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PubMed2001

Induction of oral tolerance to Japanese cedar pollen.

Oral tolerance is thought to play a role in preventing allergic responses and immune-mediated diseases. An improved mouse model of the oral tolerance to Japanese cedar pollen (JCP) as antigen was developed in order to detect induction of the tolerance, and the immunological characteristics of this model were also elucidated. Oral tolerance was induced by C3H/ HeN mice given an oral administration of 10 mg JCP 7 days before immunization with an i.p. injection of 0.1 mg JCP in complete Freunds adjuvant (CFA). The effects of oral JCP on systemic immunity were assessed by enzyme-linked immunosorbent assay (ELISA) of immunoglobulin (Ig) levels in serum collected on day 7 or 14 after immunization. Oral tolerance to JCP was adequately induced on day 7 after immunization and was more effective in C3H/HeN mice than in BALB/c mice. The tolerance was primarily concerned with the decreased serum levels of antigen-specific IgG. In these mice, oral administration of JCP also suppressed various immune responses to the antigen including delayed-type hypersensitivity (DTH), total IgE level and anti-JCP IgG1 level. The suppression of these immune responses by the oral antigen was associated with a significant reduction in interleukin-4 (IL-4) production. These findings therefore indicate that this C3H/HeN mice model has potential use in detecting the induction of oral tolerance by JCP, and suggest that this tolerance model may be effective in the treatment and prevention of allergic responses caused by the antigen.

Administration, Oral↗
PubMed1998

Interactive computer-assisted position acquisition procedure designed for the analysis of organelle movement in pollen tubes.

An interactive computer-assisted video microscopy method has been developed for the acquisition of extensive data on the sequential positions of pollen tube organelles, which cannot be automatically tracked using geometric or motion patterns. The method consists of video microscopy, analog and digital contrast enhancement, digital time-lapsing of the images, and interactive selection of positions in a coordinate system corresponding to the cell shape and real size. Data on 15,000 positions acquired with this method have been used to make quantitative analyses of the movement patterns of the organelles. From these analyses and the reconstruction of 900 trajectories, it appears that movements are random in the tip of the pollen tube but become more directed in distal regions of the cell, indicating an increase in axial arrangement of the actin filaments. (All custom-made software is available from the authors on request.)

Cell Movement↗
PubMed2003

[A case of tomato juice-induced oral allergy syndrome in which dyspnea onset occurred during the season of Japanese cedar pollen dispersion].

A 42-year-old-man with a history of Japanese cedar pollinosis repeatedly visited the emergency clinic due to dyspnea during the season of Japanese cedar pollen dispersion. Before each onset of this symptom, he had always drunk tomato juice. Swelling of the oral and nasal mucosa, and congestion of the bulbar conjuctiva was observed. No audible wheezing was present. His pulmonary function test results were normal (FEV 1.0 = 4.02 L, %FEV 1.0-124%, negative reversible test). The CAP RAST scores were 4 for tomatoes and 3 for Japanese cedar pollen. A result was obtained in a challenge test using tomato juice. Since tomato juice was involved in the development of the symptoms, a diagnosis of oral allergy syndrome induced by tomato juice was made. When tomato juice consumption was avoided, no symptoms developed. A common antigenicity was found between tomatoes and Japanese cedar pollen. This may be associated with the development of this allergy during the dispersion season of Japanese cedar pollen. The dyspnea may have reflected a feeling of pharyngeal narrowing which is a symptom of oral allergy syndrome. The possibility of oral allergy syndrome as the chief complaint should be considered also in patients with dyspnea. This is the first reported case of oral allergy syndrome induced by tomato juice.

Adult↗
PubMed2000

Spatial and temporal patterns of GUS expression directed by 5' regions of the Arabidopsis thaliana farnesyl diphosphate synthase genes FPS1 and FPS2.

Farnesyl diphosphate synthase (FPS), the enzyme that catalyses the synthesis of farnesyl diphosphate (FPP) from isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), is considered a regulatory enzyme of plant isoprenoid biosynthesis. The promoter regions of the FPS1 and FPS2 genes controlling the expression of isoforms FPS1S and FPS2, respectively, were fused to the beta-glucuronidase (GUS) reporter gene and introduced into Arabidopsis thaliana plants. The FPS1S:GUS gene is widely expressed in all plant tissues throughout development, thus supporting a role for FPS1S in the synthesis of isoprenoids serving basic plant cell functions. In contrast, the FPS2:GUS gene shows a pattern of expression restricted to specific organs at particular stages of development. The highest levels of GUS activity are detected in flowers, especially in pollen grains, from the early stages of flower development. After pollination, much lower levels of GUS activity are detected in the rest of floral organs, with the exception of the ovary valves, which remain unstained throughout flower development. GUS activity is also detected in developing and mature seeds. In roots, GUS expression is primarily detected at sites of lateral root initiation and in junctions between primary and secondary roots. No GUS activity is detected in root apical meristems. GUS expression is also observed in junctions between primary and secondary stems. Overall, the pattern of expression of FPS2:GUS suggests a role for FPS2 in the synthesis of particular isoprenoids with specialized functions. Functional FPS2 gene promoter deletion analysis in transfected protoplasts and transgenic A. thaliana plants indicate that all the cis-acting elements required to establish the full pattern of expression of the FPS2 gene are contained in a short region extending from positions -111 to +65. The potential regulatory role of specific sequences within this region is discussed.

Alkyl and Aryl Transferases↗
PubMed1998

PCP-A1, a defensin-like Brassica pollen coat protein that binds the S locus glycoprotein, is the product of gametophytic gene expression.

Self-incompatibility (SI) in Brassica species is controlled by a single polymorphic locus (S) with multiple specificities. Two stigmatically expressed genes that have been cloned from this region encode the S locus glycoprotein (SLG) and S receptor kinase (SRK). Both appear to be essential for the operation of SI. It is believed that rejection of incompatible pollen grains is effected by recognition events between an as yet unidentified S locus-encoded pollen coating-borne protein and the SLG/SRK. We previously identified a small pollen coat protein PCP7 (renamed here PCP-A1, for pollen coat protein, class A, 1) that binds with high affinity to SLGs irrespective of S genotype. Here, we report the cloning of PCP-A1 from Brassica oleracea and demonstrate that it is unlinked to the S locus. In situ localization of PCP-A1 transcripts revealed that they accumulate specifically in pollen at the late binucleate/trinucleate stage of development rather than in the tapetum, which previously was taken to be the principal source of the pollen coat. PCP-A1 is characterized by the presence of a structurally important motif consisting of eight cysteine residues shared by the plant defensins. Based on the presence of this motif and other data, homology modeling has been used to produce a putative structure for PCP-A1. Protein-protein interaction analyses demonstrate that SLG exists in monomeric and dimeric forms, both of which bind PCP-A1. Evidence is also presented for the existence of putative membrane-associated PCP-A1 binding proteins in stigmatic tissue.

Amino Acid Sequence↗
PubMed1988

Pollen count, symptom and medicine score in birch pollinosis. A mathematical approach.

This study investigates the correlation between the daily birch pollen counts, hay fever symptoms and medicine scores. Fifteen birch pollinosis patients were studied during two consecutive birch pollen seasons. All had a positive history for birch hay fever and a positive skin prick test, nasal provocation test and/or conjunctival provocation test to birch pollen. The patients recorded daily symptom and medicine scores during February through May for two seasons. According to nasal/conjunctival sensitivity and medicine consumption the group was divided into three groups: very sensitive, sensitive, and fairly sensitive. The mathematical calculations were based only on the results from the two most sensitive groups. The relationship between symptom scores and medicine scores as a function of the pollen load was nonlinear. A mathematical model was calculated. It was found that simply adding symptom scores and medicine scores to a total symptom/medication score was not meaningful as a basis for a quantitative analysis. It was further shown that the response caused by a given pollen load decays exponentially with time and that this decay had a characteristic half-life period of about 1-2 days indicating a long-lasting effect, i.e. contribution of the late allergic reaction to symptoms. Both groups showed the development of increased medicine intake during the season for a constant pollen load. This indicates the development of a higher sensitivity to birch pollen during the season. The overall response was divided into characteristic levels based on dose-response relationships, and pollen concentration intervals for forecasting purposes are suggested.

Adolescent↗
PubMed2006

Isolation and characterisation of two wheat beta-expansin genes expressed during male gametophyte development.

Two novel beta-expansin genes, TaEXPB1 and TaEXPB2, were isolated from wheat microspores by suppression subtractive hybridisation. Northern blot and reverse transcription PCR analyses showed that the expression of both genes was restricted to early stages of male gametophyte development (from microspores to immature pollen). A homology search showed high similarity of the newly discovered genes to generative beta-expansins in grass pollen (group 1 pollen allergens). Southern hybridisation revealed that the isolated genes belong to a distinct group within the subfamily of beta-expansin genes in the wheat genome. A comparison of full-length cDNAs with the corresponding genomic sequences showed that there are two introns in the TaEXPB1 gene, whereas TaEXPB2 has three introns. Both genes were predicted to encode highly similar basic proteins (pI 9.0) with molecular masses of approximately 29 kDa consisting of a signal peptide, catalytic, and polysaccharide binding domains, which include conserved cysteines and tryptophans and motifs characteristic for beta-expansins.

Amino Acid Sequence↗
PubMed1993

Analysis of a desiccation and ABA-responsive promoter isolated from the resurrection plant Craterostigma plantagineum.

The resurrection plant Craterostigma plantagineum can recover from severe desiccation within 24 h of contact with water, and it is used as a model system to analyse desiccation tolerance in higher plants. During drying or ABA treatment a specific set of transcripts accumulates rapidly in leaves and other tissues. In order to study transcriptional mechanisms of stress-induced gene expression one gene (CDeT27-45) was selected for promoter analysis. Chimeric gene fusions were constructed of the CDeT27-45 promoter and beta-glucuronidase or luciferase. These constructs were tested in a homologous transient expression system which allowed the identification of promoter elements conferring ABA inducibility. By introducing the chimeric gene fusions into tobacco via Agrobacterium-mediated transformation we found that the promoter activity is under strict tissue-specific and developmental control. In tobacco the promoter was only active in developing embryos and in mature pollen grains-two tissues which are naturally desiccation tolerant in tobacco. The specific temporal expression pattern was attributed to particular 5' upstream sequences. The promoter analysis presented here should allow the separation of important regulatory components as a first step in dissecting events in the signal transduction chain.

Abscisic Acid↗
PubMed1997

Identification, subcellular localization, and developmental studies of oleosins in the anther of Brassica napus.

mRNAs encoding putative oleosins have been detected in the tapetum of developing anthers in Brassica and Arabidopsis, but the authentic proteins have not been previously documented. Antibodies against a synthetic 15-residue polypeptide that represents a portion of the putative tapetum oleosins encoded by two cloned Brassica napus genes were raised. Using these antibodies for immunoblotting after SDS-PAGE of the sporophytic extracts of B. napus developing anthers, two oleosins of approximately 48 and 45 kDa were detected. These two oleosins were judged to be the putative oleosins encoded by cloned Brassica genes because of their identical N-terminal sequences. The two oleosins were present in the anthers only during the developmental stage when the tapetum cells were packed with organelles. A fraction of lowdensity organelles was isolated from the developing anthers by flotation centrifugation. The fraction contained plastoglobule-filled plastids and lipid-containing particles. The structures of these two isolated organelles were similar to those in situ in the tapetum cells. Of subcellular fractions of the anther homogenate, the two oleosins were present exclusively in the low-density organelle fraction. They were absent in the surface fractions of the developing microspores and the mature pollen, although fragmented oleosin molecules were earlier reported to be present on the pollen. By immunocytochemistry, immunogold particles were found largely on the periphery of the plastoglobuli inside the plastids in the tapetum cells. The antibodies also detected oleosins on the surface of storage oil bodies inside the maturing microspores. Apparently, the gametophytic microspore oil-body oleosins share common epitopes at the generally non-conserved C-terminal domain with the sporophytic tapetum oleosins.

Amino Acid Sequence↗
PubMed1997

Pollination-Induced Ethylene in Carnation (Role of Stylar Ethylene in Corolla Senescence).

In carnation (Dianthus caryophyllus L. cv White Sim) cell to cell communication between the pollen and pistil induces ovary development and corolla senescence. The production of elevated ethylene by the style is the first measurable postpollination response. This is followed by a wave of ethylene production from the other floral organs. To investigate the regulation of ethylene biosynthesis in pollinated flowers we measured ethylene production and the expression of 1-aminocyclopropane-1-carboxylate synthase and 1-aminocyclopropane-1-carboxylate oxidase transcripts in individual floral organs after pollination. Ethylene production by pollinated styles can be defined temporally by three distinct peaks. By pollinating a single style from a multistyle gynoecium, it was determined that the unpollinated style produces ethylene that corresponds to the first and third peaks observed from a pollinated style. Inhibition of ethylene action in the pollinated style by diazocyclopentadiene treatment prevented both pollination-induced corolla senescence and ethylene production from the ovaries and petals. Treatment with diazocyclopentadiene decreased stylar ethylene production during the second peak and completely inhibited the third peak of ethylene in both pollinated and unpollinated styles. This later auto-catalytic ethylene in styles is likely responsible for pollination-induced corolla senescence and ovary development.

Journal Article↗
PubMed1995

A potato Sus3 sucrose synthase gene contains a context-dependent 3' element and a leader intron with both positive and negative tissue-specific effects.

To examine which sequences are involved in regulating the potato sucrose synthase gene Sus3-65, we examined a series of deletion and substitution constructs in transgenic potato and tobacco plants. In a construct containing 3.9 kb of 5' flanking region, substitution of the native 3' sequence with the nopaline synthase 3' sequence and deletion of the leader intron did not significantly affect expression in vegetative tissues. However, in a construct containing only 320 bp of 5' flanking region, these changes had marked effects. Replacing the native 3' sequences with nopaline synthase 3' sequences caused a six- to 20-fold increase in expression in vascular tissue, and removing the leader intron almost completely abolished expression in potato plants. Surprisingly, removal of the leader intron from either the full-length construct or a construct containing only 320 bp of 5' flanking sequence reduced expression in vascular tissue of tobacco anthers at later stages of development but increased expression in pollen by more than 100-fold.

Base Sequence↗
PubMedDate not supplied

[The role of H+/- ATPase and alternative oxidase in the regulation of intracellular pH at the different stages of development of the tobacco male gametophyte].

In order to determine the role of the plasma membrane H(+)-ATPase and alternative oxidase (alternative pathway of respiration) in the regulation of intracellular pH during development of the tobacco male gametophyte, we studied the changes in pH due to the inhibition of these enzymes by orthovadanate and benzhydroxamic acid, respectively. The inhibition of these enzymes decreased the intracellular pH at all three studied stages of the male gametophyte development: middle and late binuclear pollen grains and activated mature pollen grain. The data obtained suggest that H(+)-ATPase and alternative oxidase are involved in the regulation of intracellular pH of the pollen grain during its differentiation and activation that precede germination. At the same time, during the recovery of intracellular pH after its acidification by propionic acid, it was found that other mechanisms, not related to the above mentioned, greatly contribute to the regulation of pH.

Cell Membrane↗
PubMed1991

Patterns of gene expression in developing anthers of Brassica napus.

The relationship between bud length, anther length and stage of anther development has been investigated in Brassica napus using a series of cytological markers that define steps in the process of male gametogenesis. It was determined that bud length is directly related to anther length and that anther or bud length is tightly linked to the stage of male gametogenesis within the anther. This simple correlation has enabled the construction of cDNA libraries representing transcripts expressed in defined stages of anther development, and the detailed examination of the developmental pattern of expression of anther RNAs. Two anther cDNA libraries were constructed, one from anthers of 1.2-1.8 mm long buds (sporogenesis library) and one from anthers of 1.8-4.0 mm long buds (microspore development library). A total of 19 independent cDNAs have been isolated by differential screening whose temporal expression patterns overlap and which together cover the stages of anther development from pre-meiotic microsporocytes to tri-nucleate pollen grains. The pattern of expression of each of these clones is unique and indicates that stages of anther development which cannot be easily distinguished by light microscopy can be recognised by virtue of the absence or presence of certain RNAs. Three cDNAs isolated from the sporogenesis library have been shown by in situ hybridisation to be tapetum-specific. In contrast, five clones isolated from the microspore development library are microspore-specific. These clones exhibit a pattern of expression different to those previously described in that their transcripts are absent in mature pollen grains. Thus these RNAs are probably required in microspore development rather than for the growth of the germinating pollen grain.

Blotting, Northern↗
PubMed2001

[Pollen morphology of bee plants in Changbai Mountain area].

OBJECTIVE: To develop and utilize the bee plants and bee products in Changbai Mountain area, the representative area of alpine plants in northeast China featuring abundant resources of bee plants. METHOD: The pollen of bee plants was observed and studied by LM and SEM. RESULT: The pollen is morphologically oblate, suboblate, spheroidal and prolate. The external sculpture is commonly reticulate, striate and echinulate. CONCLUSION: Plant pollen identification criteria have been furnished for the development of bee plant resources as well as the inspection of bee products in Changbai Mountain area.

Animals↗
PubMed2002

Combination vaccines for the treatment of grass pollen allergy consisting of genetically engineered hybrid molecules with increased immunogenicity.

Most of the 400 million grass pollen-allergic patients worldwide are co-sensitized to several unrelated grass pollen allergens. Based on frequent co-sensitization patterns determined in 200 grass pollen-allergic patients, three recombinant hybrid molecules were developed by polymerase chain reaction-based mending of cDNAs coding for the major timothy grass pollen allergens (Phl p 1, Phl p 2, Phl p 5, Phl p 6) for vaccination against grass pollen allergy. The hybrids rP2-P6, rP6-P2, and rP5-P1 contained most of the epitopes of natural grass pollen extract and induced stronger lymphoproliferative responses in cultured mononuclear cells of grass pollen-allergic patients than did equimolar mixtures of the individual allergens. Immunization of mice with the hybrids yielded higher antibody titers than did immunization with the individual allergen components or grass pollen extract, which suggests that the individual components of the hybrids can serve as molecular scaffolds for each other to enhance their immunogenicity. Antibodies induced with the hybrids in mice inhibited the binding of grass pollen-allergic patients' immunoglobulin E to each of the individual allergens and grass pollen extract and may thus represent protective antibodies. The principle of increasing the immunogenicity of antigens by engineering hybrids thereof may be applied not only for the treatment of polysensitized allergic patients but also for general vaccine development.

Allergens↗
PubMed2005

Mode of pollen-tube growth in Pistils of Myrica rubra (Myricaceae): a comparison with related families.

BACKGROUND AND AIMS: It is generally known that fertilization is delayed for more than a few weeks after pollination in Fagales. Recent studies showed that, during that period, pollen tubes grew in pistils in close association with the development of the ovule in a five-step process in Casuarina (Casuarinaceae) and a four-step process in Alnus (Betulaceae). The number of pollen tubes was reduced from many to one, a fact suggesting that delayed fertilization plays a role for gametophyte selection. Myrica (Myricaceae) also shows delayed fertilization for >2 weeks after pollination, but nothing is known of how pollen tubes grow in the pistil during that period. METHODS: Pollen-tube growth and the development of the ovule in pistils was investigated by fluorescent and scanning electron microscopy and analysis of microtome sections of the pistils. KEY RESULTS: Developmental study of the pollen-tube growth in the pistil of M. rubra showed that the tip of the pollen tube was branched or lay in a zigzag pattern in the upper space of the ovarian locule or near the tip of the integument, and subsequently was swollen on the nucellar surface. Such morphological changes indicate that the pollen-tube growth was temporarily arrested before fertilization. The pollen-tube growth in M. rubra can therefore be summarized as occurring in three steps: (1) from the stigma to the ovarian locule; (2) from the ovarian locule to the nucellar surface; and (3) from the nucellar surface to the embryo sac. CONCLUSION: Myrica differs from other families in that the pollen tubes arrest their growth on the nucellar surface, probably digesting nutrient from nucellar cells. There is little information on five other families of Fagales. An extensive study is needed to better understand the diversity and function of the mode of pollen-tube growth within the order.

Betulaceae↗
PubMedDate not supplied

Relationship of clinical and aerobiological pollen data in the north-west of Spain.

BACKGROUND: few studies report clinical and aerobiological pollen data in the north-west of Spain, a region similar to northern and central Europe. Moreover, it is difficult to obtain patients' collaboration in filling out symptom cards. The aim of this study was to establish a relationship between pollen types and clinical data obtained through questionnaire and telephone calls. PATIENTS AND METHODS: from January to December 2000, 24 patients aged 28 10.6 years and allergic to pollens were studied. The seasonal and hourly rhythm of symptoms and their intensity were obtained monthly by telephone calls. Atmospheric pollen was collected over the same period using a Hirst-type volumetric pollen sampler. RESULTS: the most important pollen types recorded were Poaceae, Betula, Parietaria and Plantago. Most patients (83 %) showed symptoms during March and in the period between May and July (99 %), which coincided with the greatest quantity of atmospheric pollen. Fifty-six percent of the patients complained of symptoms during the first hours of the morning, 63 % during the central hours of the day and 22 % at nightfall. In specific sensitizations, symptoms were more evident during the hours of maximum atmospheric levels of their taxa. CONCLUSIONS: the method employed in the present study to obtain information on patients' symptomatology (telephoning their homes once a month) proved useful and revealed a clear relationship between the presence of certain pollens in the atmosphere and the development of symptoms.

Adolescent↗
PubMedDate not supplied

Antigenic activity in monkey and human of purified low molecular weight fractions of Timothy pollen.

Small molecular weight fractions obtained from dialysis of crude Timothy pollen extract were shown to carry immunogenic activity in monkeys. Three fractions were sequentially purified through gel filtration with Siphadex G-10 and C-M cellulose 52. Monkeys immunized with these fractions produced almost exclusively skin-sensitizing antibodies which were shown to be of the IgE class and differing in antigenic specificity. The analysis of sugars and amino acids contained in two of these fractions showed large qualitative and quantitative differences. It is assumed that these fractions might represent oligomeric subunits of larger antigenic molecules. Challenge of patients allergic to Timothy pollen by means of skin tests and nasal provocation tests further confirms the absence of cross-antigenicity among the 3 active fractions. These results seem to indicate heterogenicity of IgE antibodies as developed following sensitization with crude Timothy pollen antigen.

Absorption↗