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Biomedical subjects

H Rumpold

Publications and source records attributed to H Rumpold.

At least 55 records · Page 3Linked to original sources

Detection of anti-neutrophil cytoplasmic antibodies after acute Plasmodium falciparum malaria.

Four of 30 patients with Plasmodium falciparum infection in Bangkok, Thailand, were positive for anti-neutrophil cytoplasmic antibodies by indirect immunofluorescence 1 month after antimalarial therapy. No myeloperoxidase, proteinase 3, lactoferrin, or elastase reactivity was found. Since no evidence of vasculitis was seen in these patients, anti-neutrophil cytoplasmic antibody production in malaria-infected susceptible patients probably represents a secondary response, indicating neutrophil activation.

Acute Disease↗

Serum levels of the carboxy-terminal cross-linked telopeptide of type I collagen and laminin are elevated in Graves' disease but not in toxic nodular goiter.

We determined serum levels of laminin, carboxy-terminal cross-linked telopeptide, and carboxy-terminal propeptide of type I collagen (ICTP and PICP) in 27 patients with Graves' disease (GD) and in 31 patients with toxic nodular goiter (TNG). Elevated levels of soluble laminin and ICTP were observed in patients with GD prior to treatment (mean +/- SD concentration 1444 +/- 404 and 8.6 +/- 3.5 ng/ml, respectively), compared to patients with TNG (476 +/- 103 and 4.2 +/- 1.5 ng/ml) and normal controls (492 +/- 112 and 3.1 +/- 1.3 ng/ml, n = 34). In contrast, serum PICP concentrations were not different between patients with GD or TNG and normal controls. In GD patients serum ICTP and laminin levels decreased during thiamazole treatment and normalized within 4 and 8 weeks of therapy. There was no correlation between serum ICTP and laminin levels and serum levels of thyroid hormones and/or autoantibodies, respectively. Serum ICTP and laminin could be markers for alterations of extracellular matrix during GD and release of matrix components in the circulation and/or reflect an impaired clearance.

Adult↗

IgE cross-reactivities against albumins in patients allergic to animals.

BACKGROUND: Type I allergic symptoms and severe asthma in particular are frequently caused by animal hair/dander proteins, among which albumins are possible cross-sensitizing allergenic components. METHODS: The significance and degree of IgE-cross-reactivities against various albumins were studied in a representative number (n = 200) of patients allergic to animals with hair/dander extracts, purified albumins from different animals, and a recombinant dog albumin fragment expressed in lysogenic Escherichia coli Y1089 and purified as a beta-galactosidase fusion protein. RESULTS: Despite a high degree of sequence homology among different albumins, a remarkable variability of IgE cross-reactivities was observed, indicating that some patients were sensitized preferentially against certain albumins. Most of the patients allergic to albumins, however, reacted to dog, cat, and horse albumin, which also bound a high percentage of albumin-specific IgE. CONCLUSION: The purified recombinant dog albumin fragment, representing 265 amino acids of the mature protein, bound IgE from all 15 patients allergic to albumin tested suggesting its potential usefulness for diagnosis and perhaps therapy.

Albumins↗

Molecular characterization of dog albumin as a cross-reactive allergen.

Indoor allergens comprise a group of allergenic proteins that are commonly derived from house dust mite and cat and dog dander. In addition to the two major dog allergens (molecular weights: 19 and 23 kd), dog albumin represents an important allergen for up to 35% of patients who are allergic to dogs. In IgE immunoblot inhibition studies and histamine release tests it has been demonstrated that patients who react to dog albumin exhibit IgE reactivity with purified albumins from cat, mouse, chicken, and rat. The proportion of dog-specific IgE directed against dog albumin was determined for patients allergic to dog albumin, and it ranges from 70% to 90%. By IgE immunoscreening of a lambda gt11 expression library from a dog salivary gland, we identified a number of reactive complementary DNA clones. All patients with IgE reactivity against natural dog albumin displayed IgE reactivity to the beta-galactosidase fusion protein encoded by clone 54c, which was therefore assumed to contain major IgE epitopes of dog albumin. The deduced amino acid sequence of clone 54c was compared with the Swiss-Prot library, and significant sequence homologies were found with albumins from different species (human: 82.6%, pig: 81.8%, cattle: 77.3%, sheep: 78.8%, mouse: 75.8%, and rat: 76.2%). Several other IgE-positive clones hybridized with oligonucleotides that were prepared according to this sequence. Partial complementary DNA coding for dog albumin fragments may be considered a useful tool for further characterization of major IgE epitopes of dog albumin.

Allergens↗

cDNA cloning of a major allergen from timothy grass (Phleum pratense) pollen; characterization of the recombinant Phl pV allergen.

We isolated a cDNA encoding a major grass pollen allergen from a timothy grass (Phleum pratense) pollen expression cDNA library using allergic patients' IgE. The complete cDNA encoded an allergen that binds IgE from about 80% of grass pollen-allergic patients. Significant sequence homology was found to other major grass pollen allergens from Kentucky bluegrass (Poa pratense) as well as from rye grass (Lolium perenne) which originally were believed to form different identities. Using different monoclonal and polyclonal antibodies raised against group V allergens we identified the recombinant protein as a group V allergen from timothy grass, Phl p V. In IgE-binding studies it is demonstrated that the rPhl p V allergen can be used to block binding of patients' IgE to natural group V isoallergens on two-dimensional immunoblots. IgE inhibition experiments show that up to 60% of grass pollenspecific IgE can be preadsorbed with the rPhl p V allergen from patients sera. The purified rPhl p V induced specific histamine release of blood basophils from grass pollen-allergic patients. This emphasizes the usefulness of the rPhl p V for diagnostic and therapeutic purposes and corroborates the view that specific diagnosis and therapy of type l allergy could be performed with a limited panel of relevant recombinant allergens.

Amino Acid Sequence↗

Four recombinant isoforms of Cor a I, the major allergen of hazel pollen, show different IgE-binding properties.

Previous studies showed that pollens from trees of the order Fagales (e.g. birch, alder, hazel and hornbeam) all contain one major allergen. These proteins are cross-reactive between these tree species, and approximately 95% of tree-pollen-allergic patients display IgE binding to these allergens. Using the reported N-terminal amino acid sequence of the hazel pollen allergen Cor a I, it was possible to amplify Cor-a-I cDNA by use of the polymerase chain reaction. Four clones with cDNA inserts were isolated. All four clones contained an open reading frame of 477 nucleotides (159 amino acids) but differed in length of their 3'-non-coding regions. Within the overlapping regions, the nucleotide sequence of the 3'-non-coding regions of the four clones were nearly identical. The open reading frames coded for different isoforms of the major hazel pollen allergen, Cor a I. The clones were designated Cor a I/5, 6, 11 and 16, respectively. Comparison of the deduced amino acid sequences of these Cor a I isoforms revealed identities of 96-99%. The sequence identities between the Cor a I isoforms and Bet v I, the major birch pollen allergen, were 71-73% (80.5-83% similarity). Comparing amino acid sequences of Cor a I isoforms with the published sequences of Aln g I, the major allergen from alder, and Car b I and isoforms, the major allergen from hornbeam, 75.5-76.7% identity (83.6-85% similarity) and 83.6-89.9% sequence identity (89.3-95% similarity), respectively, was found. The four Cor a I cDNAs were subcloned into plasmid pKK223-3 and expressed in Escherichia coli as non-fusion proteins; their capacity to bind serum IgE from tree-pollen-allergic patients was investigated. The four cloned isoforms showed an apparent molecular mass of 17 kDa in SDS/PAGE, identical to the natural, pollen-derived Cor a I. IgE antibodies from tree-pollen-allergic patients reacted with all four recombinant isoforms. However, we noted marked differences in the IgE-binding patterns of the distinct isoforms. Furthermore, Cor a I/11 was the only isoform recognized by the anti-(Bet v I) mAb, BIP 1. Our results demonstrate that Cor a I isoforms display different antigenic and allergenic properties, very likely due to few but significant changes in their amino acid sequences. These findings have implications for the development of reagents for diagnosis and immunotherapy of type I allergies.

Allergens↗

Characterisation of dog allergens by means of immunoblotting.

Sera from 75 patients with clinical type I allergy against dogs were investigated by means of immunoblotting using extracts prepared from dog hair/dander (CAN XI D) and saliva. In addition, selected sera were tested on extracts made of hair, skin, salivary glands (parotis and submandibularis), serum and liver. A 69-kD IgE-binding protein was identified in all extracts tested with an incidence of approximately 40% and shown to be dog albumin by means of inhibition experiments. In 96% of patients' sera IgE antibodies reactive with a 19-kD and/or a 23-kD protein of the hair/dander extract (CAN XI D) were observed. IgE binding to a 23-kD band was also detected in the hair and saliva extracts, but not in skin, salivary gland, serum and liver extracts. A 19-kD IgE-binding protein was strongly expressed in skin and to a lesser degree in saliva, but not in hair, serum and liver. Preincubation of patients sera with the hair extract and subsequent probing with the hair/dander extract (CAN XI D) inhibited IgE binding to the 23 kD protein whereas preincubation with the skin extract abolished IgE binding to the 19-kD protein. Using the hair/dander extract as inhibitor, IgE binding to the 19- and 23-kD proteins of saliva was abrogated. Thus it is concluded that the 23-kD protein is preferentially expressed in hair and saliva whereas the 19-kD protein is found in saliva and skin. Furthermore these two proteins are likely to represent immunologically independent major allergens.

Adolescent↗

Identification of common allergenic structures in hazel pollen and hazelnuts: a possible explanation for sensitivity to hazelnuts in patients allergic to tree pollen.

It is known that most patients with type I allergy to tree pollens also suffer from intolerance to nuts. To identify allergenic structures common to hazel pollen and hazelnuts, cross-reactivity of patients' IgE was investigated. With use of immunoblotting,.serum IgE from 25 patients displaying type I allergic reactions to tree pollens and intolerance to hazelnuts (group I) bound to the 17 kd major hazel pollen allergen Cor a I (100%) and to the 14 kd hazel pollen profilin (16%). IgE binding to proteins of comparable molecular weights in hazelnut extracts was found (18 kd and 14 kd), suggesting that proteins similar to Cor a I and hazel profilin might be also expressed in hazelnuts. In contrast, only four sera (22%) from 18 patients (group II) with tree pollen allergy but without any case history of nut hypersensitivity showed IgE binding to the 18 kd protein of hazelnut extract, and none of these sera exhibited IgE reactivity to the hazelnut profilin. To characterize the hazel pollen and hazelnut allergens, purified recombinant Bet v I (major birch pollen allergen) and purified recombinant Bet v II (birch profilin), respectively, were used for IgE-inhibition experiments. Binding of IgE from patients (with nut allergy) to the blotted hazelnut allergens could be blocked by preincubation of patients' sera with the recombinant proteins. Furthermore, the 18 kd protein of hazelnut extract was purified and induced specific release of histamine from basophils of a patient suffering nut hypersensitivity but not from a healthy control donor. A rabbit antibody raised against celery profilin identified the 14 kd proteins in hazel pollen and hazelnuts as profilin. Our experiments suggest a protein with IgE binding properties similar to the major allergens from pollens of hazel, Cor a I, and of birch, Bet v I, as predominant allergens in hazelnuts, and show that the plant pan-allergen profilin can be detected in both hazel pollen and hazelnut extracts.

Allergens↗

Distribution of allergens and allergen-coding mRNAs in various tissues of white birch.

The distribution of allergenic proteins was investigated in various tissues of white birch, Betula verrucosa (pollen, leaves and male inflorescences containing immature pollen). In addition, callus and suspension culture cells were investigated for expression of IgE-binding proteins. Furthermore, RNA was extracted from all these tissues and subjected to in vitro translation in a cell-free wheat germ system. Bet v I, the major birch pollen allergen, could be extracted easily from pollen, and in low amounts from callus and leaves. No Bet v I could be extracted from immature male inflorescences. Minor allergens were expressed in high concentrations in pollen and in low concentrations in immature male inflorescences. No minor allergens could be detected in callus and leaves. In contrast to these observations, RNA from all the tissues as well as from callus could be translated in vitro into Bet v I as well as into minor allergens, in particular birch profilin (Bet v II), an important minor allergen. These data suggest that IgE-binding proteins of B. verrucosa, especially Bet v I, under certain circumstances can readily be synthesized in tissues other than pollen. This concept is corroborated by the recent observation that Bet v I reveals high homology with disease resistance response gene products from other plants, suggesting a similar function of Bet v I for the birch.

Allergens↗

Identification of profilin as a novel pollen allergen; IgE autoreactivity in sensitized individuals.

A complementary DNA encoding a pollen allergen from white birch (Betula verrucosa) that was isolated from a pollen complementary DNA library with serum immunoglobulin E from a birch pollen-allergic individual revealed significant sequence homology to profilins. The recombinant protein showed high affinity to poly-L-proline. Immunoglobulin E antibodies from allergic individuals bound to natural and recombinant birch profilin and also to human profilin. In addition, birch and human profilin induced histamine release from blood basophils of profilin-allergic individuals, but not of individuals sensitized to other plant allergens. The structural similarity of conserved proteins might therefore be responsible for maintaining immunoglobulin E antibody titers in type I allergy.

Amino Acid Sequence↗

Common epitopes of birch pollen and apples--studies by western and northern blot.

Eighty-three sera from patients with birch-pollen allergy were investigated for IgE antibodies against apple allergens by means of immunoblotting. In immunoblots, 81 patients (97.6%) exhibited IgE directed against the major allergen of birch, Bet v I (17 kd), and these patients also demonstrated IgE binding to apple allergens in the molecular weight range 17 to 18 kd. Inhibition studies by preincubation of sera with birch-pollen extract led to complete blocking of IgE binding to this 17 to 18 kd protein, whereas preincubation with apple extract could not diminish IgE binding to Bet V I. Furthermore, a 17 kd protein in apple extract could be detected by immunoblotting with a Bet v I-specific monoclonal antibody. Northern blotting with a Bet v I cDNA clone as a probe revealed cross-hybridization of birch and apple allergen coding nucleic acids under conditions of high stringency, suggesting significant homology of the nucleic acid level. Our results support the concept that antigens in birch pollen and apples share allergenic epitopes leading to IgE cross-reactivities that may cause clinical manifestations when a special threshold level of specific IgE antibodies is reached.

Adolescent↗

Recombinant allergens for immunoblot diagnosis of tree-pollen allergy.

Diagnosis of type I allergy essentially depends on the availability of defined allergens, which can be provided by recombinant deoxyribonucleic acid (DNA) technology. We have previously isolated the c(complementary)DNAs encoding the major birch-pollen allergen, Bet v I, and another allergen with a molecular weight of 14 kd that was identified as birch profilin and designated Bet v II. These cDNAs were isolated from a lambda gt11 expression library by screening with the serum IgE from allergic patients. To obtain expression in Escherichia coli of recombinant allergens without additional fused polypeptides, both cDNAs were inserted into the plasmid pKK223-3. E. coli cells expressing Bet v I and birch profilin (Bet v II) were used for the preparation of recombinant proteins. These proteins were tested for their IgE-binding properties on immunoblots with sera from 100 different birch pollen-allergic patients. All patients' sera, which reacted with the natural allergens, Bet v I and Bet v II, demonstrated an identical IgE-binding pattern to recombinant birch-pollen allergens. Recombinant allergens may therefore be useful for the setup of diagnostic tests that allow the discrimination of different IgE-binding patterns as well as for patient-tailored immunotherapy.

Allergens↗

Homology of the major birch-pollen allergen, Bet v I, with the major pollen allergens of alder, hazel, and hornbeam at the nucleic acid level as determined by cross-hybridization.

To investigate the relationship of the major allergens of birch (Bet v I), alder (Aln g I), hazel (Cor a I), and hornbeam (Car b I) at the nucleic acid level, a cDNA clone coding for the complete Bet v I protein was used for Northern and Southern blot experiments. RNAs were isolated from pollen of birch (Betula verrucosa), alder (Alnus glutinosa), hazel (Corylus avellana), and hornbeam (Carpinus betulus). Hybridization was performed at different stringencies. At high stringency, comparable binding of the complete Bet v I cDNA probe to pollen RNAs from birch, alder, and hazel could be observed, indicating high homology of the mRNAs coding for these allergens. With the 3' and 5' half fragments of the Bet v I cDNA, both probes bound to transcripts of all four tree pollens, but most strongly to birch RNA. In Southern blots, distinct binding patterns of genomic DNA digests of birch, alder, hazel, and hornbeam were observed. Most bands were observed with birch DNA digests and less with alder, whereas in genomic DNA digests of hornbeam and hazel, only one band was observed. The result of these cross-hybridization experiments indicate a high homology at the nucleic acid level of the four major allergens of trees belonging to the order Fagales. The sequence similarity presented here further corroborates earlier observations of immunologic cross-reactivity at the protein level. Therefore, in the case of the major allergens of the Betulaceae, an extract with only one major allergen, preferentially Bet v I, instead of all four major allergens, should be sufficient for diagnostic and therapeutic purposes.

Allergens↗

The immunological relationship of epitopes on major tree pollen allergens.

The major allergens of birch (Bet v I), alder (Aln g I), hazel (Cor a I) and hornbeam (Car b I) were investigated by means of high-resolution two-dimensional electrophoresis combined with immunoblotting. Eleven sera derived from patients allergic to birch pollen as well as mouse monoclonal antibodies BIP 1 and BIP 4, raised against Bet v I, were used as probes. Human IgE antibodies detected 10 spots in birch (Mr 17 kDa, pI 4.9-5.9); four spots in alder (Mr 18.5 kDa, pI 4.7-5.3); four spots in hazel (Mr 17 kDa, pI 5.0-5.8); and 12 + 7 spots in hornbeam (Mr 16.5 kDa, pI 4.9-6.6 and Mr 18 kDa, pI 5.2-6.7), respectively, representing major allergens. Each patient tested reacted in a similar fashion with the spot cluster(s) of a certain allergen. BIP 1 detected the same spot clusters as patients' IgE. BIP 4 reacted with the 17-, 18.5- and 18-kDa spots of birch, alder and hornbeam, but did not react with the 17-kDa spots of hazel and the 16.5-kDa spots of hornbeam. In inhibition experiments with birch pollen extract as inhibitor, IgE binding to Bet v I, as well as to Aln g I, Cor a I and Car b I was abolished, thus suggesting that IgE binding to major tree pollen allergens is confined to shared epitopes. These findings indicate that it might be sufficient to use only Bet v I for diagnostic procedures as well as for immunotherapy in patients with tree pollen allergy.

Adolescent↗

Allergen profiles of dog hair and dander, body fluids and tissues as defined by immunoblotting.

The sera from 25 patients with clinical type I allergy against dogs were investigated by means of immunoblotting, using extracts of dog hair/dander, skin, hair, saliva, salivary gland, serum and liver. 96% of the patients' sera showed IgE antibodies reactive with 19- and 23-kilodalton (kDa) proteins in the hair/dander extract. The 23-kDa IgE-binding protein was preferentially detected in the hair extract and saliva but not in skin, salivary gland, serum and liver extracts. The 19-kDa band was strongly expressed in skin, but not in hair, serum and liver. Inhibition experiments using the 23-kDa containing extract prepared from hair and the 19-kDa containing extract prepared from skin revealed that these two proteins are likely to be immunologically independent allergens.

Adolescent↗

A low molecular weight allergen of white birch (Betula verrucosa) is highly homologous to human profilin.

Cloning of allergens has contributed substantially to the understanding of mechanisms in allergic diseases by providing information about the sequence and hence biological functions of allergens. The major birch pollen allergen, Bet v I [Breiteneder H, et al: EMBO J 1989;8:1935-1938] and the white-faced hornet venom allergen (antigen 5) [Si Yun Fang K, et al: Proc. Natl. Acad. Sc. USA 1988;85:895-899] were shown to be highly homologous to pathogenesis-related proteins of plants. In the case of the major allergen of house dust mite, Der p I, homology to proteases was demonstrated. Therefore, the proposed biological function of these IgE-binding proteins might be related to their allergenic potential. In this paper we tentatively identify a ubiquitous family of low molecular weight allergens as profilins. The identification is based on a sequence homology, (b) binding to poly(L-proline), and (c) immunological cross-reactivity. Recombinant birch profilin was purified to homogeneity and showed the same properties as natural profilins.

Allergens↗

Evaluation of immunotherapy-induced changes in specific IgE, IgG and IgG subclasses in birch pollen allergic patients by means of immunoblotting. Correlation with clinical response.

Sera from 27 birch pollen-allergic patients who had undergone hyposensitization treatment for 22-41 months were studied by immunoblotting before and after therapy, whereby the levels of IgE, IgG and IgG1-4 antibodies directed against the major allergen Bet v I and minor allergens of birch pollen were monitored. The clinical benefit of immunotherapy (IT) was evaluated using a symptom specific questionnaire. In patients with good clinical response (responders, n = 18), as defined by improvement of symptoms, anti-Bet v I IgE antibodies were found to decrease in 10/18 patients (55.5%), whereas in 6/18 (33.3%) no change and in two cases (11.2%) an increase of specific IgE was observed. In the group of patients with unsatisfactory clinical outcome (non-responders, n = 9), 3/9 patients (33.3%) showed a decrease, 3/9 (33.3%) no change and 3/9 (33.3%) an increase in levels of IgE antibodies directed against Bet v I. In the case of minor allergens, 5/18 responders (27.7%) and 8/9 non-responders (88.8%) showed specific IgE before IT. In the responder group, no increase of specific IgE could be observed after IT. In non-responders, however, an increase of IgE directed against minor allergens was seen in 3/9 patients (33.3%). In all patients, regardless of therapeutical success, IT-induced elevated levels of specific IgG, IgG1 and in particular IgG4 directed against Bet v I were found. Regarding minor allergens, a heterogeneous pattern of IgG responses without significant correlation to clinical benefit was observed. Our results indicate that changes in IgG reactivity patterns against Bet v I and minor allergens, as shown by the immunoblot technique, did not correlate with good or bad clinical outcome.

Adolescent↗

[What is the contribution of yeast genetics to tumor biology and tumor diagnosis?].

This short review article discusses methods and results of oncogene research in yeast. Current knowledge of the sequence, expression and biological function of ras-homologous genes of the yeast Saccharomyces cerevisiae is presented, as well as the implications of these findings for oncogene research in mammals. We review recent examples of highly conserved eukaryotic genes involved in growth control and mitosis control, including recent work from our own laboratories.

Cloning, Molecular↗