatitis caused by persistent release of IL-1s from the skin. These morbid conditions were ameliorated by simultaneous administration of anti-IL-1α and IL-1ß antibodies. These findings may explain the morbid association of arteriosclerosis, heart involvement, amyloidosis and cachexia in severe systemic skin diseases and systemic autoinflammatory diseases, and support the value of anti-IL-1 therapy for systemic inflammatory diseases.

Mutant interleukin-4/13 signaling blockade successfully suppresses acute phase inflammation.

Atopic dermatitis (AD) is a chronic disease with Th2-type-cytokine dominant profile. Several cytokines and related peptides had been tried for the treatment of AD but with unsuccessful results; a part of the reason is the limitation of their biological half time. We have recently developed a highly efficient mouse dominant negative IL-4/IL-13 DNA vaccine, which blocks both IL-4 and IL-13 signal transductions, resulting in the amelioration of atopic reaction. At the next step, the further consistent protein supplementation system is required for stable suppression of allergic reaction. To examine the effects of mutant IL-4/13 protein supplementation from skin, a keratinocyte-specific dominant negative IL-4-transgenic mouse line (IL-4DM) was established. The anti-inflammatory function was evaluated measuring ear thickness and analyzing histological change in mice AD model induced by repeated elicitation of oxazolone. In IL-4DM, ear thickness was suppressed significantly in the early phase of the elicitation schedule of contact hypersensitivity response. We next transplanted IL-4DM skin to normal control mice, and investigated effects in inflammatory reactions. In IL-4DM-skin-grafted mice, the inflammatory response was suppressed significantly similarly in the early phase accompanied with lesional suppressed Th2-type-cytokine signaling transduction. IL-4DM skin has the anti-inflammatory function especially in the acute phase of AD. Although there are several issues to be addressed for human application, the present results implicated that the gene manipulated skin transplantation is a potent therapeutic strategy to control allergic reactions.

Intranasally administered antigen 85B gene vaccine in non-replicating human Parainfluenza type 2 virus vector ameliorates mouse atopic dermatitis.

Atopic dermatitis (AD) is a refractory and recurrent inflammatory skin disease. Various factors including heredity, environmental agent, innate and acquired immunity, and skin barrier function participate in the pathogenesis of AD. T -helper (Th) 2-dominant immunological milieu has been suggested in the acute phase of AD. Antigen 85B (Ag85B) is a 30-kDa secretory protein well conserved in Mycobacterium species. Ag85B has strong Th1-type cytokine inducing activity, and is expected to ameliorate Th2 condition in allergic disease. To perform Ag85B function in vivo, effective and less invasive vaccination method is required. Recently, we have established a novel functional virus vector; recombinant human parainfluenza type 2 virus vector (rhPIV2): highly expressive, replication-deficient, and very low-pathogenic vector. In this study, we investigated the efficacy of rhPIV2 engineered to express Ag85B (rhPIV2/Ag85B) in a mouse AD model induced by repeated oxazolone (OX) challenge. Ear swelling, dermal cell infiltrations and serum IgE level were significantly suppressed in the rhPIV2/Ag85B treated mouse group accompanied with elevated IFN-γ and IL-10 mRNA expressions, and suppressed IL-4, TNF-α and MIP-2 mRNA expressions. The treated mice showed no clinical symptom of croup or systemic adverse reactions. The respiratory tract epithelium captured rhPIV2 effectively without remarkable cytotoxic effects. These results suggested that rhPIV2/Ag85B might be a potent therapeutic tool to control allergic disorders.

Calcineurin inhibitors suppress cytokine production from memory T cells and differentiation of naïve T cells into cytokine-producing mature T cells.

T cells have been classified as belonging to the Th1 or Th2 subsets according to the production of defining cytokines such as IFN-γ and IL-4. The discovery of the Th17 lineage and regulatory T cells shifted the simple concept of the Th1/Th2 balance into a 4-way mechanistic pathway of local and systemic immunological activity. Clinically, the blockage of cytokine signals or non-specific suppression of cytokine predominance by immunosuppressants is the first-line treatment for inflammatory T cell-mediated disorders. Cyclosporine A (CsA) and Tacrolimus (Tac) are commonly used immunosuppressants for the treatment of autoimmune disease, psoriasis, and atopic disorders. Many studies have shown that these compounds suppress the activation of the calcium-dependent phosphatase calcineurin, thereby inhibiting T-cell activation. Although CsA and Tac are frequently utilized, their pharmacological mechanisms have not yet been fully elucidated.In the present study, we focused on the effects of CsA and Tac on cytokine secretion from purified human memory CD4(+)T cells and the differentiation of naïve T cells into cytokine-producing memory T cells. CsA or Tac significantly inhibited IFN-γ, IL-4, and IL-17 production from memory T cells. These compounds also inhibited T cell differentiation into the Th1, Th2, and Th17 subsets, even when used at a low concentration. This study provided critical information regarding the clinical efficacies of CsA and Tac as immunosuppressants.

Intratumoral injection of Propionibacterium acnes suppresses malignant melanoma by enhancing Th1 immune responses.

Malignant melanoma (MM) is an aggressive cutaneous malignancy associated with poor prognosis; many putatively therapeutic agents have been administered, but with mostly unsuccessful results. Propionibacterium acnes (P. acnes) is an aerotolerant anaerobic gram-positive bacteria that causes acne and inflammation. After being engulfed and processed by phagocytes, P. acnes induces a strong Th1-type cytokine immune response by producing cytokines such as IL-12, IFN-γ and TNF-α. The characteristic Th2-mediated allergic response can be counteracted by Th1 cytokines induced by P. acnes injection. This inflammatory response induced by P. acnes has been suggested to have antitumor activity, but its effect on MM has not been fully evaluated.We analyzed the anti-tumor activity of P. acnes vaccination in a mouse model of MM. Intratumoral administration of P. acnes successfully protected the host against melanoma progression in vivo by inducing both cutaneous and systemic Th1 type cytokine expression, including TNF-α and IFN-γ, which are associated with subcutaneous granuloma formation. P. acnes-treated tumor lesions were infiltrated with TNF-α and IFN-γ positive T cells. In the spleen, TNF-α as well as IFN-γ producing CD8(+)T cells were increased, and interestingly, the number of monocytes was also increased following P. acnes administration. These observations suggest that P. acnes vaccination induces both systemic and local antitumor responses. In conclusion, this study shows that P. acnes vaccination may be a potent therapeutic alternative in MM.

Granzyme B is a novel interleukin-18 converting enzyme.

BACKGROUND: Granzyme B (GrB) is recognized to induce apoptosis; however, little is known about its possible role in other biological events. IL-18, a potent inflammatory cytokine, is produced as an inactive precursor (proIL-18). Several cells, including monocytes/macrophage lineage and non-hematopoietic cells such as keratinocytes, produce proIL-18. ProIL-18 requires appropriate processing to become active. Caspase-1 is the authentic IL-18 processing enzyme and is essential for IL-18 release from monocyte/macrophage lineage cells. However, caspase-1 is absent in non-hematopoietic cells, suggesting that there is another candidate to cleave proIL-18 except for caspase-1. OBJECTIVE: GrB can invade and be active in cytoplasm of non-hematopoietic cells via perforin, therefore we investigated whether GrB converts proIL-18 into the biologically active form. METHODS: Recombinant proIL-18 (rproIL-18) was produced and purified for protease reaction with GrB; this incubate was evaluated by immunoblotting. Biological activity of the proteolytic fragment cleaved by GrB was determined by IFN-gamma assay using KG-1 cells. IFN-gamma induction was also analyzed between extracts from GrB(+)/caspase-1(-) human CD8+ T cells and proIL-18 from normal human keratinocytes (NHK). RESULTS: The proteolytic fragment that GrB cleaved proIL-18 had the same sequence and biological activity compared with mature IL-18 cleaved by caspase-1. Culture extracts from CD8+ T cells was able to cleave proIL-18 into authentic mature IL-18. IFN-gamma induction was also detected in NHK treated with CD8+ T cells. CONCLUSION: GrB is a potent IL-18 converting enzyme and suggest that GrB secreted by CTLs and/or NK cells may initiate IL-18 release from target cells, leading to the development of inflammation.