Elicitation of Delayed Type Hypersensitivity in Chicks after In Ovo Sensitization with Different Molecular Forms of the Same Hapten

Lymphocyte sensitization, which participates in delayed type hypersensitivity (DTH) in chick embryos, was studied. The in ovo injection of dinitrophenylated keyhole limpet hemocyanine (DNP-KLH) or DNP-dextran (DNP-D) led to delayed onset of the hapten-specific reaction as shown by allergic contact dermatitis (ACD) after hatching. The extent of the ACD response was not directly dependent on the antigen dosage or the number of injections given for sensitizing. The magnitude of the ACD response was higher in chicks sensitized with DNP-D than in those given DNP-KLH. These findings suggest the presence of embryonic lymphocytes which can be sensitized by in ovo antigenic stimulation at the later stage of embryogenesis and may make possible the differentiation of functional lymphocytes. Antigen stimulation with higher doses may be inadequate for the in ovo sensitization of embryonic lymphocytes. The ACD response elicited by DNFB in chicks primed with either DNP-KLH or DNP-D was thought to be T-cell dependent, from the kinetics of the ACD peak within a period of 24 to 48 hr. Furthermore the conditions for in ovo sensitization of embryonic lymphocytes by DNP-D seem to be different from those for sensitization by DNP-KLH.     

An increased proportion of circulating Th22 and Tc22 cells in psoriasis

Psoriasis is a common dermatosis mediated by T cells. This study investigated the correlation of Th22 cells and Tc22 cells with psoriasis. A total of 30 psoriasis patients and 11 age- and sex-matched healthy controls were recruited for this study. The proportions of circulating Th22 and Tc22 cells, expression of aryl hydrocarbon receptor, and IL-22 levels in the psoriasis patients were significantly higher than those in the control subjects (p < 0.05). There was a positive correlation between the proportion of circulating Th22 cells, IL-22 levels, and PASI score. The IL-22 levels and PASI score were also positively correlated. There was no correlation between the proportion of circulating Tc22 cells and IL-22 level or PASI score. These data are consistent with Th22 cells involvement in the pathogenesis of psoriasis.     

Silkworm dropping extract ameliorate trimellitic anhydride-induced allergic contact dermatitis by regulating Th1/Th2 immune response

Allergic contact dermatitis (ACD) is an inflammatory skin disease caused by hapten-specific immune response. Silkworm droppings are known to exert beneficial effects during the treatment of inflammatory diseases. Here, we studied whether topical treatment and oral administration of silkworm dropping extract (SDE) ameliorate trimellitic anhydride (TMA)-induced ACD. In ACD mice model, SDE treatment significantly suppressed the increase in both ear thickness and serum IgE levels. Furthermore, IL-1β and TNF-α levels were reduced by SDE. In allergic responses, SDE treatment significantly attenuated the production of the Th2-associated cytokine IL-4 in both ear tissue and draining lymph nodes. However, it increased the production of the Th1-mediated cytokine IL-12. Thus, these results showed that SDE attenuated TMA-induced ACD symptoms through regulation of Th1/Th2 immune response. Taken together, we suggest that SDE treatment might be a potential agent in the prevention or therapy of Th2-mediated inflammatory skin diseases such as ACD and atopic dermatitis.

Abbreviations: ACD: allergic contact dermatitis; AD: atopic dermatitis; APC: antigen presenting cells; CCL: chemokine (C-C motif) ligand; CCR: C-C chemokine receptor; Dex: dexamethasone; ELISA: enzyme-linked immunosorbent assay; IFN: interferon; Ig: immunoglobulin; IL: interleukin; OVA: ovalbumin; PS: prednisolone; SDE: silkworm dropping extract; Th: T helper; TMA: trimellitic anhydride; TNF: tumor necrosis factor     

Psoriasis and hypertension severity: results from a case-control study

Background

Epidemiologic studies have provided new insights into the association between psoriasis and cardiovascular diseases. Previous population studies have examined hypertension frequency in psoriasis patients. However, the relationship between severity of hypertension and psoriasis has not been characterized.

Objective

We sought to investigate whether patients with psoriasis have more difficult-to-manage hypertension compared to non-psoriatic hypertensive patients.

Approach

We performed a case-control study using the University of California Davis electronic medical records. The cases were defined as patients diagnosed with both psoriasis and hypertension, and controls were defined as patients with hypertension and without psoriasis. In this identified population, 835 cases were matched on age, sex, and body mass index (BMI) to 2418 control patients.

Key Results

Treatment with multiple anti-hypertensives was significantly associated with the presence of psoriasis using univariate (p<0.0001) and multivariable analysis, after adjusting for diabetes, hyperlipidemia, and race (p<0.0001). Compared to hypertensive patients without psoriasis, psoriasis patients with hypertension were 5 times more likely to be on a monotherapy antihypertensive regimen (95% CI 3.607.05), 9.5 times more likely to be on dual antihypertensive therapy (95% CI 6.68–13.65), 16.5 times more likely to be on triple antihypertensive regimen (95% CI 11.01–24.84), and 19.9 times more likely to be on quadruple therapy or centrally-acting agent (95% CI 10.58–37.33) in multivariable analysis after adjusting for traditional cardiac risk factors.

Conclusions

Psoriasis patients appear to have more difficult-to-control hypertension compared to non-psoriatic, hypertensive patients.     

Disparate cytotoxic activity of nickel-specific CD8+ and CD4+ T cell subsets against keratinocytes

Allergic contact dermatitis (ACD) is the result of an exaggerated immune reaction to haptens mediated by skin-homing T cells, but the effector mechanisms responsible for the tissue damage are poorly understood. Here we studied the capacity of distinct subsets of hapten-specific T cells to induce apoptosis in autologous keratinocytes. Skin- and blood-derived nickel-specific CD8+ T cytotoxic 1 (Tc1) and Tc2 clones as well as CD4+ Th1 and Th2 expressed the cutaneous lymphocyte-associated Ag and exhibited strong MHC-restricted cytotoxicity against nickel-coupled B lymphoblasts, as detected by the [3H]TdR release assay. Both Tc1 and Tc2 clones, but not CD4+ T cells, displayed a significant cytotoxic activity against resting nickel-modified keratinocytes. Following IFN-gamma treatment, keratinocytes expressed MHC class II and ICAM-1 and became susceptible to Th1-mediated, but not Th2-mediated, cytotoxicity. The molecules of the two major cytotoxic pathways, Fas ligand (FasL) and perforin, were expressed by Tc1, Tc2, and Th1 cells, whereas Th2 cells expressed only FasL. Experiments performed in the presence of specific inhibitors of the perforin (concanamycin A) and FasL (brefeldin A) pathway indicated that perforin-mediated killing dominated in Tc1 and Tc2, and FasL-mediated cytotoxicity prevailed in Th2 clones, with a more heterogeneous behavior in the case of Th1 cells. Finally, perforin mRNA was expressed in ACD lesional skin, as assessed by RT-PCR analysis. In aggregate, our results indicate that keratinocytes can be target of multiple hapten-specific CTL responses, that may have distinct roles in the epidermal injury during ACD.     

T cell-regulated neutrophilic inflammation in autoinflammatory diseases

Previous studies of acute generalized exanthematous pustulosis, a peculiar drug hypersensitivity reaction, suggested that CXCL8-producing T cells regulate sterile, polymorphonuclear neutrophil-rich skin inflammations. In this study, we test the hypothesis of whether CXCL8-producing T cells are present in autoinflammatory diseases like pustular psoriasis and Beh?et's disease. Immunohistochemistry of normal skin revealed few CD4+ and CD8+ T cells, few CXCL8+ cells, and no neutrophilic infiltration, whereas in acute exacerbations of atopic dermatitis, numerous CD4+ T cells but few CD8+ T cells, neutrophils, or CXCL8+ cells were detected. In contrast, a pronounced infiltration of neutrophils and of predominantly CD4+ T cells was observed in skin biopsies from pustular psoriasis, Beh?et's disease, and acute generalized exanthematous pustulosis, with infiltrating T cells strongly positive for CXCL8 and the chemokine receptor CCR6. Skin-derived T cell clones from pustular skin reactions were positive for CCR6 but negative for CCR8 and secreted high amounts of CXCL8 and GM-CSF, often together with IFN-gamma and TNF-alpha after in vitro stimulation. Moreover, some skin-derived T cell clones from Beh?et's disease and from pustular psoriasis predominantly produced CXCL8 and GM-CSF, but failed to secrete IL-5 and IFN-gamma. These cells might represent a particular subset as they differ from both Th1 as well as Th2 T cells and are associated with a unique, neutrophil-rich sterile inflammation. Our findings suggest that CXCL8/GM-CSF-producing T cells may orchestrate neutrophil-rich pathologies of chronic autoinflammatory diseases like pustular psoriasis and Beh?et's disease.     

Th17/Treg 细胞在银屑病的发病机制研究进展

Th17细胞和Treg细胞是CD4+T细胞在不同细胞因子环境中分化出的新亚群,发挥不同的生物学效应,使机体的免疫系统处于平衡状态.Th17/Treg细胞失衡可引起一系列自身免疫性疾病.银屑病是与遗传、免疫异常有关的皮肤炎症性疾病,其发病机制尚不清楚.越来越多的研究发现,Th17细胞增多和Treg细胞减少及其分泌的细胞因子在银屑病的发病中有着重要作用.本文围绕这一机制综述了近年来有关Th17细胞、Treg细胞在银屑病发病机制中作用的研究,帮助我们更深入地了解银屑病的发病机制并为今后临床诊断和治疗提供依据.     

Low DNA repair is a risk factor in skin carcinogenesis: a study of basal cell carcinoma in psoriasis patients

We have studied DNA repair in patients with psoriasis aiming at investigating the importance of repair in chemically induced cancer. An increased risk of non-melanoma skin cancer has been observed in psoriasis patients extensively treated with tar, methotrexate and photochemotherapy (psoralen + UVA). We measured the DNA repair capacity (DRC) by a host cell reactivation (HCR) assay in lymphocytes from psoriasis patients with and without basal cell cancer and non-psoriatic persons with and without basal cell cancer (4 x 20 study persons). Among psoriasis patients we observed a significant lower DRC in patients with skin cancer compared to patients without skin cancer (P = 0.015; Mann-Whitney, one-sided). Using the median of the healthy control group (group 4) as a cutoff value to divide the psoriasis patients into groups of high and low repair, we found that individuals who had a low repair capacity had a 6.4-fold increased skin cancer risk compared to individuals with high repair (95% confidence interval (CI), 1.44-28.5). The level of DNA repair was correlated with the age at which the psoriasis patients got their first skin cancer. The lower the level of DNA repair, the earlier the psoriasis patients had their first skin tumor (P = 0.070 Spearman; one-sided). Psoriasis patients without BCC had marginally higher repair than healthy controls (P = 0.11, Mann-Whitney, two-sided). We found no difference between BCC patients without psoriasis and healthy controls. In conclusion, these findings suggest a protective role of DNA repair in a predominantly chemically induced cancer.     

Cytokine network in psoriasis revisited

Psoriasis is a chronic genetically determined, erythemato-squamous disease associated with many comorbidities. Evidence from clinical studies and experimental models support the concept that psoriasis is a T?cell-mediated inflammatory skin disease and T?helper (Th) cells -?Th1, Th17 and Th22?- play an important role in the pathogenesis. Th1 cytokines IFNγ, IL-2, as well as Th17 cytokines IL-17A, IL-17F, IL-22, IL-26, and TNFα (Th1 and Th17 cytokine) are increased in serum and lesional skin. IL-22 produced by Th17 and new subset of T helper cells, Th22, is also increased within psoriatic lesions and in the serum. Other recently recognized cytokines of significant importance in psoriasis are IL-23, IL-20 and IL-15. The IL-23/Th17 pathway plays a dominant role in psoriasis pathogenesis. Currently due to enormous methodological progress, more and more clinical and histopathological psoriatic features could be explained by particular cytokine imbalance, which still is one of the most fascinating dermatological research fields stimulating new and new generations of researchers.     

Anti-cytokine therapy in the treatment of psoriasis

Psoriasis is a chronic, inflammatory skin disease with many associated co-morbidities including diabetes, hypertension, obesity, psoriatic arthritis, and cardiovascular disease. It has long been known that psoriasis is a T cell-mediate disease and recent findings further demonstrate the important roles of the Th17 and Th22 arms of the immune system in the pathogenesis of psoriasis. Our understanding of this disease has progressed greatly and agents that target the cytokines involved in disease activity are under development or currently being used to treat psoriasis. A comprehensive review of the literature for cytokine-targeted therapies, their safety concerns, and efficacy in psoriasis are discussed here.     

Low expression of the IL-23/Th17 pathway in atopic dermatitis compared to psoriasis

The classical Th1/Th2 paradigm previously defining atopic dermatitis (AD) and psoriasis has recently been challenged with the discovery of Th17 T cells that synthesize IL-17 and IL-22. Although it is becoming evident that many Th1 diseases including psoriasis have a strong IL-17 signal, the importance of Th17 T cells in AD is still unclear. We examined and compared skin biopsies from AD and psoriasis patients by gene microarray, RT-PCR, immunohistochemistry, and immunofluorescence. We found a reduced genomic expression of IL-23, IL-17, and IFN-gamma in AD compared with psoriasis. To define the effects of IL-17 and IL-22 on keratinocytes, we performed gene array studies with cytokine-treated keratinocytes. We found lipocalin 2 and numerous other innate defense genes to be selectively induced in keratinocytes by IL-17. IFN-gamma had no effect on antimicrobial gene-expression in keratinocytes. In AD skin lesions, protein and mRNA expression of lipocalin 2 and other innate defense genes (hBD2, elafin, LL37) were reduced compared with psoriasis. Although AD has been framed by the Th1/Th2 paradigm as a Th2 polar disease, we present evidence that the IL-23/Th17 axis is largely absent, perhaps accounting for recurrent skin infections in this disease.     

Clinical, pathological and immunological features of psoriatic-like lesions affecting keratin 14-vascular endothelial growth factor transgenic mice

Up-regulation of vascular endothelial growth factor (VEGF) plays a primary role in the pathogenesis of psoriasis. Transgenic mice over-expressing VEGF under the Keratin 14 (K14) promoter develop an inflammatory skin condition with many of the pathobiological features of human psoriasis. In this work, the development of spontaneous psoriatic-like dermatitis in K14-VEGF transgenic mice was monitored from week 6 to week 44 and skin lesions were characterized clinically (application of a clinical score system comparable to the human Psoriasis Area and Severity Index), microscopically (histopathology, leukocyte subset and neoangiogensis) and immunologically (evaluation of local and systemic cytokine/chemokine profiles). Based on PASI score system, three progressive clinical phases were identified: mild acute (8-14 weeks of age), moderate subacute (15-21 weeks of age) and severe chronic-active (22-44 weeks of age) dermatitis. Microscopically, skin lesions consisted of progressive proliferative psoriatic-like dermatitis dominated by dermo-epidermal infiltrates of CD3-positive lymphocytes, an increased number of mast cells and neoangiogenesis. Both local and systemic up-regulation of pro-inflammatory (IL-12, TNF-alpha, IL-6, MCP-1 and IL-8) and regulatory (IL-10) cytokines/chemokines was observed, mainly during the later stages of disease development. The results obtained in this study further confirm the central role of VEGF over-expression in the development of psoriatic-like dermatitis. Similarly to what is reported for human psoriasis, both the local and systemic immunologic profiles observed in K14-VEGF transgenic mice suggest that a combined Th1 and Th17 response may be implicated in lesion development. The identification of three progressive stages of disease, each with peculiar clinicopathological features, renders the K14-VEGF transgenic mouse a valuable model to study novel immunotherapies for psoriasis.     

Clinical symptoms of skin, nails, and joints manifest independently in patients with concomitant psoriasis and psoriatic arthritis

This study correlated assessment tools for evaluating the severity of skin, nail, and joint symptoms in patients with psoriasis (Pso) and psoriatic arthritis (PsA). Adults with plaque Pso (with or without PsA) were enrolled from four U.S. institutions. Patients were evaluated using a novel 10-area Linear Psoriasis Area and Severity Index (XL-PASI), Psoriatic Arthritis Assessment (PsAA), Psoriatic Arthritis Screening and Evaluation Questionnaire (PASE), Nail Assessment (NA) and Joint Assessment (JA) tools, Psoriasis Weighted Extent and Severity Index (PWESI), and Lattice Physician Global Assessment (LS-PGA). Correlations between assessment tools and individual items in the assessment tools were performed. Data from 180 patients (55 with PsA) were analyzed. Highest correlations between tools (r = 0.77–0.88) were between the XL-PASI, PWESI and LS-PGA. Individual items in the XL-PASI correlated with items in the PWESI for extent skin symptoms, but not for all body areas. Overall, correlations were seen between hands and feet, between face and scalp, and between buttocks, chest, and back. Only low correlation was seen between items assessing joint symptoms with items assessing skin symptoms. These data support the notion that the complex phenotype of psoriatic disease requires instruments that assess the severity of skin, nails, and joints separately.     

Clinical and cytokine profile evaluation in Northeast Brazilian psoriasis plaque-type patients

Objective and Design

Psoriasis is a common, enigmatic, and recurrent disease. The precise etiology and pathogenesis of psoriasis are still unclear. Psoriasis has been treated as an inflammatory disorder related to an underlying Th1/Th17-dominated immune response. Interleukins are involved in the development of psoriasis lesions through Th-17-associated inflammation. Th1 and Th17 cytokines are found in skin lesions and in the peripheral blood of psoriasis patients.We sought to analyze serum levels of IL-1-β, IL-8, IL-9, IL-27, IL-29, IL-35, IFN-γ, TNF and TGF-β in patients with psoriasis and healthy control volunteers.

Material

Blood samples were collected from fifty-three patients with psoriasis and thirty-five healthy controls.

Methods

Serum cytokines concentrations were determined using an enzyme-linked immunosorbent assay.

Results

Serum IL-8, IL-9, IL-27, IL-29 and TNF levels were statistically significant in psoriasis patients. Detectable serum IL-9 levels were found in 47 patients of the 53 in the psoriasis group.

Conclusions

Interleukins-8, 27, 29 and TNF levels measured in the serum of psoriasis patients were slightly elevated as compared to healthy controls in a weakly significant way. On the other hand, there were highly significant differences in IL-9 levels between the two groups.

     

Proanthocyanidins from the bark of Metasequoia glyptostroboides ameliorate allergic contact dermatitis through directly inhibiting T cells activation and Th1/Th17 responses

ObjectiveThe leaves and bark of Metasequoia glyptostroboides are used as anti-microbic, analgesic and anti-inflammatory drug for dermatic diseases in Chinese folk medicine. However, the pharmacological effects and material basis responsible for the therapeutic use of this herb have not yet been well studied. The objectives of this study were to evaluate the anti-inflammatory effects of the proanthocyanidin fraction from the bark of M. glyptostroboides (MGEB) and to elucidate its immunological mechanisms.Materials and methodsThe anti-inflammatory activity of MGEB was evaluated using 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD) in mice. Its potential mechanisms were further investigated by determining its effects on Con A-induced T cell activation and Th1/Th17 responses in vitro.ResultsBoth intraperitoneal injection and oral administration of MGEB significantly reduced the ear swelling in DNFB-induced ACD mice. MGEB inhibited Con A-induced proliferation and the expression levels of cell surface molecules CD69 and CD25 of T cells in vitro. MGEB also significantly decreased the production of Th1/Th17 specific cytokines (IL-2, IFN-γ and IL-17) and down-regulated their mRNA expression levels in activated T-cells.ConclusionsMGEB could ameliorate ACD, at least in part, through directly inhibiting T cells activation and Th1/Th17 responses.     

Immunophenotyping of dendritic cells in lesional, perilesional and distant skin of chronic plaque psoriasis

Psoriasis affects 2.7% of the world’s population. The sequence of these events remains controversial. Because antigen presenting is necessary for T-cell activation, dendritic cells may be involved in the pathogenesis of psoriasis. To investigate their role, we examined immunophenotyping of different dendritic cells and their distribution and numbers in psoriasis patients. Immunohistochemistry of CD1a, CD11c, CD86 and BDCA2 were performed using paraffin-embedded tissue obtained from a total of 45 patients with psoriasis. Samples were taken from the lesion, perilesional and distant skin and normal skin obtained from 10 control cases. There were marked increase in the number of positive CD1a, CD11c, CD86 and BDCA2 cells in perilesional and the psoriatic skin when compared to the distant skin and they were the least in the normal control skin. So different dendritic cells subsets have a very important role in psoriasis pathogenesis especially in initiation of the plaque in the perilesional skin.     

Prevalence and Clinical Relevance of T-Helper Cells,Th17 and Th1, in Hepatitis B Virus-Related Hepatocellular Carcinoma

Background and Aims

An immune imbalance in the cytokine profile exerts a profound influence on the progression of hepatitis B virus (HBV) infections and hepatocellular carcinoma (HCC). The present study evaluated the immune status of T helper (Th) 17 and Th1 cells in patients with HBV-related and non-HBV-related HCC.

Methods

We randomly enrolled 150 patients with HCC. Blood samples and tissue samples were obtained. The distributions and phenotypic features of Th17 and Th1 cells were determined by flow cytometry and/or immunohistochemistry.

Results

Compared to corresponding non-tumor regions, the levels of Th17 and Th1 cells were significantly increased in tumors of patients with HCC (P<0.001). The intratumoral densities of IL-17-producing cells and IFN-γ-producing cells were associated with overall survival (OS, P = 0.001) and disease-free survival (DFS, P = 0.001) of patients with HCC. The ratio of Th17 to Th1 in HBV-related HCC was higher than in non-HBV-related HCC. A multivariate Cox analysis revealed that the Th17 to Th1 ratio was an independent prognostic factor for OS (HR = 2.651, P = 0.007) and DFS (HR = 2.456, P = 0.002).

Conclusions

HBV infections can lead to an imbalance in immune status in patients with HCC. An elevated Th17 to Th1 ratio may promote tumor progression. The Th17 to Th1 ratio could serve as a potential prognostic marker for scoring the severity of HCC.