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PubMed2004

Increase of CC chemokine receptor 4-positive cells in the peripheral CD4 cells in dogs with atopic dermatitis or experimentally sensitized to Japanese cedar pollen.

BACKGROUND: Since dogs frequently develop allergic diseases, similar to those in humans, dogs represent a possible animal model for allergy in humans. In human atopic dermatitis (AD), CC chemokine receptor 4 (CCR4) has been shown to play an important role in the development of allergic inflammation of AD; however, the association between allergic reaction and CCR4 is not well understood in dogs. OBJECTIVE: To examine CCR4 expression in peripheral blood CD4+ cells in dogs that had AD and were experimentally sensitized with Japanese cedar pollen. MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from 17 dogs with AD. The proportion of CCR4+ cells in peripheral blood CD4+ cells (CCR4/CD4) was evaluated by flow cytometry and compared with that in 10 healthy dogs. Similarly, in dogs that were experimentally sensitized to Japanese cedar pollen antigen, the proportion of CCR4/CD4 was examined pre- and post-sensitization. RESULTS: The proportion of CCR4/CD4 in dogs with AD was 40.3+/-3.3%, which was significantly higher than that in normal dogs (23.6+/-4.3%) (P<0.01). In the experimentally sensitized dogs, the proportion of CCR4/CD4 was 25.4+/-2.6% at pre-sensitization and it was significantly increased (29.8+/-2.9%) at post-sensitization (P<0.01). CONCLUSION: The proportion of CCR4+ cells in peripheral blood CD4+ cells was measured in dogs with allergic conditions. The present findings indicate that CCR4+ cells may be involved in the pathogenesis of allergy in dogs as in humans.

Allergens↗
PubMed2005

Parentage versus two-generation analyses for estimating pollen-mediated gene flow in plant populations.

Assessment of contemporary pollen-mediated gene flow in plants is important for various aspects of plant population biology, genetic conservation and breeding. Here, through simulations we compare the two alternative approaches for measuring pollen-mediated gene flow: (i) the NEIGHBORHOOD model--a representative of parentage analyses, and (ii) the recently developed TWOGENER analysis of pollen pool structure. We investigate their properties in estimating the effective number of pollen parents (N(ep)) and the mean pollen dispersal distance (delta). We demonstrate that both methods provide very congruent estimates of N(ep) and delta, when the methods' assumptions considering the shape of pollen dispersal curve and the mating system follow those used in data simulations, although the NEIGHBORHOOD model exhibits generally lower variances of the estimates. The violations of the assumptions, especially increased selfing or long-distance pollen dispersal, affect the two methods to a different degree; however, they are still capable to provide comparable estimates of N(ep). The NEIGHBORHOOD model inherently allows to estimate both self-fertilization and outcrossing due to the long-distance pollen dispersal; however, the TWOGENER method is particularly sensitive to inflated selfing levels, which in turn may confound and suppress the effects of distant pollen movement. As a solution we demonstrate that in case of TWOGENER it is possible to extract the fraction of intraclass correlation that results from outcrossing only, which seems to be very relevant for measuring pollen-mediated gene flow. The two approaches differ in estimation precision and experimental efforts but they seem to be complementary depending on the main research focus and type of a population studied.

Computer Simulation↗
PubMed2003

AtMYB103 regulates tapetum and trichome development in Arabidopsis thaliana.

The AtMYB103 gene is a member of the R2R3 MYB gene family in Arabidopsis thaliana. Using the GUS reporter gene, AtMYB103 expression was found to be restricted to the tapetum of developing anthers. Employing RT-PCR and in situ hybridisation, we now show that AtMYB103 is also expressed in trichomes. GUS expression in trichomes was obtained by incorporating the coding and 3'-untranslated regions of AtMYB103 into the promoter-GUS constructs. Sense and antisense technologies were used to downregulate AtMYB103 expression. In transgenic lines with reduced AtMYB103 transcript levels, pollen, tapetum and trichome development were altered. The majority of the pollen grains were distorted in shape and had reduced or no cytoplasmic content. Tapetal degeneration occurred early, and large opaque bodies appeared in the tapetal cytoplasm. In transgenic plants, trichomes on cauline and rosette leaves produced additional branches. These overbranched trichomes contained more nuclear DNA than the wild-type trichomes. The results indicate that AtMYB103 is required for tapetal development and microsporogenesis, and negatively regulates trichome endoreduplication linked to the trichome branching.

Antisense Elements (Genetics)↗
PubMed1989

The relative risks of sensitivity to grass pollen, house dust mite and cat dander in the development of childhood asthma.

The associations between skin sensitivity to various common allergens and the development of childhood asthma were ascertained in a longitudinal study of a birth cohort of New Zealand children up to the age of 13 years. Of 714 children skin-tested, 45.8% were sensitive to at least one of 11 allergens, the most common responses being to rye grass pollen (32.5%), house dust mite (30.1%) and cat dander (13.3%). Allergen-specific relative risk analysis, controlled for the effect of sensitivity to other allergens, demonstrated that sensitivity to house dust mite and to cat dander were highly significant independent risk factors associated with the development of asthma (whether defined as recurrent typical respiratory symptoms, increased airway responsiveness, or the concurrent presence of both), whereas grass sensitivity was not a significant independent risk factor for asthma.

Animals↗
PubMed2002

Silencing of the tapetum-specific zinc finger gene TAZ1 causes premature degeneration of tapetum and pollen abortion in petunia.

TAZ1 (TAPETUM DEVELOPMENT ZINC FINGER PROTEIN1; renamed from PEThy; ZPT3-2) cDNA was first isolated as an anther-specific cDNA from petunia. Here, we report a functional characterization that includes analysis of spatial and temporal expression profiles and examination of anther phenotypes in TAZ1-silenced plants. TAZ1 showed a biphasic expression pattern. In the premeiotic phase, TAZ1 transcripts were found to accumulate in all cell types of the anther except the tapetum and gametophytic tissues, whereas the postmeiotic phase of anther development was characterized by expression exclusively in the tapetum. Silencing of TAZ1 by cosuppression resulted in aberrant development and precocious degeneration of the tapetum, followed by extensive microspore abortion that started soon after their release from pollen tetrads. A few pollen grains that survived showed reduced flavonol accumulation, defects in pollen wall formation, and poor germination rates. This study demonstrates an essential role for TAZ1 in the postmeiotic phase of tapetum development.

Cell Survival↗
PubMed1981

Selective suppression of antibody production with the aid of radiolabelled birch pollen allergen.

In accordance with the clonal selection theory we intended to prevent the development of artificially induced birch pollen allergy in rabbits with the aid of the radiolabelled pollen allergen (75-1000 microCi125 I-pollen/animal) intravenously administered prior to pollen sensitization. The birch pollen allergen, is accordance with Burnet's working hypothesis, reacts only with a genetically determining B cell subpopulation. The fixation of the radiolabelled birch pollen allergen to the receptors of the competent B cell clone causes the lesion of the latter. Compared with the control group, this group of rabbits showed an extensive suppression of anaphylactic reagin-like PCA-antibodies, and haemagglutinating antibodies in the blood as well as in nasal secretion. In addition, we tried to influence the already ongoing synthesis of the antibodies with the aid of subsequent intravenously administered radiolabelled birch pollen allergen (750-100 microCi 125 I-pollen/animal). An intensive suppression of the synthesis of antibodies could also be proved in this case. The simultaneous immunization of the control rabbits with birch pollen and egg albumin resulted in the production of antibodies against both antigens, as expected. The hot-labelled birch pollen antigen intravenously injected before or after immunization with egg albumin and birch pollen led selectively to suppression of anti-birch-pollen PCA antibodies. The synthesis of anti-egg albumin PCA antibodies was unaffected.

Allergens↗
PubMed2001

Rapid isolation, characterization, and glycan analysis of Cup a 1, the major allergen of Arizona cypress (Cupressus arizonica) pollen.

BACKGROUND: A rapid method for the purification of the major 43-kDa allergen of Cupressus arizonica pollen, Cup a 1, was developed. METHODS: The salient feature was a wash of the pollen in acidic buffer, followed by an extraction of the proteins and their purification by chromatography. Immunoblotting, ELISA, and lectin binding were tested on both the crude extract and the purified Cup a 1. Biochemical analyses were performed to assess the Cup a 1 isoelectric point, its partial amino-acid sequence, and its glycan composition. RESULTS: Immunochemical analysis of Cup a 1 confirmed that the allergenic reactivity is maintained after the purification process. Partial amino-acid sequencing indicated a high degree of homology between Cup a 1 and allergenic proteins from the Cupressaceae and Taxodiaceae families displaying a similar molecular mass. The purified protein shows one band with an isoelectric point of 5.2. Nineteen out of 33 sera (57%) from patients allergic to cypress demonstrated significant reactivity to purified Cup a 1. MALDI-TOF mass spectrometry indicated the presence of three N-linked oligosaccharide structures: GnGnXF(3) (i.e., a horseradish peroxidase-type oligosaccharide substituted with two nonreducing N-acetylglucosamine residues), GGnXF(3)/GnGXF(3) (i.e., GnGnXF with one nonreducing galactose residue), and (GF)GnXF(3)/Gn(GF)XF(3) (with a Lewisa epitope on one arm) in the molar ratio 67:8:23. CONCLUSION: The rapid purification process of Cup a 1 allowed some fine studies on its properties and structure, as well as the evaluation of its IgE reactivity in native conditions. The similarities of amino-acid sequences and some complex glycan stuctures could explain the high degree of cross-reactivity among the Cupressaceae and Taxodiaceae families.

Allergens↗
PubMed2006

Pollen specific immunotherapy is not a risk factor for de novo sensitization to cross-reacting allergens in monosensitized subjects.

BACKGROUND: Some studies have suggested that specific immunotherapy (SIT) may cause de novo sensitization to allergenic proteins to which patients were not previously allergic. This event might theoretically involve cross-reacting pollen allergens, such as profilin or polcalcins, posing a risk of SIT-induced polysensitization to pollens in patients who were originally monosensitized. OBJECTIVES: The aim of this study was to assess whether injection SIT with commercial pollen extract represents a risk factor for the de novo development of sensitization to different pollens in monosensitized patients. METHODS: The study involved 142 subjects diagnosed as being monosensitized to a single pollen: 64 patients who were administered a 3-year course of injection SIT and 78 controls. Subjects underwent control skin prick tests (SPT) with a series of 8 seasonal airborne allergens at least 3 years after the first visit. Patients with 5 or more new sensitivities on SPT were considered to be de novo polysensitized. RESULTS: At the end of the 3-year follow-up period, the proportion of polysensitized subjects was identical in previously monosensitized patients who underwent SIT and control individuals (11% and 10%, respectively). Individuals who were polysensitized were significantly younger than those who were not (mean age +/- SD, 21.6 +/- 11.0 years vs. 31.6 +/- 15.6 years; P < .05). CONCLUSION: SIT does not represent a risk factor for progression towards multiple pollen sensitization in monosensitized pollen-allergic patients.

Adolescent↗
PubMed1984

Antigen-induced eustachian tube obstruction: an intranasal provocative challenge test.

ETO and symptoms of AR have been demonstrated to develop after an intranasal provocative antigen-challenge test. To determine the antigen dose required to produce ETO, intranasal insufflations of increasing amounts of pollen (ragweed or timothy) from 0.1 to 100 mg were delivered to 29 patients, ages 20 to 31 yr with AR who were skin test positive or had elevated serum-IgE antibodies to ragweed or timothy but not pine pollen. Our results demonstrated ETO developed in four ears at 0.05 mg of pollen, in one at 0.5 mg, in four at 1 mg, in 28 at 10 mg, in 15 at 50 mg, and in two at 100 mg of pollen. ETO persisted from 2 to 120 hr. Dose responses and duration of ETO were compared to patients' serum-IgE antibodies that ranged from 3% to 36% B/T (median 26.4%). The patients with the highest serum-IgE antibody values (greater than or equal to 26.4%) required lower antigen-dose challenges (less than or equal to 10 mg) to develop ETO (p less than or equal to 0.01) that also persisted longer (less than or equal to 48 hr) p less than or equal to 0.05. Symptoms of AR developed with an antigen dose that was less than the antigen dose that resulted in the development of ETO in 22 patients and at the same antigen dose in the other seven subjects. At a later date, these same subjects were also challenged intranasally with 50 mg of pine pollen after which no symptoms of AR or development of ETO were noted. In summary, the expression of ETO after provocative intranasal pollen challenge in AR patients is an immune-mediated reaction that is antigen-dose dependent and related to serum-IgE antibody titer.

Adult↗
PubMed1999

Parasite infection and Japanese cedar pollinosis in monkeys.

To evaluate the relationship between helminthic parasite infection and sensitization to Japanese cedar (Cryptomeria japonica; CJ) pollen allergens in Japanese monkeys (Macaca fuscata), we examined the parasite infection, presence of anti-pollen allergen IgE and development of pollinosis. Serum samples and fecal specimens were taken from 169 monkeys in five troops, and the presence of IgE antibody for CJ pollen allergen and of helminthic parasite eggs in their feces was examined. Of the 169 monkeys, helminthic parasite eggs from 138 monkeys were detected. The frequency of anti-CJ IgE (19%) and the level of total IgE did not differ significantly between the monkeys with and without parasite eggs. We examined the presence of anti-CJ IgE and pollinosis symptoms in 31 monkeys of a troop; six of the monkeys demonstrated anti-CJ IgE and pollinosis symptoms. Five of these six monkeys had parasite eggs. We found that the monkeys that demonstrated anti-CJ IgE and pollinosis symptoms had helminthic parasite infections. These data suggest that helminthic parasite infection does not reduce the development of clinical signs of CJ pollinosis in Japanese monkeys.

Allergens↗
PubMed2000

The effects of pollen and seed migration on nuclear-dicytoplasmic systems. II. A new method for estimating plant gene flow from joint nuclear-cytoplasmic data.

A new maximum-likelihood method is developed for estimating unidirectional pollen and seed flow in mixed-mating plant populations from counts of joint nuclear-cytoplasmic genotypes. Data may include multiple unlinked nuclear markers with a single maternally or paternally inherited cytoplasmic marker, or with two cytoplasmic markers inherited through opposite parents, as in many conifer species. Migration rate estimates are based on fitting the equilibrium genotype frequencies under continent-island models of plant gene flow to the data. Detailed analysis of their equilibrium structures indicates when each of the three nuclear-cytoplasmic systems allows gene flow estimation and shows that, in general, it is easier to estimate seed than pollen migration. Three-locus nuclear-dicytoplasmic data only increase the conditions allowing seed migration estimates; however, the additional dicytonuclear disequilibria allow more accurate estimates of both forms of gene flow. Estimates and their confidence limits for simulated data sets confirm that two-locus data with paternal cytoplasmic inheritance provide better estimates than those with maternal inheritance, while three-locus dicytonuclear data with three modes of inheritance generally provide the most reliable estimates for both types of gene flow. Similar results are obtained for hybrid zones receiving pollen and seed flow from two source populations. An estimation program is available upon request.

Cell Nucleus↗
PubMed2004

Quaternary Ice-Age dynamics in the Colombian Andes: developing an understanding of our legacy.

Pollen records from lacustrine sediments of deep basins in the Colombian Andes provide records of vegetation history, the development of the floristic composition of biomes, and climate variation with increasing temporal resolution. Local differences in the altitudinal distribution of present-day vegetation belts in four Colombian Cordilleras are presented. Operating mechanisms during Quaternary Ice-Age cycles that stimulated speciation are discussed by considering endemism in the asteraceous genera Espeletia, Espeletiopsis and Coespeletia. The floristically diverse lower montane forest belt (1000-2300 m) was compressed by ca. 55% during the last glacial maximum (LGM) (20 ka), and occupied the slopes between 800 m and 1400 m during that period. Under low LGM atmospheric pCO2 values, C4-dominated vegetation, now occurring below 2200 m, expanded up to ca. 3500 m. Present-day C3-dominated paramo vegetation is therefore not an analogue for past C4-dominated vegetation (with abundant Sporobolus lasiophyllus). Quercus immigrated into Colombia 478 ka and formed an extensive zonal forest from 330 ka when former Podocarpus-dominated forest was replaced by zonal forest with Quercus and Weinmannia. During the last glacial cycle the ecological tolerance of Quercus may have increased. In the ecotone forests Quercus was rapidly and massively replaced by Polylepis between 45 and 30 ka illustrating complex forest dynamics in the tropical Andes.

Altitude↗
PubMed2002

Development of new IgE specificities to allergenic components in birch pollen extract during specific immunotherapy studied with immunoblotting and Pharmacia CAP System.

BACKGROUND: New IgE sensitizations to proteins in allergen extracts have been shown to occur during allergen-specific immunotherapy (IT). However little is known about the kinetics of the changes in antibody reactivities. METHODS: Twenty-four allergic children and adults were treated with birch pollen rush IT (RIT). Fifteen matched patients served as allergic controls. Sera were obtained at regular intervals for up to three years and analyzed with immunoblotting and Pharmacia CAP System with recombinant (r) birch pollen allergens (rBet v 1, rBet v 2, and rBet v 4). RESULTS: All birch-allergic patients had specific IgE to the major birch pollen allergen Bet v 1, but only three had IgE to rBet v 2 and/or rBet v 4 at the beginning of the study. New IgE sensitizations developed in 65% of the birch RIT-treated patients when studied by immunoblotting. Twenty-nine percent of the patients developed new sensitizations to rBet v 2 and/or rBet v 4 during RIT as measured by Pharmacia CAP System. Generally, new specific IgE reactivities occurred after at least one year of RIT, and only at low levels (< 1 kUA/l). CONCLUSIONS: Sensitization to additional allergenic pollen components frequently occurs during prolonged birch RIT. However, the IgE levels are low and the clinical relevance is not known.

Adolescent↗
PubMed1975

[Effect of dietary proteins on the multiplication of the protozoon Nosema apis Z].

By counting the spores of protozoon Nosema apis Z. in Bürker's chamber the author was able to find, in 1495 caged bees sacrificed one week after the parasite invasion, from altogether 26 samples of various feeds statistically sifnificant differences of influencing the protozoon development only in sallow pollen. The differences between the individual feeds were statistically more significant in bees sacrificed 14 days after the invasion. Examination of 1260 bees 14 days after the invasion demonstrated that, as compared with glycide food, the parasite development was enhanced by a feed consisting of 6, 9, and 12 per cent fresh rape pollen, 3 and 6 per cent of fresh and dried sallow pollen, 6 per cent freeze-dried pollen mixture, pollen deposited in honeycombs, 7.5, 10, and 12.5 per cent yeast dough, "Arnika" and 3 per cent Bacto peptone. Even 14 days after the invasion no statistically sifnificant differences of influencing the schizogony of protozoon Nosema apis Z. could be demonstrated in bees fed pure glycide feed, dough with 3 and 6 per cent casein hydrolyzate, 3 and 6 per cent Hammarsten casein, 3 per cent dried whole eggs, 3 per cent rape pollen and 3 and 6 per cent fresh pollen mixtures. In the study the possibility of an indirect effect of pollen on the parasite schizogony through the secrete of the pharyngeal glands is being discussed.

Animals↗
PubMed2004

Fine-scale genetic structure and gene dispersal in Centaurea corymbosa (Asteraceae) I. Pattern of pollen dispersal.

Pollen dispersal was characterized within a population of the narrowly endemic perennial herb, Centaurea corymbosa, using exclusion-based and likelihood-based paternity analyses carried out on microsatellite data. Data were used to fit a model of pollen dispersal and to estimate the rates of pollen flow and mutation/genotyping error, by developing a new method. Selfing was rare (1.6%). Pollen dispersed isotropically around each flowering plant following a leptokurtic distribution, with 50% of mating pairs separated by less than 11 m, but 22% by more than 40 m. Estimates of pollen flow lacked precision (0-25%), partially because mutations and/or genotyping errors (0.03-1%) could also explain the occurrence of offspring without a compatible candidate father. However, the pollen pool that fertilized these offspring was little differentiated from the adults of the population whereas strongly differentiated from the other populations, suggesting that pollen flow rate among populations was low. Our results suggest that pollen dispersal is too extended to allow differentiation by local adaptation within a population. However, among populations, gene flow might be low enough for such processes to occur.

Centaurea↗
PubMed1992

Evidence of cross-reactivity between olive, ash, privet, and Russian olive tree pollen allergens.

In a clinical investigation, 103 Michigan residents with symptoms suggestive of allergic rhinitis or asthma were skin tested with olive (Olea europaea) pollen extract. Nineteen had positive reactions. Since the olive tree is not native to nor grown in Michigan, this study was undertaken to determine whether the skin test reactivity was the result of cross-reactivity among tree pollen allergens. ELISAs were developed to measure olive, ash (Fraxinus americana), privet (Ligustrum vulgare), and Russian olive (Elaeagnus angustifolia) specific IgE antibodies. Inhibition studies were performed to determine whether pollen extracts from each of these tree species could inhibit IgE antibody binding to olive extracts. Eleven of the 19 skin test-positive patients were olive-ELISA positive, eight either were ELISA-positive to ash, seven to privet and ten to Russian olive. There were significant correlations between the ELISA results to olive and each of the other three pollens. The inhibition studies demonstrated that all three of the tree pollens were capable of inhibiting the binding of IgE to olive extract in a dose-response fashion. IgE-immunoblot studies demonstrated several proteins common to olive, ash, and privet. Twelve of the olive skin test-positive patients were contacted and 75% were exposed to one or more of the studied trees in their yards. Five patients had traveled to areas where olive trees are grown. We conclude that there is a high degree of cross-reactivity among allergens from native Michigan trees and from olive trees. This cross-reactivity is the most likely reason for skin test reactivity to olive pollen extract in Michigan.

Allergens↗