Dibutyl phthalate-induced thymic stromal lymphopoietin is required for Th2 contact hypersensitivity responses.

Thymic stromal lymphopoietin (TSLP) is an IL-7-related cytokine, produced by epithelial cells, that has been linked to atopic dermatitis and asthma; however, it remains unclear how TSLP shapes the adaptive immune response that causes these allergic disorders. In this study, we demonstrate a role for TSLP in a Th2 model of contact hypersensitivity in mice. TSLP is required for the development of Th2-type contact hypersensitivity induced by the hapten FITC in combination with the sensitizing agent dibutyl phthalate. TSLPR-deficient mice exhibited a dramatically reduced response, including markedly reduced local infiltration by eosinophils, Th2 cytokine production, and serum IgE levels, following FITC sensitization and challenge. The reduced response by TSLPR-deficient mice is likely due to decreased frequency and reduced T cell stimulatory function of skin-derived Ag-bearing FITC(+)CD11c(+) dendritic cells in draining lymph nodes following FITC sensitization. These data suggest that skin-derived dendritic cells are direct or indirect targets of TSLP in the development of type 2 immune responses in the skin, where TSLP drives their maturation, accumulation in skin draining lymph nodes, and ability to induce proliferation of naive allergen-specific T cells.

Human epidermal Langerhans cells express the tight junction protein claudin-1 and are present in human genetic claudin-1 deficiency (NISCH syndrome).

Claudin-1 (CLDN1) is a structural tight junction (TJ) protein and is expressed in differentiating keratinocytes and Langerhans cells in the epidermis. Our objective was to identify immunoreactive CLDN1 in human epidermal Langerhans cells and to examine the pattern of epidermal Langerhans cells in genetic human CLDN1 deficiency [neonatal ichthyosis, sclerosing cholangitis (NISCH) syndrome]. Epidermal cells from healthy human skin labelled with CLDN1-specific antibodies were analysed by confocal laser immunofluorescence microscopy and flow cytometry. Skin biopsy sections of two patients with NISCH syndrome were stained with an antibody to CD1a expressed on epidermal Langerhans cells. Epidermal Langerhans cells and a subpopulation of keratinocytes from healthy skin were positive for CLDN1. The gross number and distribution of epidermal Langerhans cells of two patients with molecularly confirmed NISCH syndrome, however, was not grossly altered. Therefore, CLDN1 is unlikely to play a critical role in migration of Langerhans cells (or their precursors) to the epidermis or their positioning within the epidermis. Our findings do not exclude a role of this TJ molecule once Langerhans cells have left the epidermis for draining lymph nodes.

Cutting edge: Lack of evidence for connexin-43 expression in human epidermal Langerhans cells.

A provocative study has shown that viral peptides may be transferred in vitro from epithelial cells to APC through connexin-43 gap junction channels. In support of this cross-presentation pathway, the study also reported that human dendritic cells, including Langerhans cells of skin, express connexin-43. In this report we show that if this was the case, the levels of connexin-43 are below those detectable by immunofluorescence, flow cytometry, quantitative PCR of purified CD1a+ cells, and electron microscopy, raising questions about the relevance of the connexin-43-dependent mechanism for Langerhans cells of noninflamed human skin.

Langerhans cells and lymph node dendritic cells express the tight junction component claudin-1.

Claudin-1 is a critical structural component of tight junctions that have an important role in adhesive properties, barrier function, and paracellular transport of epithelia and other nonhematopoietic tissues. We found claudin-1 in murine CD207+ Langerhans cells (LC) residing in epidermis. Claudin-1 was not detected in other skin dendritic cells (DC). LC expressed claudin-1 in steady state and inflamed skin. Claudin-1 was demonstrated further in lymph node LC under steady state and inflammatory conditions, including after direct tracking with tetramethylrhodamine-isothiocyanate (TRITC). All subsets of skin draining lymph node DC defined by CD205, CD11b, CD11c, and CD8, including a presumably blood-borne lymph node resident CD8+CD207+ LC population, were claudin-1+. TRITC tracking demonstrated claudin-1 in CD207- skin migrant DC in the lymph node, suggesting upregulation of this molecule during migration or once arrived in the lymph node. Claudin-1 expression in CD207+ cells was confirmed at the protein and mRNA levels. Transforming growth factor-beta, a factor critical for the induction of LC in vitro and in vivo, stimulated the accumulation of claudin-1 mRNA and protein when added to bone marrow cells cultured with GM-CSF and IL-4. Claudin-1 may thus have an important function in adhesion and/or migration of LC.

Pharmacological prevention of serious anaphylactic reactions due to iodinated contrast media: systematic review.

OBJECTIVE: To review the efficacy of pharmacological prevention of serious reactions to iodinated contrast media. DESIGN: Systematic review. DATA SOURCES: Systematic search (multiple databases, bibliographies, all languages, to October 2005) for randomised comparisons of pretreatment with placebo or no treatment (control) in patients receiving iodinated contrast media. Review methods Trial quality was assessed by all investigators. Information on trial design, population, interventions, and outcomes was abstracted by one investigator and cross checked by the others. Data were combined by using Peto odds ratios with 95% confidence intervals. RESULTS: Nine trials (1975-96, 10 011 adults) tested H1 antihistamines, corticosteroids, and an H1-H2 combination. No trial included exclusively patients with a history of allergic reactions. Many outcomes were not allergy related, and only a few were potentially life threatening. No reports on death, cardiopulmonary resuscitation, irreversible neurological deficit, or prolonged hospital stays were found. In two trials, 3/778 (0.4%) patients who received oral methylprednisolone 2x32 mg or intravenous prednisolone 250 mg had laryngeal oedema compared with 11/769 (1.4%) controls (odds ratio 0.31, 95% confidence interval 0.11 to 0.88). In two trials, 7/3093 (0.2%) patients who received oral methylprednisolone 2x32 mg had a composite outcome (including shock, bronchospasm, and laryngospasm) compared with 20/2178 (0.9%) controls (odds ratio 0.28, 0.13 to 0.60). In one trial, 1/196 (0.5%) patients who received intravenous clemastine 0.03 mg/kg and cimetidine 2-5 mg/kg had angio-oedema compared with 8/194 (4.1%) controls (odds ratio 0.20, 0.05 to 0.76). CONCLUSIONS: Life threatening anaphylactic reactions due to iodinated contrast media are rare. In unselected patients, the usefulness of premedication is doubtful, as a large number of patients need to receive premedication to prevent one potentially serious reaction. Data supporting the use of premedication in patients with a history of allergic reactions are lacking. Physicians who are dealing with these patients should not rely on the efficacy of premedication.

The period length of fibroblast circadian gene expression varies widely among human individuals.

Mammalian circadian behavior is governed by a central clock in the suprachiasmatic nucleus of the brain hypothalamus, and its intrinsic period length is believed to affect the phase of daily activities. Measurement of this period length, normally accomplished by prolonged subject observation, is difficult and costly in humans. Because a circadian clock similar to that of the suprachiasmatic nucleus is present in most cell types, we were able to engineer a lentiviral circadian reporter that permits characterization of circadian rhythms in single skin biopsies. Using it, we have determined the period lengths of 19 human individuals. The average value from all subjects, 24.5 h, closely matches average values for human circadian physiology obtained in studies in which circadian period was assessed in the absence of the confounding effects of light input and sleep-wake cycle feedback. Nevertheless, the distribution of period lengths measured from biopsies from different individuals was wider than those reported for circadian physiology. A similar trend was observed when comparing wheel-running behavior with fibroblast period length in mouse strains containing circadian gene disruptions. In mice, inter-individual differences in fibroblast period length correlated with the period of running-wheel activity; in humans, fibroblasts from different individuals showed widely variant circadian periods. Given its robustness, the presented procedure should permit quantitative trait mapping of human period length.

Antigen-specific secretory IgA antibodies in the gut are decreased in a mouse model of food allergy.

BACKGROUND: A large body of evidence implicates IgA antibodies in the immune response to pathogens present in the gut. Whether IgA antibodies play a similar role in food allergy remains to be determined. OBJECTIVE: We sought to characterize beta-lactoglobulin (BLG)-specific serum and secretory IgA antibody production in the gut and to define the role of antigen-induced cytokines in IgA production in a murine model of food allergy. METHODS: BLG-specific IgA antibodies were measured in the sera and feces of mice anaphylactic or tolerant to BLG. The number of antibody-secreting cells in the spleen and Peyer's patches was determined by means of ELISPOT. Mesenteric lymph node cells and Peyer's patch T cells were transferred to naive mice, and antibody production in the sera and feces in recipient mice, as well as antibody-secreting cell numbers, were measured. RESULTS: Serum IgA antibody titers were strongly increased in anaphylactic mice. In contrast, BLG-specific IgA antibody titers were increased in feces but not in sera from tolerant mice. These results were correlated with an increased number of BLG-specific IgA-secreting cells in Peyer's patches from tolerant mice. The adoptive transfer of Peyer's patch CD3+ cells from tolerant mice induced an increased number of IgA-secreting cells preferentially in the Peyer's patches of naive recipient mice. Furthermore, an increase of BLG-induced IL-10 and TGF-beta levels was found at IgA production sites. CONCLUSIONS: These results suggest a role for secretory IgA in tolerance mechanisms to foods. Peyer's patch CD3+ cells are primarily involved by favoring IgA production through the release of IL-10 and TGF-beta.

Nephrogenic fibrosing dermopathy in a renal transplant recipient with tubulointerstitial nephritis and uveitis.

We report a patient with nephrogenic fibrosing dermopathy. He had chronic renal failure with arthritis, uveitis and histologically severe tubulointerstitial nephritis for which he received a renal transplant from a family relative. After an episode of acute renal failure with the transplant he developed painful, erythematous, firm papules and plaques with geographic borders on the legs, anterior thorax and elbow. A skin biopsy revealed increased fibroblast and collagen fiber content of the dermis and subcutaneous septae. Mucin deposition, sparse smooth-muscle-actin-positive cells and an increased number of CD34-positive cells in the deep dermis were found. After several weeks of hemodialysis, the lesions changed from an inflammatory to a purely sclerotic phase. The fibrocyte, a recently described circulating cell type, that is deposited in scar tissue may be involved in the pathogenesis of this novel pseudosclerodermatous skin disorder.

Lentiviral transduction of dendritic cells confers protective antiviral immunity in vivo.

Control of a viral infection in vivo requires a rapid and efficient cytotoxic-T-lymphocyte response. We demonstrate that lentivirus-mediated introduction of antigen in dendritic cells confers a protective antiviral immunity in vivo in a lymphocytic choriomeningitis virus model. Therefore, lentiviral vectors may be excellent vaccine candidates for viral infections.

Lymphocytes in Peyer patches regulate clinical tolerance in a murine model of food allergy.

BACKGROUND: Food allergy can lead to severe, potentially life-threatening anaphylactic reactions. To generate efficient strategies aimed at an active cure, a better understanding of the pathogenic mechanisms is strongly needed. OBJECTIVE: To investigate T-cell-related mechanisms of food allergy and tolerance to beta-lactoglobulin (BLG) in gut-associated lymphoid structures. METHODS: Beta-lactoglobulin-specific IgG1, IgG2a, and IgE in serum from mice anaphylactic to BLG were analyzed by ELISA and compared with those obtained in mice actively tolerized to BLG. The number of Ab-secreting cells in the spleen and in Peyer patches was determined by ELISPOT. The numbers of cytokine-producing cells after antigen-specific activation were measured by the same method. Furthermore, mesenteric lymph node cells and Peyer patches cells were transferred to naive mice, and Ab production as well as Ab-secreting cells were measured. RESULTS: Serum IgG1 and IgE Ab titers as well as IL-4-producing cell numbers were strongly increased in anaphylactic mice. IL-10 was found in Peyer patch cells from tolerant mice after BLG activation but not in anaphylactic mice. Peyer patch cells, in contrast to mesenteric lymph node cells, proliferated weakly in anaphylactic mice after antigen activation, and activation of Peyer patches was partially inhibited by tolerization. CONCLUSIONS: Our data suggest a specific role for lymphocytes in Peyer patches in tolerance to BLG. Low IL-10 production in Peyer patches may favor symptoms of food allergy.

[Anaphylaxis after injection of corticosteroid preparations--carboxymethylcellulose as a hidden allergen]. / Anaphylaxie nach Injektion von Kortikosteroidpraparaten-- Carboxymethylzellulose, ein verstecktes Allergen.

Two patients developed anaphylaxis after injection of a corticosteroid preparation containing carboxymethylcellulose (E466). In both cases skin tests yielded positive immediate type reactions to pure carboxymethylcellulose. This hydrophilic derivative of cellulose has found wide application in the pharmaceutical, cosmetics and food industry. The diagnosis is based on skin testing as 9% of the normal population was found to have serum IgE antibodies to this compound. In case of anaphylaxis after injection of corticosteroids, carboxymethylcellulose in addition to corticosteroids should be included for skin testing.

Efficient induction of CD8 T-associated immune protection by vaccination with mRNA transfected dendritic cells.

Dendritic cells are excellent targets for antigen-specific immune intervention. Here we attempted to introduce a CD8 T cell-dependent epitope into dendritic cells for presentation on major histocompatibility complex class I and induction of immunity. Murine bone-marrow-derived dendritic cells were subjected to electroporation with mRNA transcribed in vitro from a plasmid encoding lymphocytic choriomeningitis virus glycoprotein or enhanced green fluorescent protein under the control of a T7 promotor. The transfection efficiency of dendritic cells was 22 to 40%. Maturation was not inhibited by the electroporation. Dendritic cells electroporated with the appropriate antigen induced cell number-dependent in vitro proliferation in CD8 T cells expressing a transgenic receptor recognizing the 33 to 41 sequence of lymphocytic choriomeningitis virus glycoprotein in association with H-2Kb/Db, indicating correct synthesis, processing, and presentation of the epitope. Naive C57BL/6 mice vaccinated with electroporated dendritic cells and challenged with lymphocytic choriomeningitis virus were protected. Vaccination induced epitope-specific T cells as assessed by tetramer staining in blood and spleen. These results indicate that targeting dendritic cells with antigen-encoding mRNA can induce antigen-specific CD8 T cell responses as well as protective anti-viral immunity in vivo. Targeting dendritic cells with antigen-encoding mRNA may find wider application for immune intervention in disorders such as autoimmunity and cancer.

Anaphylactic reactions to tolperisone (Mydocalm).

Four patients with anaphylaxis attributed to the intake of the centrally acting muscle relaxant tolperisone hydrochloride (Mydocalm) were observed at the Emergency Department of the Geneva University Hospital between November 2001 and March 2003. All patients were middle-aged women who took tolperisone for chronic muscular pain. All reactions occurred within an hour after oral intake of this drug frequently prescribed in Switzerland. The severity of anaphylaxis ranged from urticarial reactions to shock with arterial hypotension. Prick-to-prick skin testing performed in one patient with a tablet of tolperisone diluted in water was negative. Its globally restricted commercialisation may explain the lack of reports on such adverse effects in the MedLine database. Anaphylactic reactions to this drug, however, are mentioned in other sources such as the Swiss Drug Compendium and the WHO drug reaction database. Together, these findings suggest that anaphylaxis to tolperisone is not uncommon and should be known to physicians in countries where this drug is available.

TNF-alpha induces the generation of Langerin/(CD207)+ immature Langerhans-type dendritic cells from both CD14-CD1a and CD14+CD1a- precursors derived from CD34+ cord blood cells.

CD34+ cell-derived hematopoietic precursors amplified with FLT3-ligand, thrombopoietin and stem cell factor became, after a 6-day induction with GM-CSF, IL-4 and TGF-beta1, HLA-DR+, CD1a+, CD83-, CD86-, CD80- cells. A fraction of them expressed Langerin, Lag, and E-cadherin, resembling epidermal Langerhans cells (LC). TNF-alpha added for the last 3 days only marginally induced CD83 expression, but strikingly increased the proportion of immature Langerin+CD83- LC. Langerin+CD83+ and Langerin+CD83- cells were functionally distinct, the former internalizing less efficiently Langerin than the latter. Both CD1a-CD14- and CD1a-CD14+ cells sorted from FLT3-ligand, thrombopoietin and stem cell factor cultures responded to TNF-alpha by an increase of Langerin+ cells. Thus, TNF-alpha rescued LC precursors irrespective of their commitment to the monocytic lineage. When added to GM-CSF, IL-4 and TGF-beta1 containing-cultures, LPS or IL-1beta also induced significant numbers of Langerin+CD83- immature cells displaying a low allostimulatory activity, while CD40-ligand largely promoted highly allostimulatory Langerin-CD83+ cells. Altogether, these data show that in contrast to CD40-ligand, which induced LC maturation even in presence of TGF-beta1, nonspecific proinflammatory factors such as TNF-alpha, IL-1 or LPS, essentially induced immature LC generation, and little cell activation in the presence of TGF-beta1.

CD4-independent protective cytotoxic T cells induced in early life by a non-replicative delivery system based on virus-like particles.

The relative immaturity of the neonatal immune system limits CD4(+) Th1 and cytotoxic T lymphocyte (CTL) responses, and represents a significant challenge for the development of vaccines against intracellular pathogens. In this report, we demonstrate the ability of a non-replicative delivery system based on parvovirus-like particles (VLP) to induce CTL responses in the neonatal period. A single immunization of 1-week-old BALB/c mice with recombinant VLP carrying a CD8(+) T cell determinant from lymphocytic choriomeningitis virus (VLP-LCMV) induced antigen-specific CD8(+) cytotoxic T cells that were similar to those elicited by adult immunization, as assessed by cytotoxic activity, interferon (IFN)-gamma secretion, cytotoxic precursor cell frequencies, in vitro avidity for antigen and protective activity against viral challenge. These CTL responses are elicited within 2 weeks of a single immunization, in the absence of adjuvant and independently of the presence and help of CD4(+) T cells, highlighting the potential of VLP as candidate vaccine vectors in early life.

The sesquiterpene lactone parthenolide inhibits LPS- but not TNF-alpha-induced maturation of human monocyte-derived dendritic cells by inhibition of the p38 mitogen-activated protein kinase pathway.

BACKGROUND: Dendritic cells (DCs) are the most potent antigen-presenting cells, and the manipulation of DC maturation provides a strategy for the treatment of allergic and inflammatory diseases. OBJECTIVE: In this study we examined the effect of the anti-inflammatory sesquiterpene lactone parthenolide (PTL) on DC maturation induced by LPS or TNF-alpha. METHODS: Human monocyte-derived DCs generated by means of culture with GM-CSF and IL-4 were pretreated with PTL and subsequently stimulated with LPS or TNF-alpha. RESULTS: PTL inhibited the upregulation of CD80, CD83, CD86, CD40, and MHC class II; the allostimulatory function; the production of TNF-alpha and IL-12; and the downregulation of FITC-labeled dextran uptake in human monocyte-derived DCs stimulated with LPS but not with TNF-alpha. The inhibitory effect of PTL on DC maturation was preceded by inhibition of the phosphorylation of p38 mitogen-activated protein kinase but not the nuclear translocation of NF-kappaB. CONCLUSION: These results might offer PTL not only as a promising compound for the treatment of LPS-induced disorders, including sepsis or septic shock, by inhibition of excessive DC maturation but also as a tool to further dissect the signaling pathways involved in DC maturation.