Biomedical subjects

M Schlaak

Publications and source records attributed to M Schlaak.

At least 37 records · Page 2Linked to original sources

PubMed2000

Serum level of soluble tumour necrosis factor receptor II (75 kDa) indicates inflammatory activity of sarcoidosis.

OBJECTIVES: Tumour necrosis factor alpha (TNFalpha) is a key cytokine involved in granuloma formation of sarcoidosis. Since soluble TNF receptors (sTNF-R) are known to inhibit TNF effects, we were interested in whether they are elevated in the serum of sarcoidosis patients. METHODS: We determined serum levels of sTNF-R I (55 kDa) and sTNF-R II (75 kDa) in 49 patients with sarcoidosis and 22 controls. The clinical course of the disease was re-evaluated in a follow-up after (mean +/- SE) 6.8 +/- 6.6 months. RESULTS: sTNF-R I (3.1 +/- 1.1 ng mL-1, P < 0.05) and sTNF-R II (5.5 +/- 2.7 ng mL-1, P < 0.0005) were significantly elevated in sarcoidosis compared with controls (2.4 +/- 0.7 and 3.0 +/- 1.3 ng mL-1, respectively). Interestingly, both sTNF receptors were significantly higher in the serum of patients with active compared with inactive sarcoidosis (P < 0.005 and P < 0.0005, respectively). Furthermore, serum sTNF-R II levels were significantly higher in sarcoidosis patients with advanced radiological types II and III. In 10 patients, serum sTNF-R levels were obtained before and after systemic corticosteroid therapy and we observed a significant decrease of sTNF-R II (P < 0.02), whereas sTNF-R I levels were not reduced significantly. CONCLUSIONS: Both types of sTNF receptors are elevated in the serum of sarcoidosis patients with active disease, but only the sTNF-R II seems to be useful for monitoring the inflammatory activity of the disease.

Adrenal Cortex Hormones↗

PubMed2000

Familial sarcoidosis is linked to the major histocompatibility complex region.

Sarcoidosis is a systemic granulomatous disorder associated with high CD4+ cell activity, but no pathogen is detectable. Clustering in families occurs, and the existence of a genetic predisposition to sarcoidosis is widely accepted. The major histocompatibility complex (MHC) is believed to contribute to this susceptibility. Many studies testing this hypothesis have produced conflicting results. We have genotyped 122 affected siblings from 55 families for seven DNA polymorphisms that flank and cover the MHC region on chromosome 6, and for HLA-DPB1, a candidate gene for granulomatous disorders. Multipoint nonparametric linkage (NPL) analysis showed linkage (NPL score > 2.5; p < 0.006) for the entire MHC region with a maximum NPL score of 3.2 (p = 0.0008) at marker locus D6S1666 in the Class III gene cluster. There was a significant excess of marker haplotype sharing among affected siblings. However, the frequency of HLA-DPB1 alleles on 104 shared chromosomes did not differ from that of a control group of founders from the family panel. Transmission disequilibrium was found for allele DPB1*0201, but only nine families contributed to this result. We conclude that genes of the MHC are involved in the genetic predisposition to sarcoidosis, but HLA-DPB1 alone does not sufficiently explain this fact.

Alleles↗

PubMed2000

Trichostatin A modulates expression of p21waf1/cip1, Bcl-xL, ID1, ID2, ID3, CRAB2, GATA-2, hsp86 and TFIID/TAFII31 mRNA in human lung adenocarcinoma cells.

Lung adenocarcinoma cells treated for 16 h with trichostatin A (TSA), an inhibitor of histone deacetylases, and untreated cells were analyzed with respect to differential gene expression. Complex hybridization of cDNA arrays revealed repression of Bcl-xL, CRAB2 and TFIID/TAFII31 as well as induction of p21waf1/cip1, GATA-2, hsp86, ID1, ID2 and ID3 mRNA expression, which could be verified by Northern blotting. ID2 induction was further confirmed by Taqman realtime quantitative RT-PCR. The described alterations of gene expression due to TSA renders the lung adenocarcinoma cells susceptible to induction of apoptosis.

Adenocarcinoma↗

PubMed2000

Trichostatin A-mediated regulation of gene expression and protein kinase activities: reprogramming tumor cells for ribotoxic stress-induced apoptosis.

Recently we described a new signal transduction-based tumor therapeutic strategy involving first sensitization of tumor cells by trichostatin A (TSA), an inhibitor of histone deacetylation, and thereafter efficient apoptotic triggering by ribotoxic agents, which activate stress-activated protein kinases. In the present work we investigate the molecular basis of the sensitization step in this therapeutic model system and describe TSA-induced changes in mRNA and protein expression of several candidate genes identified previously by complex hybridization. Furthermore, activities of 15 different protein kinases were followed after TSA application, using a new filter-based technique (PhosphoSpots-Assay). The obtained data suggest that TSA induces pro-apoptotic genes like ID1, ID2, ID3, and down-regulates anti-apoptotic genes like Hsp27 and Bcl-xL, thereby shifting the cellular equilibrium from life to death. Furthermore, activities of calcium/calmodulin-dependent kinase II and protein kinase C, which have been assigned pro-apoptotic function in other systems, are induced.

Apoptosis↗

PubMed2000

Human alveolar epithelial cells type II are capable of regulating T-cell activity.

Alveolar epithelial cells type II (AEC-II) express MHC class II on their surface, an important prerequisite for antigen presentation. However, accessory signals are required for an efficient T-cell activation. We therefore isolated AEC-II from tumor-free sections of human lungs obtained by lobectomy/pneumectomy and purified the cells by magnetic-activated cell sorting. Furthermore, we tested the expression of CD54, CD58, CD80, and CD86 on AEC-II and evaluated their accessory function (AF) in cell culture using a coculture of interleukin-2 (IL-2), releasing Jurkat cells and AEC-II. An increased AF is documented by an elevated IL-2 release and expressed as accessory index (AI). In 33 experiments the AF of AEC-II proved to be highly variable. AI ranged between 0.3 and 17.1 with a median of 1.4 (0.3-17.1). Forty-four percent (4-77) of the AEC-II expressed HLA-DR, 44% (12-89%) of the cells expressed CD58, and CD54 was expressed by 55% (16-89%). AEC-II also expressed CD80 and CD86 (38% [0-77%] and 40% [4-68%], respectively). Interestingly, AEC-II released high levels of TGF beta (1730 pg/mL [771-5876]) and the accessory index could be increased (approximately 2-fold) by the addition of neutralizing anti-TGF beta antibodies or radiation. Thus, type II alveolar cells express costimulatory molecules and are able to deliver costimulatory signals for T cells, providing evidence that AEC-II are able to act as antigen-presenting and immunoregulatory cells of the lung. Additionally, the accessory function of AEC-II is under the control of endogenously released TGF beta.

Antigen-Presenting Cells↗

PubMed2000

In vitro release of interleukin-15 by broncho-alveolar lavage cells and peripheral blood mononuclear cells from patients with different lung diseases.

IL-15 shares several biological activities with IL-2 and uses the b and g chain of the IL-2 receptor. In addition to its T-cell stimulating capacity, IL-15 exhibits regulatory properties on macrophage proinflammatory cytokine release. IL-15 is released by non-lymphoid cells, e.g. muscle cells, fibroblasts and monocytes/macrophages. In many lung diseases alveolar macrophages (AM) are activated and release pro- inflammatory cytokines. We asked whether IL-15 is released ex vivo by AM and peripheral blood mononuclear cells (PBMC) from patients with inactive sarcoidosis (PSi), active sarcoidosis (PSa), tuberculosis (TB), hypersensitivity pneumonitis (HSP), cryptogenic fibrosing alveolitis (CFA) and pneumonia (PN). Additionally, we examined the kinetics of the IL-15 release of these cells. During 24 hours of culture, AM from controls (CO) released 3.8 +/- 1.9 pg/ml (mean +/- SD) of IL-15, which was significantly lower than in most of the patient groups (PSa: 8.7 +/- 3.9 pg/ml, TB: 8.4 +/- 1.9 pg/ml, CFA: 5.7 +/- 1.5 pg/ml, and PN: 7. 8 +/- 2.6 pg/ml) except PSi (4.0 +/- 2.6 pg/ml) and HSP (9.3 +/- 9.5 pg/ml). PBMC from patients with PSa released significantly more IL-15 than PBMC from CO (10.8 +/- 8.9 pg/ml versus 6.9 +/- 2.2 pg/ml) whereas PBMC IL-15 release of the other groups did not differ from CO (TB: 5.7 +/- 1.4 pg/ml; CFA: 4.6 +/- 1.6 pg/ml; HSP: 4.9 +/- 3.8 pg/ml). Kinetic studies revealed a minor peak after 5 hours and a major peak from 12 hours to 35 hours for AM and PBMC. In summary, AM from all patient groups but the PSi and the HSP group released increased levels of IL-15, although the total amount of this cytokine is very low.

Alveolitis, Extrinsic Allergic↗

PubMed2000

Effect of proinflammatory cytokines on interleukin-8 mRNA expression and protein production by isolated human alveolar epithelial cells type II in primary culture.

Alveolar epithelial cells type II (AEC-II) are ideally situated to regulate the recruitment and activation of different types of cells through the production of chemokines in response to inflammatory stimulation from the alveolar space. We hypothesized that these cells are important producers of interleukin-8 (IL-8) in the lung. This lead us to investigate the capacity of isolated human AEC-II cells to release IL-8 and whether this IL-8 release is regulated by proinflammatory cytokines, i.e. IL-1 beta, TNF-alpha and IFN-gamma. We isolated AEC-II from tumor-free sections of human lungs obtained by pneumectomy and purified the cells by magnetic activated cell sorting. For control experiments the AEC-II-like cell line A549 was used. IL-8 concentration was measured by ELISA in supernatants of unstimulated and LPS-, IL-1 beta-, TNF-alpha- and IFN-gamma- stimulated cells. IL-8 mRNA expression was evaluated by RT-PCR. Spontaneous IL-8 mRNA expression and protein secretion by AEC-II were significantly higher in comparison with A549 cells. TNF-alpha increased both IL-8 mRNA expression and protein production, whereas IL-1 beta slightly increased IL-8 release but did not change mRNA expression in AEC-II. LPS and IFN-gamma did not influence IL-8 expression in AEC-II and A549 cells. These results show considerable differences between A549 cell and AEC-II. The latter are capable of producing IL-8 under the control of proinflammatory cytokines. Our findings demonstrate that the modulation of IL-8 release in AEC-II may have an important impact on the immunoreactivity of these cells during pulmonary inflammation in vivo.

Cells, Cultured↗

PubMed1999

Purification of morphologically and functionally intact human basophils to near homogeneity.

Certain studies on basophils require highly purified functionally intact cell preparations. Here, a three-step procedure is described that meets these requirements. The procedure consists of a Ficoll density gradient step, counterflow elutriation and negative selection by magnetic cell sorting (MACS). The mean purity of basophils obtained from 30 donors was 97.6+/-3.96% with a viability of 99.6+/-0.83%. The recovery rate was 49.7+/-15.6%. The cells had a normal morphological appearance as assessed by May-Grünwald-stained cytospins and were functionally intact as shown by their unaltered capacity to release histamine and interleukin 4 (IL-4) following immunological activation. This procedure is a clear improvement over currently available techniques and should facilitate future investigations on basophils.

Basophils↗

PubMed1999

Lymphocyte transformation test for the evaluation of adverse effects of antituberculous drugs.

The usefulness of the lymphocyte transformation test (LTT) for the analysis of adverse reactions to antituberculous drugs was evaluated. - The LTT was performed with isoniazid and rifampicin in 15 tuberculosis and 2 MOTT (Mycobacteria other than tuberculosis)-infection patients who suffered drug reactions, in 23 patients without any adverse reactions, in 7 controls previously exposed to antituberculous drugs, and in 14 controls who had never been exposed. 4/15 of the hepatotoxic reactions only showed a positive LTT with rifampicin, 3/15 only with isoniazid, and in 8/15 the LTT was negative. In an anaphylactoid shock reaction the LTT was extremely exaggerated for both rifampicin and isoniazid. In patients without any side effects only one slightly increased LTT due to isoniazid was observed. Two healthy controls with previous contact to these drugs showed a positive LTT for isoniazid, one of those with both rifampicin and isoniazid. The LTT was negative in all control persons without any former contact to antituberculous medications. In most cases hepatotoxicity seems to be a pure toxic reaction without the participation of cellular immune mechanisms. LTT can be useful for identifying the drug responsible for immunological side effects.

Adult↗

PubMed1999

Dietary lectins can induce in vitro release of IL-4 and IL-13 from human basophils.

Dietary lectins, present in beans and other edible plant products, pose a potential threat to consumers due to their capacity to induce histamine release from basophils. In this study, we analyzed the capacity of 16 common, in particular dietary, lectins to induce human basophils to secrete IL-4 and IL-13, the key promoters of Th2 responses and IgE synthesis. Several of the lectins, especially concanavalin A, lentil lectin, phytohemagglutinin, Pisum sativum agglutinin and Sambucus nigra agglutinin, triggered basophils to release IL-4 at concentrations of up to 1 ng/10(6) basophils. Lectins with high IL-4-inducing capacity also stimulated the release of IL-13 and histamine. Lectin-induced IL-4 and IL-13 release reached a maximum after 4-6 h and more than 18 h, respectively. Affinoblotting revealed that lectins with the capacity to induce mediator release bind to IgE, suggesting IgE binding as initial step of signal generation. In conclusion, several dietary lectins can trigger human basophils to release IL-4 and IL-13. Since lectins can enter the circulation after oral uptake, they might play a role in inducing the so-called early IL-4 required to switch the immune response towards a Th2 response and type I allergy.

Basophils↗

PubMed1999

Expression of tumour necrosis factor receptors (CD120a and CD120b) on bronchoalveolar cells.

It is generally accepted that physiological modulators for tumour necrosis factor (TNF) are present in a variety of body fluids including serum. Among these modulators are soluble TNF receptors (TNF-R) that are cleaved from the extracellular domain of the TNF-Rs. Two receptors of different structures with molecular weights of 55 kDa (CD120a) and 75 kDa (CD120b) are known to be expressed on monocytes, lymphocytes, granulocytes and other cells of peripheral blood. The aim of our study was to determine the expression of CD120a and CD120b on bronchoalveolar lavage cells (BAL cells). BAL cells of 14 patients with different pulmonary disorders were stained with anti-CD120a and anti-CD120b monoclonal antibodies and were differentiated by FACS analysis. Both TNF-Rs are expressed on monocytes, macrophages, lymphocytes and granulocytes of the BAL. Although the relation of CD120a to CD120b is individual for a given cell type and an individual patient, strict correlations between both receptors were observed for BAL monocytes and alveolar macrophages. CD120a are expressed on 29.7% of alveolar macrophages; similar data were obtained for CD120b. 24.3% of the BAL monocytes were positive for CD120a and 25.5% for CD120b. 4.1% of the BAL lymphocytes were positive for CD120a whereas the percentage of CD120b positive BAL lymphocytes was approximately six times greater. Analysis of BAL granulocytes revealed 21.2% cells positive for CD120a and 11.6% for CD120b. In contrast to the BAL cells named above there was no positive correlation between CD120a and CD120b expression on BAL lymphocytes and granulocytes. We were able to show that TNF-Rs of BAL cells, like those of blood cells, are shedded in vitro after incubation with or without lipopolysaccharide (LPS), detected as TNFalpha-inhibitor activity in cell culture supernatant. In conclusion, BAL cells express and shed TNF-Rs, as is known for cells of other body compartments.

Antibodies, Monoclonal↗

PubMed1999

Polymorphisms at position -308 in the promoter region of the TNF-alpha and in the first intron of the TNF-beta genes and spontaneous and lipopolysaccharide-induced TNF-alpha release in sarcoidosis.

TNF-alpha is a potent pro-inflammatory cytokine. Previous studies have proved that biallelic polymorphisms in the TNF-alpha (-308, TNFA) and TNF-beta genes (intron 1, TNFB) influence TNF-alpha production. In sarcoidosis, a chronic granulomatous disease, as a result of an unknown in vivo activation bronchoalveolar lavage (BAL) cells release high amounts of TNF-alpha, spontaneously and after in vitro stimulation. Thus, sarcoidosis could serve as a model to test the in vivo effect of TNF gene polymorphisms. We determined the TNFA and TNFB polymorphisms of 44 patients with sarcoidosis and found the following allele frequencies: 0.80, 0.20, 0.38 and 0.62 for TNFA1, TNFA2, TNFB1 and TNFB2, respectively. To examine the in vivo effect of the named polymorphisms on the TNF-alpha production, the spontaneous and LPS-induced TNF-alpha release of BAL cells and peripheral blood mononuclear cells were also determined in patients with sarcoidosis. Statistical analysis did not reveal any significant difference between sarcoidosis patients with different genotypes. The results show that TNFA and TNFB polymorphisms do not determine the level of TNF-alpha release of mononuclear cells activated during the course of sarcoid inflammation.

Alleles↗

PubMed1999

Pharmacological modulation of the IFNgamma-induced accessory function of alveolar macrophages and peripheral blood monocytes.

OBJECTIVE AND DESIGN: Although alveolar macrophages (AM) are poor accessory cells, alveolar macrophages of patients with sarcoidosis or tuberculosis show an elevated accessory function indicating that the accessory function (AF) of AM can be upregulated. MATERIALS AND METHODS: We examined whether the AF of AM and peripheral blood monocytes (PBM) can be increased by interferon-gamma (IFNgamma) and whether immunomodulating drugs like cyclosporine A, cyclophosphamide, dexamethasone, and ambroxol are able to modulate the accessory function and the expression of accessory molecules. RESULTS: IFNgamma increased the AF of AM and PBM up to 309 +/- 122% and 152 +/- 25%, respectively (p < 0.02, unstimulated control = 100%, in all cases). In alveolar macrophages this increase is most efficiently prevented by cyclosporine A (31 +/- 13%), followed by cyclophosphamide (64 +/- 20%) and dexamethasone (66 +/- 20%). In monocytes the IFNgamma-induced increase in accessory function is prevented only by cyclosporine A (17 +/- 7%) and dexamethasone (59 +/- 9%). Cyclosporine A was also the most effective drug downregulating the expression of accessory molecules (CD54, CD58, CD80 and CD86). CONCLUSIONS: In summary, the accessory function of alveolar macrophages and monocytes is upregulated by IFNgamma and can be controled by immunomodulating drugs.

Aged↗

PubMed1999

Analysis of differentially regulated mRNAs in monocytic cells induced by in vitro stimulation.

Macrophages are known to be effector cells in several granulomatous disorders. However, little is known about granuloma-associated up- or downregulation of genes in these cells. Differential display reverse transcription polymerase chain reaction (DDRT-PCR) is an attractive method for the detection of differentially expressed genes. Although this method entails a number of drawbacks, its application to rare and limited amounts of clinical samples is still convenient. In this study, we introduce a screening procedure for detecting differentially regulated sequence tags in samples of patients suffering from granulomatous diseases. We applied DDRT-PCR in a multiple and complex comparison of expressed sequence tags in response to various granuloma-associated stimuli. The histiocytic cell line U937 was used as a model. The cells had been stimulated with granuloma-associated agents such as Mycobacterium tuberculosis, BeSO4, lipopolysaccharide, or HgS and unspecific stimuli such as phorbol myristate acetate, phytohemagglutinin, Zymosan, and Latex. Comparative analysis of 2237 sequence tags obtained from 55 primer combinations revealed 22.4% differentially amplified PCR products. Notably, only 8.0% of the differentially expressed sequence tags showed an association restricted to in vitro cultivation in the presence of M. tuberculosis, lipopolysaccharide, BeSO4, and/or HgS, while 1.0-1.9% of the tags were altered exclusively as a consequence of stimulation with one of the granuloma-associated agents. Our data provide evidence that this strategy may function as a preselection for appropriate primer combinations to discover sequence tags which could be specifically associated with granulomatous disorders. This approach could shorten laborious screening, save consumption of valuable and rare samples, and could reduce the number of false-positive results.

Cell Line↗

PubMed1999

Monitoring allergen immunotherapy of pollen-allergic patients: the ratio of allergen-specific IgG4 to IgG1 correlates with clinical outcome.

BACKGROUND: Although allergen immunotherapy has been established as a treatment of type I allergy back in 1911, until now the underlying mechanisms have not been fully understood, nor are there any parameters which would allow one to monitor an ongoing treatment or to assess therapeutic success in the meantime. OBJECTIVE: We wanted to define allergen-specific parameters that change due to treatment in correlation with the clinical outcome. METHODS: We conducted a controlled study with grass pollen-allergic children and compared allergen-specific antibody titres before and 1 year after the onset of immunotherapy in contrast with untreated allergic and healthy children. Two recombinant forms of the major allergen group V of Phleum pratense (Phl p 5) served as model allergens. RESULTS: No change in IgE levels and no significant reduction of skin prick test (SPT) reactivity were seen. On the other hand, a significant reduction of symptom scores in the treated group and a significant rise in allergen-specific IgG1, IgG2 and IgG4 due to the treatment could be observed, but in neither case could we establish a correlation between the increasing amounts of the single antibody classes and the reduction of symptom scores. But most interestingly, when comparing the ratio of IgG4 to IgG1 with the symptom scores, we found significant correlations. Nevertheless, treated allergic patients still differ considerably from healthy controls as nonatopics have hardly any measurable allergen-specific IgG antibodies and no IgE antibodies at all. CONCLUSION: The ratio of IgG4 to IgG1 can serve as a valuable parameter that allows us to assess the success of immunotherapy already 1 year after the onset. The increase of specific IgG1 in relation to IgG4 during treatment reflects a possible influence of this subclass on the induction of tolerance towards allergens.

Allergens↗

PubMed1999

Grass group I allergens (beta-expansins) are novel, papain-related proteinases.

Expansins are a family of proteins that catalyse long-term extension of isolated plant cell walls due to an as yet unknown biochemical mechanism. They are divided into two groups, the alpha-expansins and beta-expansins, the latter group consisting of grass group I allergens and their vegetative homologs. These grass group I allergens, to which more than 95% of patients allergic to grass pollen possess IgE antibodies, are highly immunologically crossreactive glycoproteins exclusively expressed in pollen of all grasses. Alignments of the amino-acid sequences of grass group I allergens derived from diverse grass species reveal up to 95% homology. It is therefore likely that these molecules share a similar biological function. The major grass group I allergen from timothy grass (Phleum pratense), Phl p 1, was chosen as a model glycoprotein and expressed in the methylotrophic yeast Pichia pastoris to obtain a post-translationally modified and functionally active allergen. The recombinant allergen exhibited proteolytic activity when assayed with various test systems and substrates, which was also subsequently demonstrated with the natural protein, nPhl p 1. These observations are confirmed by amino-acid alignments of Phl p 1 with three functionally important sequence motifs surrounding the active-site amino acids of the C1 (papain-like) family of cysteine proteinases. Moreover, the significantly homologous alpha-expansins mostly share the functionally important C1 sequence motifs. This leads us to propose a C1 cysteine proteinase function for grass group I allergens, which may mediate plant cell wall growth and possibly contributes to the allergenicity of the molecule.

Allergens↗

PubMed1999

Early interleukin-4: its role in the switch towards a Th2 response and IgE-mediated allergy.

The etiology of IgE-mediated allergies is complex and, thus far, not completely understood. A common feature, however, is the overproduction of IgE-inducing cytokines, e.g. interleukin-4(IL-4), compared to IgE-antagonistic cytokines, such as interferon-gamma or IL-12. IgE-inducing cytokines are produced by T helper type 2 (Th2) cells. The differentiation of naive T cells towards the Th2 phenotype seems to be crucially dependent upon the particular cytokines present in the early stages of an immune response. Concerning the factors driving Th2 differentiation, the so-called 'early IL-4' seems to play an important role, although there is some controversy over the degree of its requirement and its cellular source. We have recently demonstrated that basophils might be such a source, since they rapidly release IL-4 upon antigen-specific or nonantigen-specific stimuli, such as certain lectins. This makes lectins interesting candidates for inducing a Th2 response and IgE-mediated allergy in unsensitized individuals.

Humans↗

PubMed1999

Selective cloning of peanut allergens, including profilin and 2S albumins, by phage display technology.

BACKGROUND: Peanut kernels contain many allergens able to elicit IgE-mediated type 1 allergic reactions in sensitized individuals. Sera from sensitized patients recognize variable patterns of IgE-binding proteins. The identification of the IgE-binding proteins of peanut extract would faciliate improvement of diagnostic and immunotherapeutic approaches as well as development of sensitive test systems for the detection of hidden peanut allergens present as additives in various industrial food products and the investigation of their stability during processing of food products. METHODS: We applied the pJuFo cloning system based on the phage surface display of functional cDNA expression products to clone cDNAs encoding peanut allergens. Sera (n = 40) of peanut-allergic individuals were selected according to case history, radioallergosorbent test and immunoblot analysis to demonstrate IgE binding towards the newly identified recombinant allergens. RESULTS: In addition to the known allergens Ara h 1 and Ara h 2 we were able to identify four allergens with estimated molecular weights of 36, 16, 14.5 and 14 kDa. Three of them formally termed Ara h 4, Ara h6 and Ara h 7 show significant sequence similarities to the family of seed storage proteins and the fourth (Ara h 5) corresponds to the well-known plant allergen profilin. Immunoblotting of the six expressed recombinant allergens with 40 patients sera shows 14 individual recognition patterns and the following frequency of specific IgE binding: Ara h 1 was recognized by 65%, Ara h 2 by 85%, Ara h 4 by 53%, Ara h 5 by 13%, Ara h 6 by 38% and Ara h 7 by 43% of the selected sera. CONCLUSIONS: All of the selected peanut-positive sera can detect at least one of the six identified recombinant allergens which can be used to establish individual patients' reactivity profiles. A comparison of these profiles with the clinical data will possibly allow a further insight into the relationship between clinical severity of the symptoms and specific IgE levels towards the six peanut allergens.

2S Albumins, Plant↗