A recombinant fusion protein derived from dog hookworm inhibits autoantibody‐induced dermal–epidermal separation ex vivo

The proteins secreted by parasitic nematodes are evolutionarily optimized molecules with unique capabilities of suppressing the immune response of the host organism. Neutrophil inhibitory factor (NIF), which is secreted by the dog hookworm Ancylostoma caninum, binds to the β2 integrin CD11b/CD18, which is expressed on human neutrophils, eosinophils, monocytes and macrophages and inhibits neutrophil‐dependent lung injury and neutrophil invasion of ischaemic brain tissue. Neutrophils are key players in the pathogenesis of subepidermal autoimmune blistering diseases (sAIBDs), and their pathogenic activities are crucially dependent on β2 integrin functionality. Based on the template of single‐stranded, dimerizing antibody derivatives, which are already used in cancer treatment, we designed a novel biologic, NIF‐IGHE‐CH4, comprising NIF and the dimerizing but otherwise inert constant heavy subdomain 4 (CH4) of human IgE (IGHE). This molecule was evaluated in a variety of in vitro assays, demonstrating its ability to inhibit pathogenically relevant neutrophil functions such as migration, adhesion and spreading, and release of reactive oxygen species. Finally, we confirmed that NIF‐IGHE‐CH4 inhibits blister formation in an ex vivo assay of sAIBD. These results suggest that NIF‐IGHE‐CH4 is a novel potential anti‐inflammatory drug for the treatment of neutrophil‐mediated diseases such as sAIBDs. This study promotes the drugs from bugs concept and encourages further research and development focused on turning parasite proteins into useful anti‐inflammatory biologics.     

Abundant immunoglobulin E‐positive cells in skin lesions support an allergic etiology of atopic dermatitis in the elderly

Background/Objectives Atopic dermatitis (AD) in the elderly is gradually increasing in industrialized countries in association with the aging of society. We report herein four cases of elderly AD {three extrinsic [immunoglobulin (Ig)E‐mediated allergy]; one intrinsic (non‐IgE‐allergy)} in which we investigated the presence of IgE+ cells in lesional skin. Methods/Results Single immunohistochemical and double immunofluorescence stainings were performed for skin biopsy specimens from AD patients and non‐atopic control subjects with chronic eczema. In the lesional lichenified skin of patients with extrinsic elderly AD, numerous IgE+ cells were found among inflammatory cells infiltrates in the upper dermis. Comparative analysis of single immunohistochemistry results using serial paraffin and/or frozen sections found that many IgE+ cells showed identical distributions to tryptase+ mast cells. IgE+ cells coincident with CD1a+ Langerhans cells in the epidermis were found in small numbers only in frozen sections. Double immunofluorescence staining for IgE and CD11c revealed cells coexpressing IgE and CD11c with a dendritic morphology in the papillary and upper dermis. These IgE+ mast cells and IgE+ CD11c+ cells were also found in cured normal‐looking skin from a patient with extrinsic elderly AD after successful treatment. Although only a few weakly positive IgE+ cells were detected, no IgE+CD11c+ cells were found in specimens from patients with intrinsic elderly AD or non‐atopic chronic eczema. Conclusion IgE‐mediated allergic inflammation may play an important role in the pathobiology of elderly AD, similar to other age groups of AD.     

Basophils and mast cells are crucial for reactions due to epicutaneous sensitization to ovalbumin

The prevalence of food allergies worldwide has increased recently. Epicutaneous sensitization to antigen could be a method to study food allergy. To clarify the mechanisms of food allergy, we established a mouse model of epicutaneous sensitization using ovalbumin (OVA). BALB/c mice were sensitized by three‐time application of OVA to tape‐stripped skin (1‐week sensitization at 2‐week intervals) and oral challenge of OVA undertaken. Rectal temperature was monitored. Blood and tissue (skin and jejunum) of challenged mice were taken. Numbers of mast cells (MCs) and basophils were counted. Serum and/or tissue levels of OVA ‐specific IgE and IgG antibodies and several cytokines were measured using enzyme‐linked immunoassay kits. MC and basophil depletion experiments were undertaken. In OVA/epicutaneous‐sensitized and orally challenged mice, systemic anaphylaxis (as evidenced by reduced rectal temperature) was observed. Levels of OVA‐specific IgE and IgG antibodies were increased in these mice, as were increased number of MCs and basophils. Serum levels of MC protease 1 were increased significantly. Basophil and MC depletion experiments revealed that they both participate in reactions. Increased production of thymic stromal lymphopoietin (TSLP) at skin sites of OVA sensitization was noted. We speculate that TSLP produced from epidermal cells during antigen sensitization can enable basophils to promote a T helper (Th)2 immune reaction, leading to and systemic anaphylaxis by antigen‐specific IgE‐bearing MCs. This TSLP‐basophils‐MC axis could be a novel therapeutic target against food allergy.     

Comparative in situ topoproteome analysis reveals differences in patch test‐induced eczema: cytotoxicity‐dominated nickel versus pleiotrope pollen reaction

Please cite this paper as: Comparative in situ topoproteome analysis reveals differences in patch test‐induced eczema: cytotoxicity‐dominated nickel versus pleiotrope pollen reaction. Experimental Dermatology 2010; 19: 511–517. Abstract: A subgroup of patients with atopic eczema develops acute eczematous reactions to type I allergy‐inducing agents such as pollen that clinically resemble type IV allergies induced by haptens like metal ions. To clarify the underlying immunologic mechanisms, this study was designed to map the inflammatory in situ topoproteome of eczematous responses to grass/birch pollen and nickel by using atopy patch test (APT) and nickel patch test (NPT) as an appropriate clinical model, respectively. Biopsies from NPT (n = 6) and APT (n = 6) with positive reactions at 72 h were analysed by multiple epitope ligand cartography (MELC), which enabled to investigate coexpression of 49 different epitopes immunohistochemically in a single given tissue section. Colocalisation of IgE and FcεRI was investigated by confocal microscopy. Compared with APT responses, NPT reactions were dominated by cytotoxic TIA‐1 + and CD8 + T cells. In contrast, the immune response in APT reactions appeared more pleiotrope – as detected by colocalisation analysis. Multiple combinatorial molecular phenotype (CMP) motifs containing naive, early maturation and memory T cell (CD45RA, CD7, CD44, CD45R0), and general activation markers (CLA, HLA‐DR, CD13, CD29, CD58, CD71, CD138) were significantly higher expressed in APT when compared with NPT reactions. APT response was confirmed to be accompanied by IgE bound to FcεRI. In summary, our results demonstrate that the NPT reaction is clearly dominated by cytotoxic events, while the APT reaction to pollen grains is more heterogeneous and elicits a combined humoral and cellular immune reaction.     

Activated status of basophils in chronic urticaria leads to interleukin-3 hyper-responsiveness and enhancement of histamine release induced by anti-IgE stimulus

BACKGROUND: Basophils and mast cells are the main target cells in chronic idiopathic urticaria (CIU). Besides the basopenia, intrinsic defects of the anti-IgE cross-linking signalling pathway of basophils have been described in CIU. OBJECTIVES: We sought to investigate the profile of expression of activation markers on basophils of patients with CIU and to explore the effect of interleukin (IL)-3 priming upon anti-IgE cross-linking stimuli through expression of activation markers and basophil histamine releasability. METHODS: Evaluation of the surface expression of FcepsilonRIalpha, CD63, CD203c and CD123 on whole blood basophils of patients with CIU undergoing autologous serum skin test (ASST) was performed by flow cytometry. The effect of pretreatment with IL-3 in the anti-IgE response was analysed by the expression of basophil activation markers and histamine release using enzyme-linked immunosorbent assay. RESULTS: Blood basophils of patients with CIU were reduced in number and displayed increased surface expression of FcepsilonRIalpha, which was positively correlated with the IgE serum levels. Upregulation of expression of both surface markers CD203c and CD63 was verified on basophils of patients with CIU, regardless of ASST response. High expression of IL-3 receptor on basophils was detected only in ASST+ patients with CIU. Pretreatment with IL-3 upregulated CD203c expression concomitantly with the excreting function of blood basophils and induced a quick hyper-responsiveness to anti-IgE cross-linking on basophils of patients with CIU compared with healthy controls. CONCLUSIONS: Basophils of patients with CIU showed an activated profile, possibly due to an in vivo priming. Functionally, basophils have high responsiveness to IL-3 stimulation, thereby suggesting that defects in the signal transduction pathway after IgE cross-linking stimuli are recoverable in subjects with chronic urticaria.     

Characterization of the T cell response in allergic contact dermatitis caused by corticosteroids

Background Delayed allergic hypersensitivity reactions have classically been described as type IV reactions, which are caused by T cells; however, the respective roles of CD4⁺ and CD8⁺ cells are yet to be defined. A central role for CD8⁺ cytotoxic T cells as effector cells has been suggested. Objectives To determine the type of T cell involved in corticosteroid allergy. Methods We analysed the kinetics of T cell recruitment and the cytokine production profile in positive patch tests of 27 corticosteroid‐sensitized patients, as compared with control sites and control subjects. Skin biopsies, collected at 8, 24 and 48 hr following drug application, were embedded in paraffin for histological and immunohistological staining, and, in some cases, also deep‐frozen for gene expression analyses. Results CD3⁺ T cells were rapidly recruited in concert with the positivity of the patch test sites. High levels of interleukin (IL)‐4, IL‐5 and, to a lesser extent, interferon‐γ suggested that both Th2 and Th1 cytokines were implicated. IL‐4 was also produced by γδ T cell receptor (TCR) lymphocytes. Conclusions This study showed that, in allergic contact dermatitis caused by corticosteroids, the inflammatory infiltrate is composed of CD3⁺ T cells with a predominant Th2 cytokine profile, among which IL‐4 is also produced by γδ TCR lymphocytes.     

Characterization of CD 200-receptor expression in the murine epidermis

CD 200 is a widely expressed transmembrane glycoprotein that transmits an inhibitory signal after ligation of the structurally homologous CD 200-receptor-1 (CD 200 R1). Recently, we showed that CD 200 is expressed on keratinocytes and plays a role in protecting hair follicles from autoimmune attack. Here, we report the characterization of cell surface and mRNA expression of CD 200 R1 by cells of the murine epidermis. In addition, we report mRNA expression for other members of the CD 200 R-family (R2-R4) by quantitative real-time RT-PCR. Variable levels of CD 200 R1, R2, R3, and R4 mRNA were detected in bulk epidermal cell suspensions. Freshly isolated Langerhans cells (LC) preferentially expressed CD 200 R1. Consistent with an inhibitory role for CD 200:CD 200 R1 interaction, LC obtained from mice deficient in CD 200 (CD 200(-/-)) were in a heightened state of activation as compared with wild-type (CD 200(+/+)) cells. Freshly isolated dendritic epidermal T cells (DETC) expressed low levels of CD 200 R1, R2, and R3 mRNA, but they preferentially increased cell surface and mRNA expression of CD 200 R1 upon activation in vitro. In functional assays using sub-optimal CD3 signaling, immobilized CD 200 inhibited DETC proliferation and cytokine secretion. Collectively, these results suggest that CD 200:CD 200 R interactions may play a role in regulating both LC and DETC in cutaneous immune reactions.     

Usefulness of the CD63 basophil activation test in detecting Anisakis hypersensitivity in patients with chronic urticaria: diagnosis and follow‐up

Background. The basophil activation test (BAT) has been recently described as a useful in vitro tool for diagnosis of allergy to Anisakis species in patients with acute urticaria. Aim. To evaluate the relationship between sensitization to Anisakis simplex and chronic urticaria (CU), using flow cytometry analysis of in vitro BAT. Methods. A. simplex sensitization was evaluated in patients with CU (n = 57) and in atopic (n = 22) and healthy controls (n = 20) by means of skin prick test (SPT), specific IgE and Anisakis‐induced BAT using a triple‐labelled strategy with anti‐CD123, anti‐human leucocyte antigen DR and anti‐CD63 antibodies. During a follow‐up period of 6 months in 10 patients with CU who accepted a fish‐free dietary regimen, the diagnostic performance of the in vivo and in vitro methods was calculated, and changes in specific IgE and BAT were evaluated with respect to clinical response. Results. A significant association between CU and A. simplex sensitization was found, with an overall prevalence of 75.4% in patients with CU (43/57) compared with 18% (4/22) and 10% (2/20) of the atopic and healthy controls, respectively (P < 0.0001). BAT (cut‐off > 13%) had the highest sensitivity and specificity, with significantly better ability than specific IgE testing for the identification of A. simplex sensitization in patients with CU. During the 6‐month follow‐up, clinical improvement was seen in all patients, and specific IgE and BAT results decreased to normal values in 6/10 (60%) and 10/10 (100%) patients, respectively. Conclusions. BAT can be considered a reliable new in vitro method to evaluate A. simplex hypersensitivity in patients with CU, supplementing standardized procedures in both diagnosis and follow‐up.     

Dermal infiltrates of cutaneous T‐cell lymphomas with epidermotropism but not other cutaneous lymphomas are abundant with langerin+ dendritic cells

Background The Langerhans cell (LC) hypothesis suggests that cutaneous T‐cell lymphomas (CTCL) are diseases of chronic T‐cell stimulation by LC‐mediated antigen presentation. Objective To investigate a broad panel of CTCL and cutaneous B‐cell lymphomas (CBCL) for the spatial association of langerin⁺ dendritic cells (DC) with T and B cells in the skin, respectively. Methods Fifty‐five specimens of CTCL and 10 of CBCL were double‐stained with monoclonal antibodies against langerin and CD3 or CD20, respectively, and evaluated by confocal laser scan microscopy. Results Dermal infiltrates in mycosis fungoides (n = 38), primary cutaneous CD4+ small/medium‐sized pleomorphic T‐cell lymphoma (n = 3) and primary cutaneous peripheral T‐cell lymphoma, unspecified (n = 3) were characterized by a high frequency of dermal langerin⁺ DCs. These cells were exclusively present in the malignant infiltrates. No direct co‐localization of CD3 and langerin could be resolved. Dermal langerin⁺ cells were detected only in one of six primary cutaneous anaplastic large cell lymphomas (C‐ALCL), characterized by epidermotropism. In other C‐ALCL cases (five of six), in lymphomatoid papulosis (n = 3), subcutaneous panniculitis‐like T‐cell lymphoma (n = 2), and all variants of CBCL no dermal langerin⁺ DCs could be found. Conclusions Langerin⁺ DCs are abundant in the dermal infiltrates of T‐cell lymphomas with specific involvement of the epidermis. This might indicate that immature LC and neoplastic T cells interact and gives rise to further studies to characterize the phenotype of the langerin⁺ cell population described here and its role in the pathology of CTCL.     

25-hydroxyvitamin D3 1alpha-hydroxylase splice variants in human skin

There is increasing evidence that the basophil does not only play an important role in acute allergic reactions but also in the pathogenesis of chronic allergic disorders. Here we show that human basophils express melanocortin receptors (MC-Rs) and respond to alpha-melanocyte-stimulating hormone (alpha-MSH) with regulation of proallergic cytokine expression and modulation of basophil activation markers. Using primers against all known MC-R subtypes we demonstrate that the human basophil cell line KU812 expresses MC-1R. Expression of MC-1R on the surface of KU812 cells was confirmed by FACS analysis using an anti-MC-1R antibody. The MC-1R expressed by KU812 cells was functionally active as alpha-MSH induced intracellular cAMP in a dose-dependent manner. Moreover, alpha-MSH abrogated the effect of calcium ionophore A23187 on IL-4 mRNA expression in these cells. The relevance of the above findings was corroborated by showing that MC-1R surface expression is also detectable in basophils of leukocyte suspensions derived from whole human blood. Most interestingly, alpha-MSH was capable of suppressing the inductive effect of fMLP on surface expression of the basophil activation marker CD63 in leukocyte suspensions of atopic individuals. Likewise, alpha-MSH significantly blocked grass pollen-induced up-regulation of CD63 in leukocyte suspensions of patients with grass pollen allergy. Our findings highlight a novel functional dimension of alpha-MSH. In addition, MSH peptides may become a novel future therapeutic avenue in treating human allergic diseases.     

Levels of immunoglobulin E specific to the major food allergen and chemokine (C‐C motif) ligand (CCL)17/thymus and activation regulated chemokine and CCL22/macrophage‐derived chemokine in infantile atopic dermatitis on Ishigaki Island

Atopic dermatitis (AD) is a multifactorial T‐helper (Th)2‐mediated skin disease frequently associated with elevated serum immunoglobulin (Ig)E and food allergy is also a Th2‐ and IgE‐mediated adverse immunological reaction. Our previous study indicated the relation of egg allergy history and disease severity of AD. Thus, the purpose of the study was to investigate the levels of IgE specific to major food allergens (egg, milk, wheat) and Th2 chemokines (chemokine [C‐C motif] ligand [CCL]17/thymus and activation regulated chemokine [TARC] and CCL22/macrophage‐derived chemokine [MDC]) and the relationship between them. A total of 743 nursery school children were enrolled. Dermatologist‐based physical examination and a questionnaire survey were also conducted. Significantly increased levels of disease severity markers (CCL17/TARC and CCL22/MDC) were confirmed in children with AD. The levels of CCL22/MDC in all of the children were markedly high compared with those reported in adults. IgE specific to egg white, ovomucoid, wheat and mite antigen were significantly higher in the AD group than in the non‐AD group. Among them, IgE specific to egg allergens were well associated with disease severity markers, and IgE specific to ovomucoid seemed particularly well correlated with the presence of egg allergy history. In conclusion, the markedly high level of CCL22/MDC in children as compared with those reported in adults may partly explain the AD‐prone nature of children and their spontaneous remission afterwards. Mild but significant correlation of IgE specific to egg allergens and Th2 chemokines may explain correlation of disease severity and comorbidity of egg allergy in our previous study.     

Two decades of occupational (meth)acrylate patch test results and focus on isobornyl acrylate

Background Wheat protein derivatives are used in a variety of products worldwide. Gluten is commercially used ‘as is' or with modifications such as hydrolysis, which is carried out to overcome its insolubility. Several cases of contact urticaria following exposure to hydrolysed wheat protein (HWP) in cosmetics or of anaphylaxis caused by deamidated gluten in food or non‐food products have been described. Objectives To evaluate the types of HWP that have higher allergenicity for percutaneous sensitization. Methods We enrolled 7 patients with wheat‐dependent exercise‐induced anaphylaxis who had been sensitized to HWP primarily through the percutaneous and/or the rhinoconjunctival route by using facial soap containing HWP. Reaction to wheat proteins was confirmed by IgE immunoblotting and basophil CD203c expression with six HWP variants. Results The IgE of all the patients reacted to HWPs composed of large polypeptide aggregates. High molecular weight (MW) HWPs were also found to induce significant enhancement of basophil CD203c expression. Conclusions HWPs composed of large polypeptide aggregates possibly induce sensitization to a greater degree than lower‐MW HWPs. Basophil surface CD203c expression is useful for evaluating the allergenicity of HWPs.     

Basophil CD63 expression assay on highly sensitized atopic donor leucocytes-a useful method in chronic autoimmune urticaria

BACKGROUND: The autoimmune subclass of chronic idiopathic urticaria (CU) has been characterized by the occurrence of biologically relevant IgG antibodies against the IgE molecule or the alpha chain of the high-affinity Fcepsilon receptor (FcepsilonRIalpha) on basophils and mast cells. These antibodies are usually detected by autologous serum skin testing and confirmed by histamine release studies, immunoblotting, or enzyme-linked immunosorbent assay, but not always. OBJECTIVES: To detect autoantibodies to the FcepsilonRIalpha in sera of CU patients by a modified serum-induced basophil activation test measured by flow cytometry (FCM) and to evaluate the relationship between the in vitro functional test, the autologous serum skin test (ASST), and the serum levels of IgE, eosinophil cationic protein (ECP) and antithyroid antibodies. METHODS: Sera of 30 patients with CU and 26 patients with systemic autoimmune diseases (systemic lupus erythematosus, dermatomyositis) were tested for CD63 activation marker expression on basophils by FCM. Leucocytes from two highly sensitized atopic donors (D(A1,) D(A2)) and one non-atopic donor (D(NA)) were incubated with patients' sera and double-labelled with anti-IgE and anti-CD63 antibodies. Subsequently, the percentage of CD63-expressing basophils was determined by using FCM. In all CU patients an ASST was carried out and the serum IgE, and ECP levels and antithyroid antibodies were evaluated. RESULTS: Twelve patients had a positive ASST and 14 patients a positive CD63 expression assay. There was a strong correlation between the ASST and CD63 assay. Sera from patients with systemic autoimmune diseases did not raise positive CD63 expression on basophils. There was a moderate negative correlation between the occurrence of atopic serum markers (IgE, ECP) and the ability of sera to induce CD63 expression on basophil cells of D(A2) (P < 0.05). The female sex was preponderant and antithyroid antibodies were more frequent. CONCLUSIONS: Our new technical observation demonstrates that basophils of highly sensitized atopic donors can be successfully used without priming with IL-3 for the in-vitro flow cytofluorimetric diagnosis of CU. With this investigation the characterization of the autoimmune origin of CU is based on an objective in vitro technique.     

Prevalence of food avoidance and food allergy in Chinese patients with chronic urticaria

Summary Background Food avoidance is common among Chinese patients with chronic urticaria because food allergy is considered to be the cause of disease. The benefit of food avoidance and its relationship with food allergy is unknown. Objectives The aims of this study were to examine the prevalence and effect of food avoidance and food allergy in patients with chronic urticaria. Methods Four hundred and ninety‐four patients with chronic urticaria, who attended Peking University Third Hospital from January 2009 to December 2010, were studied. Food avoidance and its effect were investigated with a detailed questionnaire. Food allergy was diagnosed by serum food‐specific immunoglobulin E (IgE), elimination diet based on food‐specific IgE, and open food challenge. Results One hundred and fifty‐eight patients (32%) avoided fish, shrimp, crab, lamb or beef prior to evaluation and 82·9% of them reported food avoidance ineffective. Out of 341 patients tested for serum food‐specific IgE, 75 (22%) were positive, with soy, peanut, beef, lamb, chicken, crab and shrimp as the leading allergens. Chronic urticaria induced by food allergy was found in only 2·8% of patients. Conclusions The prevalence of food avoidance is high and mostly ineffective in Chinese patients with chronic urticaria. Foods avoided do not correspond to serum food‐specific IgE. The incidence of IgE‐mediated urticaria, as demonstrated by open food challenge, is low. Physicians and patients should be aware of unnecessary dietary avoidance while seeking treatment of chronic urticaria.     

PPL and MDM skin test: New test kit is helpful in detecting immediate‐type allergy to beta‐lactams

Background: The diagnosis of PPL (major determinant) and MDM (minor determinant) sensitization as relevant allergens in beta‐lactam allergy has been recently hampered by withdrawal from the market of formerly available test kits. We investigated a new PPL/MDM test kit in the work‐up of beta‐lactam allergy. Patients and Methods: 15 patients with history of beta‐lactam allergy were investigated for specific IgE and received patch, skin prick (SPT) and intracutaneous tests (ICT; immediate and late readings) using the relevant beta‐lactams. In addition the new test kit was used for parallel SPT and ICT. Results: 14 women and 1 man (16–73 years) with immediate (n = 7), delayed (n = 7) or unclear (n = 1) reactions to beta‐lactams 8–300 months previously (penicillin G/V n = 3, aminopenicillins n = 7, cephalosporins n = 4, unknown n = 2) were tested. In patients with immediate type reactions, n = 2 had specific IgE, n = 4 reacted to the new test kit (n = 3 MDM, all of whom reacted exclusively to this test, n = 1 PPL).Two patients with non‐immediate reactions reacted to other beta‐lactams. Conclusions: Our data show that the new test kit may be helpful in detecting patients with immediate type allergy to beta‐lactams. Without this test, in those three patients reacting exclusively to MDM, and oral provocation test would have been necessary to clarify their allergy. Data from larger groups of patients are needed to determine the sensitivity and specificity of this test kit.     

Interleukin‐10 secretion from CD14+ peripheral blood mononuclear cells is downregulated in patients with acne vulgaris

Background Acne is a common chronic inflammatory dermatosis of the pilosebaceous unit. It is characterized by seborrhoea, comedone formation and an inflammatory response consistent with defective cellular immunity to Propionibacterium acnes. Objectives The objective of this study was to investigate the immune reactivity of patients with acne compared with healthy controls by examining the response of peripheral blood mononuclear cells (PBMCs) to stimulation with P. acnes. Particular focus was placed upon measuring the production of interleukin (IL)‐10, which has an established immunoregulatory role. Patients and methods Venous blood was collected from 47 patients with acne and 40 age‐ and sex‐matched healthy controls with no prior history of acne. PBMCs were cultured and their cytokine response to P. acnes investigated. Results Proinflammatory IL‐8 and tumour necrosis factor (TNF)‐α secretion from PBMCs was higher in patients with acne when stimulated with P. acnes. In contrast, a statistically significant reduction in PBMC secretion of anti‐inflammatory IL‐10 in patients with acne was identified. The impaired production of IL‐10 by PBMCs from patients with acne was confined to CD14+ cells presumed to be monocytes. The ability of CD14 cells from patients with acne to phagocytose P. acnes bacteria was also observed to be defective but the addition of exogenous IL‐10 to PBMC cultures restored phagocytic activity. Conclusions These data suggest that patients with acne have a proinflammatory cytokine milieu and crucially are unable to contain early inflammatory changes due to a specific defect in immunosurveillance, namely low monocyte IL‐10 production. Our observations raise the possibility that acne therapeutics might profitably target IL‐10 both as a regulator of proinflammatory cytokines and in augmenting the CD14+ cell phagocytic response.     

Human HMC-1 mast cells exclusively express the FcγRII subtype of IgG receptor

Because of their localization at the interface of the internal and external environment mast cells play a crucial role in the immune response and in inflammatory reactions. Effects may be mediated not only by the high-affinity IgE receptor, but also by IgG receptors. Since in rodent mast cells signal transduction via the Fcγ receptor family has been shown, we analysed the expression of surface receptors for IgG on the human mast cell line HMC-1. It was shown by flow cytometric analysis that HMC-1 constitutively expressed the FcγRII/CD32 subtype whereas FcγRI/CD64 and FcγRIII/CD16 were not expressed. This exclusive expression of the FcγRII subtype of IgG receptor is similar to the expression pattern of basophils, although concerning cell surface molecules HMC-1 rather seem to resemble monocytes. In contrast to monocytes the expression profile on HMC-1 did not change upon stimulation with IL-4, TNFα, IFNγ, PMA or salbutamol. Moreover, the mast cell-activating cytokine SCF and the calcium ionophore A23187 did not modulate the FcγR profile in this study. To assess the importance of the exclusive FcγRII expression on HMC-1, we investigated whether the production of the cytokine TNFα is modulated via FcγRII activation or if an increase in intracellular calcium could be observed. No significant modulation of TNFα release or of intracellular free calcium after crosslinking of FcγRII by heat-aggregated IgG or by a second antibody was observed. It remains to be clarified whether this low-affinity subtype for the IgG receptor is involved in antigen-dependent sensitization of human tissue mast cells resulting in secretion of immunoregulatory cytokines. This mechanism may be important for disease states associated with circulating or tissue-bound immune complexes. Received: 26 February 1996     

Epidermal growth factor receptor tyrosine kinase inhibitors induce CCL2 and CCL5 via reduction in IL‐1R2 in keratinocytes

Please cite this paper as: Epidermal growth factor receptor tyrosine kinase inhibitors induce CCL2 and CCL5 via reduction in IL‐1R2 in keratinocytes. Experimental Dermatology 2010; 19 : 730–735. Abstract: Epidermal growth factor receptor tyrosine kinase (EGFR‐TK) is a transducer of mitogenic signals, and is involved in the pathogenesis and progression of a number of cancers, including non‐small cell lung cancer (NSCLC). Gefitinib is an EGFR‐TK inhibitor that is clinically used to treat NSCLC; however, this drug frequently causes adverse effects, including skin eruptions. The mechanism underlying these skin reactions is elusive, although it is assumed that they are caused by the inhibition of EGFR‐TK signalling in epidermal and adnexal cells. In this article, we demonstrate by immunocytochemistry that the skin lesions of patients treated with oral gefitinib had higher expression of CCL2 and CCL5 compared to normal human epidermis. Further, PD153035, a gefitinib prototype, induced CCL2 and CCL5 mRNA and protein expression in HaCaT and HSC‐1 keratinocyte cell lines with or without interleukin‐1 (IL‐1) treatment in vitro. PD153035 also reduced the levels of interleukin‐1 receptor 2 (IL‐1R2), an IL‐1 decoy receptor. Moreover, we demonstrate that reduction in IL‐1R2 by RNA interference increased IL‐1‐mediated CCL2 and CCL5 mRNA and protein expression. Taken together, our data strongly suggest that IL‐1‐mediated signalling is activated to induce the high expression of CCL2 and CCL5 via reduction in IL‐1R2 in the skin lesions caused by gefitinib.     

CD30+ clonal T‐cell lymphoid proliferation of the skin in a patient with hypereosinophilic syndrome

We report a hitherto undescribed unusual CD30+ clonal T‐cell proliferation in a 46‐year‐old man with the lymphocytic variant of hypereosinophilic syndrome with a 17‐year history of pruritus, generalized persistent papulonodular skin lesions and peripheral blood hypereosinophilia. A skin biopsy showed an eosinophil‐rich infiltrate with small to medium‐sized CD30+ lymphocytes and Churg‐Strauss granulomas. Peripheral blood flow cytometry revealed an aberrant T‐cell clone which, molecular genetically, was identical to the T‐cell clone detected in the skin. No genetic aberrations of platelet‐derived growth factor receptor alpha (PDGFRA), FIP1L1‐PDGFRA, PDGFRB or FGFR1 were found. The skin lesions showed transient response to systemic and topical corticosteroids. The skin lesions represent cutaneous involvement by clonal T‐cells in hypereosinophilic syndrome and differ from known cutaneous CD30+ lymphoproliferative disorders.