Biomedical subjects

A Scheynius

Publications and source records attributed to A Scheynius.

At least 37 records · Page 2Linked to original sources

PubMed2002

Cytokine production in nickel-sensitized individuals analysed with enzyme-linked immunospot assay: possible implication for diagnosis.

BACKGROUND: Patients with suspected allergic contact dermatitis still have to undergo patch testing for a correct diagnosis. As this has several disadvantages there is a need for additional methods, preferentially those that can be performed in vitro. Objectives To investigate the possibility of diagnosing contact allergy to nickel (Ni2+) using the enzyme-linked immunospot (ELISpot) assay that allows the analysis of cytokines at a single-cell level in ex vivo activated peripheral blood mononuclear cells (PBMC). METHODS: Eleven female patients and nine age- and sex-matched healthy volunteers participated in the study. All patients had a history of nickel allergy and a positive patch test reaction to NiSO4, while the controls' test was negative. PBMC were cultured in the presence or absence of NiCl2. Cell proliferation was measured with [3H]thymidine incorporation, and the number of cytokine-producing cells analysed with the ELISpot assay. RESULTS: The proliferative response of PBMC to Ni2+, expressed as stimulation index, was significantly higher in the nickel-allergic patients than in the control group. Using the ELISpot assay, we found that PBMC from nickel-allergic individuals responded to Ni2+ with significantly greater production of interleukin (IL)-4, IL-5, IL-13 and interferon-gamma, but not IL-12, compared with the healthy controls. The number of IL-4- and IL-5-producing cells correlated with the number of IL-13-producing cells in the nickel-allergic patients, but Ni2+-induced PBMC proliferation did not correlate with the number of cytokine-producing cells for any of the cytokines tested. CONCLUSIONS: Our results indicate that the ELISpot assay could be a tool in the discrimination between nickel-allergic and non-allergic individuals.

Adult↗

PubMed2002

IgE is expressed on, but not produced by, fetal cells in the human placenta irrespective of maternal atopy.

The prevalence of atopic diseases in children has increased during the last decades. Atopic symptoms usually appear early in life. This implies an early priming for atopic disease, possibly even at the fetal level. We therefore compared the presence and production of IgE in the local in utero environment during pregnancy in atopic and non-atopic women. Eighty-six women were included in the study. Fifty women were demonstrated to be atopics, based on clinical symptoms of atopic disease together with a positive Phadiatop and/or skin prick test. Placentas from these term pregnancies were obtained. Slices covering the full thickness of the placenta were cut clockwise around the umbilical cord and were analysed with immunohistochemistry. Surprisingly, numerous IgE+ cells, located primarily in the fetal villous stroma, were detected in a majority of the investigated placentas irrespective of the atopy of the mother or maternal or fetal total serum IgE levels. The placental IgE could not be demonstrated to be bound to IgE receptors, but was shown to be bound to fetal macrophages, possibly via FcgammaRI. No evidence was found for local fetal IgE production, although cells producing epsilon transcripts were occasionally detected in the decidua. We describe here the novel finding of numerous IgE+ cells in the human placenta, suggesting an hitherto unknown role for IgE in a successful pregnancy outcome, irrespective of whether or not the mother is atopic.

Adult↗

PubMed2001

Truncated thioredoxin (Trx80) induces production of interleukin-12 and enhances CD14 expression in human monocytes.

Human thioredoxin (Trx) is the major 12-kd cellular disulfide-reductase that on secretion acts as a cocytokine with several interleukins. Truncated Trx with the 80 N-terminal residues (Trx80), also present in plasma, was by itself a mitogenic cytokine for human peripheral blood mononuclear cells (PBMC). This study investigated which cells in PBMC are targets of recombinant Trx80. Purified human CD14(+) monocytes, but not B or T cells, in a synthetic medium were activated to differentiation by Trx80 as measured by flow cytometry of surface antigens because exposure to 100 nM Trx80 increased expression of CD14, CD40, CD54, and CD86. Proliferation of the monocytes was increased in a dose-dependent manner by Trx80 in concentrations ranging from 10 nM to 1 microM. Trx or interleukin (IL) 2 did not induce proliferation or expression of surface antigens on monocytes. Trx80 alone induced secretion of IL-12 from CD40(+) monocytes in the PBMC cultures and this effect was enhanced by IL-2. Trx80 and IL-2 together were strongly synergistic to induce secretion of interferon-gamma in PBMC cultures. The results showed that Trx80 is a potent cytokine for normal human monocytes and directs the immune system in favor of a Th1 response via IL-12 production.

Antigens, CD↗

PubMed2001

Effectiveness of occlusive bedding in the treatment of atopic dermatitis--a placebo-controlled trial of 12 months' duration.

BACKGROUND: Several studies on avoidance of house-dust-mite (HDM) and cat allergens have been carried out, most of them in asthmatic patients and only a few in patients with atopic dermatitis (AD). No study so far has focused on which subgroup of AD patients benefits from avoidance measures. METHODS: Forty adult patients with AD completed the 12-month avoidance study. They were divided into an active treatment (n = 22) and a placebo (n = 18) group. Active treatment comprised use of polyurethane-coated cotton encasings for bedding, and placebo use of cotton covers. Patients came for regular checkups during the 12-month period, when eczema severity was assessed and blood samples were analyzed for total IgE, HDM- and cat-specific IgE and soluble CD30 (sCD30) in serum. Dust samples were collected from mattresses before treatment and after 3, 6, and 12 months, and analyzed for content of HDM and cat allergen. RESULTS: Eczema severity decreased significantly in both groups (P < 0.001), with a more pronounced decrease in patients with active covers. The HDM exposure decreased significantly in the active treatment group (P < 0.001), and the levels of HDM-specific IgE were reduced (P<0.05). Exposure to cat allergens was unchanged in the active treatment group but decreased, albeit not significantly (P=0.19), in the placebo group. sCD30 levels were significantly reduced in both groups (P<0.001). Patients not sensitized to HDM allergens benefited from the bedcovers as much as sensitized patients. CONCLUSIONS: Occlusive bedding significantly reduced HDM exposure in bed (P<0.001) and eczema severity, and sCD30 levels decreased significantly (P<0.001). Patients not sensitized to HDM and not exposed to HDM allergens benefited equally from use of the bedcovers, a result which could be due to a reduction of other important allergens, superantigens, or irritants in bed. We therefore recommend the use of bedcovers as part of treatment for AD.

Adult↗

PubMed2001

The allergenic yeast Malassezia furfur induces maturation of human dendritic cells.

BACKGROUND: The yeast Malassezia furfur (M. furfur), present in the normal microflora of human skin, can act as an allergen that incites specific IgE reactivity and T cell proliferation in atopic dermatitis (AD) patients. The role of antigen presenting dendritic cells (DCs) in the onset and maintenance of AD is not well established. OBJECTIVE: The objective of the present study was to assess whether the interaction of M. furfur with human DCs will result in DC maturation, cytokine production and lymphocyte proliferation. METHODS: Monocyte-derived dendritic cells (MDDCs) were generated from human peripheral blood. Immature MDDCs were cultured with or without M. furfur or plastic beads, and with or without CD40L stimulation. Interaction of yeast cells by MDDCs was studied by time-lapse photography and cytokines were detected in culture supernatants with ELISA. The ability of MDDCs pre-incubated with M. furfur to induce proliferation in autologous lymphocytes was measured by [(3)H]-thymidine incorporation. RESULTS: Time-lapse photography showed that the majority of immature MDDCs internalized whole M. furfur yeast cells within 1 h. The presence of M. furfur induced maturation (CD83 expression) of MDDCs, and up-regulation of the costimulatory molecules CD80 and CD86. Production of TNF-alpha, IL-1 beta and IL-18 by MDDCs increased significantly (P < 0.05 for TNF-alpha and IL-1 beta, and P < 0.01 for IL-18) after the addition of M. furfur, while IL-10 and IL-12p70 levels remained unaltered. The CD40L-stimulated IL12p70 production by MDDCs was decreased in the presence of M. furfur (P < 0.05). Finally, immature MDDCs pre-incubated with M. furfur induced a proliferative response in autologous CD14-depleted peripheral blood mononuclear cells, in a dose-dependent manner. CONCLUSION: The data indicate that immature MDDCs can internalize the opportunistic yeast M. furfur. This process was associated with MDDC maturation, production of pro-inflammatory and immunoregulatory cytokines, which might favour induction of a Th2-type immune response, and a capacity to stimulate lymphocyte proliferation. This chain of events most likely contributes to the inflammatory reaction in AD.

Allergens↗

PubMed2001

Thiols decrease cytokine levels and down-regulate the expression of CD30 on human allergen-specific T helper (Th) 0 and Th2 cells.

The thiol antioxidant N-acetyl- L-cysteine (NAC), known as a precursor of glutathione (GSH), is used in AIDS treatment trials, as a chemoprotectant in cancer chemotherapy and in treatment of chronic bronchitis. In vitro, GSH and NAC are known to enhance T cell proliferation, production of IL-2 and up-regulation of the IL-2 receptor. The 120-kD CD30 surface antigen belongs to the tumour necrosis factor (TNF) receptor superfamily. It is expressed by activated T helper (Th) cells and its expression is sustained in Th2 cells. We have analysed the effect of GSH and NAC on the cytokine profile and CD30 expression on human allergen-specific T cell clones (TCC). TCC were stimulated with anti-CD3 antibodies in the presence of different concentrations of GSH and NAC. Both thiols caused a dose dependent down-regulation of IL-4, IL-5 and IFN-gamma levels in Th0 and Th2 clones, with the most pronounced decrease of IL-4. Furthermore, they down-regulated the surface expression of CD30, and the levels of soluble CD30 (sCD30) in the culture supernatants were decreased. In contrast, the surface expression of CD28 or CD40 ligand (CD40L) was not significantly changed after treatment with 20 m M NAC. These results indicate that GSH and NAC favour a Th1 response by a preferential down-regulation of IL-4. In addition, the expression of CD30 was down regulated by GSH and NAC, suggesting that CD30 expression is dependent on IL-4, or modified by NAC. In the likely event that CD30 and its soluble counterpart prove to contribute to the pathogenesis in Th2 related diseases such as allergy, NAC may be considered as a future therapeutic agent in the treatment of these diseases.

Acetylcysteine↗

PubMed2001

Presence of CD30(+) and CD30L(+) cells in human placenta and soluble CD30 levels in cord blood are independent of maternal atopy.

The intrauterine environment is characterized by a Th2 dominance during pregnancy, a milieu that also promotes atopic allergy. The aim of this study was to compare the presence of CD30, a molecule associated with Th2 related disorders such as atopic allergy, and its ligand (CD30L) in placenta in order to investigate if the placenta environment differs between atopic and non-atopic women. Serum concentrations of soluble CD30 (sCD30) from the mothers and their newborns were also elucidated. There were no differences in the immunohistochemical expression of CD30 and CD30L in placenta from atopic (n=28) compared with non-atopic (n=37) women. CD30 was expressed on the decidual stromal cells alone, while CD30L, previously not described in placenta, was detected on macrophage-like HLA-DR(+) cells throughout the mesenchymal chorionic villi. Serum sCD30 in atopic mothers was significantly elevated compared with serum sCD30 in non-atopic mothers (P< 0.05), while sCD30 levels in cord blood were similar in both groups independently of maternal atopic heredity. We suggest that sCD30 in cord blood and CD30 expression by decidual cells may reflect the Th2 environment surrounding the fetus, and both CD30 and CD30L could have immune regulatory functions in placenta.

Decidua↗

PubMed2001

A double-blinded, comparative study of the effects of short preseason specific immunotherapy and topical steroids in patients with allergic rhinoconjunctivitis and asthma.

BACKGROUND: Both specific immunotherapy (SIT) and nasal steroid (NS) have been shown to effectively reduce symptoms of allergic rhinitis. Although a number of investigators have convincingly shown anti-inflammatory effects of both treatments in separate studies, few comparative studies have been performed. OBJECTIVE: The purpose of this study was to compare the effects of preseason SIT with a standardized allergen extract and NS in seasonal allergic disease (rhinoconjunctivitis and asthma). METHODS: We examined 41 patients allergic to birch pollen, 21 with rhinoconjunctivitis and 20 with both rhinoconjunctivitis and asthma; they were treated in a randomized, double-blinded comparative study with birch SIT and NS (budesonide 400 microg daily). Bronchial hyperresponsiveness was measured before and during the season. Changes in eosinophil number, eosinophil cationic protein, and eosinophil chemotactic activity (ECA) in peripheral blood were investigated. RESULTS: Symptoms of rhinoconjunctivitis increased significantly less in the NS-treated patients than in the SIT-treated patients during the final 2 weeks of the season (P = .03 and P = .04, respectively). Seasonal peak expiratory flow values decreased significantly only in the NS-treated patients (P = .01). In the NS-treated patients, bronchial hyperresponsiveness increased significantly during the season (P = .0001); however, SIT treatment prevented seasonal PC(20) increase in the asthmatic patients. Measurement of blood eosinophils, eosinophil cationic protein, and eosinophil chemotactic activity demonstrated significant seasonal increase only in the NS-treated asthmatic patients. CONCLUSION: Treatment with NS was more effective than short-course preseason SIT in reducing symptoms of rhinoconjunctivitis; however, the 2 therapies were equivalent in terms of the need for rescue medication. SIT prevented seasonal increase in bronchial hyperresponsiveness, eosinophil number, eosinophil cationic protein, and eosinophil chemotactic activity only in asthmatic patients. The mechanisms underlying bronchial hyperresponsiveness developing during allergen exposure in rhinitis might be different from those operating in asthma.

Administration, Intranasal↗

PubMed2001

A hypoallergenic derivative of the major allergen of the dust mite Lepidoglyphus destructor, Lep d 2.6Cys, induces less IgE reactivity and cellular response in the skin than recombinant Lep d 2.

BACKGROUND: The major allergen of the dust mite Lepidoglyphus destructor, Lep d 2, has been produced as a recombinant allergen (rLep d 2) with IgE reactivity both in vivo and in vitro. A modified form of rLep d 2 (rLep d 2.6Cys) obtained by site-directed mutagenesis has been shown to have a reduced IgE reactivity in vitro. In this study we have compared the ability of rLep d 2 and rLep d 2.6Cys to elicit positive skin prick tests and cellular responses among L. destructor-sensitized subjects. METHODS: Seventeen subjects were skin prick-tested with rLep d 2, rLep d 2.6Cys, histamine and negative controls and 17-20 h later skin biopsy specimens were taken from the skin prick-tested sites. The biopsy specimens were stained immunohistochemically for EG2+, CD3+, CD1a+, mast cell tryptase+, and IgE+ cells. Dermal cell infiltrates were judged in hematoxylin and eosin staining. Total IgE and allergen-specific IgE were determined by CAP-RAST. RESULTS: Compared to rLep d 2, rLep d 2.6Cys induced significantly smaller and fewer skin prick test reactions (p < 0.001) and dermal cell infiltrates (p < 0.05). Further, rLep d 2.6Cys induced fewer EG2+ cells (p < 0.001) but more tryptase+ cells (p < 0.05) than rLep d 2. A positive RAST to rLep d 2 was obtained for 88.2% of the subjects, while only 35.2% displayed a positive RAST to rLep d 2.6Cys. CONCLUSION: This study demonstrates that rLep d 2.6Cys is less able to evoke IgE-mediated reactions and cellular responses, as measured both in skin and in serum, than rLep d 2. In the future this hypoallergenic derivative may be a promising candidate molecule for immunotherapy of L. destructor-allergic patients.

Adult↗

PubMed2000

Analysis of epsilon germline transcripts and IL-4 mRNA expression in the adenoids suggests local IgE switching.

BACKGROUND: We have previously observed more frequent occurrence of IgE+ and FcepsilonRI+ cells in adenoids of atopic than nonatopic children. To investigate the hypothesis that the adenoids are involved in IgE production, we analyzed the levels of epsilon germline (epsilonGL), IL-4, and IFN-gamma transcripts in the adenoids in relation to atopy and presence of ear disease. METHODS: Adenoidectomy was performed on 19 atopic and 18 nonatopic children (median age 5 years, range 2-12 years) suffering from otitis media with effusion (OME) (n = 16) or obstructive adenoids hyperplasia (AH) (n = 21). The levels of epsilonGL transcripts, IL-4, and IFN-gamma mRNA were analyzed by competitive reverse transcriptase-PCR. RESULTS: EpsilonGL transcript levels in the adenoids were found to be dependent on IL-4 mRNA expression (P < 0.01) and serum IgE levels (P < 0.05) (R2 = 0.32, n = 37). IL-4 mRNA expression was associated with epsilonGL transcript levels (rs = 0.32, P = 0.05, n = 37), especially among patients with AH (rs = 0.53, P = 0.01, n = 21). No significant differences in IL-4 and IFN-gamma mRNA levels were observed between the groups. CONCLUSIONS: This study supports an IL-4-induced class switch to IgE production in the adenoids that might be of importance for inflammatory reactions in the upper respiratory tract.

Adenoids↗

PubMed2000

Positive atopy patch test reactions to Pityrosporum orbiculare in atopic dermatitis patients.

BACKGROUND: Pityrosporum orbiculare, although a part of our normal cutaneous microflora, can cause skin infections and induce specific immunoglobulin (Ig) E antibodies in atopic dermatitis patients. P. orbiculare is therefore considered to be one of the trigger factors for atopic dermatitis. OBJECTIVE: To investigate if P. orbiculare can induce an eczematous reaction in atopic dermatitis patients, seborrhoeic dermatitis patients and healthy controls. METHODS: Fifteen atopic dermatitis patients, eight seborrhoeic dermatitis patients and eight healthy controls were patch tested with extract of P. orbiculare on non-lesional, tape-stripped skin of the back. NaCl was used as a negative control. The patch tests were evaluated after 24, 48 and 72 h. Skin biopsies were taken from P. orbiculare patch test sites at 24 h and 72 h, from NaCl patch test sites at 72 h, from non-lesional skin and, in the atopic dermatitis patients, also from lesional skin. The skin biopsies were investigated with immunohistochemical techniques. P. orbiculare-specific IgE in serum was analysed with RAST. RESULTS: Specific IgE to P. orbiculare was found in serum from 13/15 atopic dermatitis patients and in eight of them a positive patch test reaction to P. orbiculare was observed, with a maximal reaction at 48 h. Significantly higher serum levels of P. orbiculare-specific IgE were detected in patch test-positive compared with patch test-negative atopic dermatitis patients (P < 0. 01). The seborrhoeic dermatitis patients and healthy controls were RAST and patch test-negative for P. orbiculare. In the patch test-positive atopic dermatitis patients an infiltration of CD4+ T cells and eosinophils was observed at the P. orbiculare patch test sites together with an upregulation of ICAM-1 and HLA-DR expression. CONCLUSIONS: P. orbiculare can induce an eczematous reaction in sensitized atopic dermatitis patients and may be an important trigger factor in these patients. The P. orbiculare patch test can be of diagnostic value in this subgroup of atopic dermatitis patients.

Adolescent↗

PubMed2000

Uptake of the yeast Malassezia furfur and its allergenic components by human immature CD1a+ dendritic cells.

Atopic dermatitis (AD) is a chronic inflammatory skin disease with increasing prevalence, though still little is known of the pathomechanisms and the causes of the disease. Patients with AD often have specific IgE reactivity to the yeast Malassezia furfur (M. furfur), present in the normal microflora on human skin. To investigate the possible interaction of immature and mature antigen-presenting dendritic cells with the yeast M. furfur and its allergenic components. Monocyte-derived dendritic cells (MDDCs) generated from human peripheral blood were allowed to interact with FITC-labelled whole M. furfur yeast cells, M. furfur extract, a recombinant allergen from M. furfur designated rMal f 5 and M. furfur mannan, in the absence of IgE antibodies. Interaction and uptake were detected using flow cytometry and confocal laser scanning microscopy. Internalization of M. furfur yeast cells and yeast components by immature MDDCs was found using confocal laser scanning microscopy. Results from flow cytometric studies showed that a median of 94% (range, 65-98%) of the immature CD1a+ MDDCs were M. furfur extract positive, 81% (75-97%) rMal f 5 positive and 93% (62-98%) mannan positive. Mature CD1a+ MDDCs were significantly less efficient in this respect, with the corresponding figures only 26% (6-37%, P < 0.01), 6% (2-15%, P < 0.05) and 32% (9-50%, P < 0.01), respectively. Uptake of the non-glycosylated rMal f 5 by immature CD1a+ MDDCs was decreased to 27% (15-38%) by inhibition of pinocytosis. The binding of M. furfur extract and mannan was inhibited in a dose-dependent manner by methyl-alpha-D-mannopyranoside, suggesting uptake via the mannose receptor. Human immature CD1a+ MDDCs can efficiently take up M. furfur and allergenic components from the yeast in the absence of IgE antibodies, implying that sensitization of AD patients to M. furfur can be mediated by immature dendritic cells in the skin.

Allergens↗

PubMed2000

Crosslinking of CD30 on activated human Th clones enhances their cytokine production and downregulates the CD30 expression.

Signalling through CD30 has been shown to mediate pleiotropic effects, depending on the type of target cell. In the present study, we have used the agonistic anti-CD30 monoclonal antibodies (MoAb) M44 to study phenotypic changes in human T-cell clones of Th1 and Th2 type. Alterations in the surface expression of CD30, CD28 and CD40L following CD30 stimulation were analyzed after 24 h, and the cytokine production after CD30 crosslinking was measured at 48 h. We observed a clear reduction of surface expression of CD30 after treatment with the M44 MoAb. Our results also indicate that CD28 is significantly down modulated in the Th2 clones after CD30 crosslinking (P < 0.05, n = 5) whereas no apparent alteration was observed in the expression of CD40L. When the concentration of cytokines was measured in the supernatants after CD30 stimulation, elevated levels of interleukin (IL)-4 and IL-5 were observed in the Th2 clones, and elevated levels of interferon (IFN)-gamma in the Th1 clones. The enhanced cytokine production after CD30 crosslinking supports the presumption of CD30 functions as a positive regulator in activated T cells.

Allergens↗

PubMed2000

Cloning, characterization and expression of complete coding sequences of three IgE binding Malassezia furfur allergens, Mal f 7, Mal f 8 and Mal f 9.

Malassezia furfur, formerly known as Pityrosporum orbiculare or P. ovale, is a yeast that colonizes human skin. Normally, this yeast is nonpathogenic but under the influence of predisposing factors it may induce IgE reactivity in patients with atopic dermatitis. Approximately 40-65% of atopic dermatitis patients have IgE antibodies and/or skin reactivity against M. furfur and a higher T-cell response against this yeast is found in atopic dermatitis patients than in healthy individuals. By making a cDNA library displayed on a phage surface, we previously cloned five different IgE-binding proteins, Mal f 5, Mal f 6, MF 7, MF 8 and MF 9, from this yeast. The cDNAs encoding these allergens were sequenced and expressed in Escherichia coli. The sequences of MF 7, MF 8 and MF 9 were not full length (missing their 5'-ends) giving only partial gene products. To obtain complete cDNA sequences, we performed RACE-PCR to amplify the 5'-ends of each cDNA. These PCR products were sequenced and analyzed. The coding sequences of Mal f 7, Mal f 8 and Mal f 9 encode proteins with ORFs of 141 (16.2 kDa), 179 (19.2 kDa) and 126 (14.0 kDa) amino-acid residues, respectively. None of the putative proteins showed significant sequence homology with other known proteins in the searched database. The proteins encoded by the complete cDNA sequences were expressed in E. coli as recombinant proteins. Immunoblotting and radioallergosorbant test data showed that all of the expressed recombinant proteins have the ability to bind serum IgE from atopic dermatitis patients and furthermore, the M. furfur extract could specifically inhibit this IgE binding.

Adolescent↗

PubMed2000

Expression of cystic fibrosis transmembrane conductance regulator in liver tissue from patients with cystic fibrosis.

The authors examined the expression of cystic fibrosis transmembrane conductance regulator (CFTR) and its relationship to histopathological changes in cystic fibrosis (CF) liver tissue. Immunohistochemistry was used to examine expression of CFTR, intercellular adhesion molecule-1 (ICAM-1) and liver cell-type markers in liver cryosections in 11 patients with CF-associated liver disease, and non-CF controls with (n = 17) and without (n = 3) liver disease. In CF patients prominent inflammatory infiltrates were not found, yet hepatic stellate cells were identified within fibrotic areas around bile ducts. Proliferating bile ducts displayed ICAM-1 immunoreactivity in 3 cases, but bile ducts were otherwise negative. In 2 patients homozygous for R764X and for 1112delT no CFTR immunoreactivity was detected. Bile-duct epithelial cells in patients carrying the DeltaF508 mutation displayed aberrant cytoplasmic immunolocalization of CFTR, as determined with confocal laser scanning microscopy, in contrast to the distinct CFTR expression at the luminal surface seen in controls. No clear relationship between CFTR expression and fibrosis or inflammation was evidenced in CF patients. In conclusion, these findings are consistent with an impairment of DeltaF508 CFTR processing in intrahepatic biliary epithelium. ICAM-1 expression on bile-duct epithelial cells and inflammatory infiltrates were rare findings in CF liver tissue, indicating that immunological mechanisms are unlikely to be involved in initiation of CF-associated liver disease.

Adolescent↗

PubMed1999

Targeting of human dendritic cells by autologous NK cells.

NK cells have the capacity to spontaneously kill tumor cell lines, in particular cell lines of hemopoietic origin. In contrast, they do not generally kill nontransformed autologous cells. However, here we demonstrate that short-term activated polyclonal human NK cells, as well as human NK cell lines, efficiently lyse autologous dendritic cells (DC) derived from peripheral blood monocytes as well as Langerhans-like cells derived from CD34+ stem cells isolated from umbilical cord blood. Lysis of autologous DC by short-term activated NK cells and NK cell lines was dependent on granule exocytosis, since total abrogation of lysis was observed in the presence of EGTA. Induction of DC maturation by LPS, monocyte conditioned media (MCM), or stimulation through CD40 ligand (CD40L) rendered the DC less susceptible to lysis by NK cells. Infection of DC with influenza virus was likewise associated with a reduced susceptibility to lysis by NK cells. Thus, susceptibility to lysis by autologous NK cells is a particular property of immature DC. The present results are discussed in relation to the ability of DC to interact with NK cells and to the ability of NK cells to regulate development of specific immunity.

Animals↗

PubMed1999

Atopy in children of families with an anthroposophic lifestyle.

BACKGROUND: Increased prevalence of atopic disorders in children may be associated with changes in types of childhood infections, vaccination programmes, and intestinal microflora. People who follow an anthroposophic way of life use antibiotics restrictively, have few vaccinations, and their diet usually contains live lactobacilli, which may affect the intestinal microflora. We aimed to study the prevalence of atopy in children from anthroposophic families and the influence of an anthroposophic lifestyle on atopy prevalence. METHODS: In a cross-sectional study, 295 children aged 5-13 years at two anthroposophic (Steiner) schools near Stockholm, Sweden, were compared with 380 children of the same age at two neighbouring schools in terms of history of atopic and infectious diseases, use of antibiotics and vaccinations, and social and environmental variables. Skin-prick tests were done for 13 common allergens, and we took blood samples from children and their parents for analysis of allergen-specific serum IgE-antibodies. FINDINGS: At the Steiner schools, 52% of the children had had antibiotics in the past, compared with 90% in the control schools. 18% and 93% of children, respectively, had had combined immunisation against measles, mumps, and rubella, and 61% of the children at the Steiner schools had had measles. Fermented vegetables, containing live lactobacilli, were consumed by 63% of the children at Steiner schools, compared with 4.5% at the control schools. Skin-prick tests and blood tests showed that the children from Steiner schools had lower prevalence of atopy than controls (odds ratio 0.62 [95% CI 0.43-0.91]). There was an inverse relation between the number of characteristic features of an anthroposophic lifestyle and risk of atopy (p for trend=0.01). INTERPRETATION: Prevalence of atopy is lower in children from anthroposophic families than in children from other families. Lifestyle factors associated with anthroposophy may lessen the risk of atopy in childhood.

Adolescent↗

PubMed1999

Immunologic characterization of natural and recombinant Mal f 1 yeast allergen.

BACKGROUND: Individuals with atopic dermatitis (AD) often have IgE antibodies against protein components of Malassezia furfur. The cDNA encoding one of these proteins (Mal f 1) has recently been cloned and sequenced. OBJECTIVE: We sought to express recombinant Mal f 1 (rMal f 1) allergen in large quantities by using different expression systems. The primary aim was to characterize the IgE-binding properties of rMal f 1 in comparison with its natural counterpart in M furfur extract. METHODS: We have expressed and purified Mal f 1 from prokaryotic (Escherichia coli) and eukaryotic cells (baculovirus-infected insect cells). The rMal f 1 produced in both systems has been tested for the ability to be recognized by IgE from patients with specific serum IgE to M furfur by using immunoblotting and the Pharmacia CAP System RAST FEIA. RESULTS: Sixty-one percent of sera from 95 patients showed positive RAST responses to the rMal f 1 produced in the baculovirus expression system and 43% to the E coli -produced rMal f 1. Both the E coli - and baculovirus-produced proteins can specifically inhibit IgE binding to a 36-kd protein band (Mal f 1) in immunoblotting, indicating that the recombinant proteins contain the majority, if not all, the IgE-binding epitopes of Mal f 1. Recombinant Mal f 1 is able to release histamine from basophils of an atopic individual. CONCLUSION: We have expressed and purified rMal f 1, which can bind IgE in a way resembling natural Mal f 1. The ability to produce recombinant allergens with similar properties to their native counterparts has many potential uses, such as accurately diagnosing causes of IgE-mediated allergy.

Allergens↗