Plant Allergens Research Articles

Immunochemical and molecular characterization of allergenic profilin (Koc s 2) from Kochia scoparia pollen

Kochia scoparia pollen has been demonstrated as an important cause of pollinosis in tropical and sub-tropical regions of the world. The aim of this study was to characterize the IgE-binding protein of the Kochia pollen extract and production of recombinant form of allergenic profilin of this weed. To predict its allergenic cross-reactivity with profilins of common allergenic plants, nucleotide sequence homology of Kochia profilin was evaluated. Specific ELISA and immunoblotting assay were applied to determine the IgE-binding reactivity of 28 sera collected from patients who were sensitized to Kochia pollen. In cloning procedure, the Kochia profilin-coding sequence was inserted into PTZ57R/T vector and expressed using pET-21b(+) vector. IgE-binding competence of purified recombinant Kochia profilin (rKoc s 2) was analyzed by in vitro assays. There were several protein bands in Kochia pollen extract with molecular weights approximately ranging from 14.5 to 85 kDa. Nucleotide sequencing revealed an open reading frame of 399 bp encoding for 133 amino acid residues which belonged to the profilin family; 15 patients (15/28, 53.1 %) had significant specific IgE levels for the rKoc s 2. Immunodetection and inhibition assays indicated that the purified rKoc s 2 might be the same as that in the crude extract. Koc s 2, the first allergen from the Kochia pollen was identified as a member of the family of profilins. High degree of homology was found among amino acid sequences of Kochia profilin and several profilin molecules from unrelated plant families.

N-glycome profiling of patatins from different potato species of Solanum genus.

It is hypothesized that oligosaccharides are another potential source of immunological cross-reaction between different plant allergens. Patatin is the most abundant glycoprotein in potato and has been described to have an oligosaccharide of composition Man3(Xyl)GlcNAc2(Fuc). In this work, N-glycosylation profiles of patatin proteins isolated from tubers of different potato species were investigated and compared. Oligosaccharides were released by enzymatic digestion with PNAGase A and analyzed primarily by matrix-assisted laser desorption ionization mass spectrometry. For glycan labeling, a modified version of on-target derivatization with phenylhydrazine was applied. This study found the presence of glycan structures not described previously in patatins of potato tubers, and their glycan profiles significantly differed. This knowledge about the glycosylation of potato patatins may be helpful for correct choice of potato species to decrease the presence of specific glycan epitopes causing food allergy as well as for utilization of potatoes for the manufacture of therapeutic proteins.

IgE Sensitization to Lupine in Bakers - Cross-Reactivity or Co-Sensitization to Wheat Flour?

Background: Food allergy to lupine has frequently been reported in patients allergic to peanut or soy, and cross-reactivity between these legumes is known. Moreover, respiratory allergy to lupine has been described after inhalation, mostly at workplaces. Our aim was to study the frequency of lupine sensitization in European bakers with suspected bakers' allergy. Furthermore, associations between sensitizations to lupine and other plant allergens were investigated. Methods: One hundred and sixteen bakers with work-related allergic symptoms but without known food allergies were examined. Specific IgE (sIgE) antibodies to wheat flour, rye flour, lupine, peanut, soy and the recombinant single birch protein rBet v 1 were quantified. Selected sera were tested for cross-reactivity using ImmunoCAP inhibition and ISAC microarrays. Results: Whereas 67% of bakers were sensitized to wheat and/or rye flour, 35% showed sIgE to peanut and 33% to lupine. All lupine-positive bakers also had sIgE to either wheat flour (89%) and/or peanut (92%), and lupine sIgE correlated significantly with sIgE to peanut, soy, wheat and rye flour. Used as an inhibitor, wheat flour inhibited IgE binding to lupine in 4 out of 8 sera, indicating cross-reactivity. In microarrays, these sera showed IgE binding to lipid transfer proteins, profilins and/or cross-reactive carbohydrate determinants. Further inhibition experiments suggest that these single allergens are involved in cross-reactivity. Conclusion: One third of 116 symptomatic bakers showed sIgE to lupine. At least some of these sensitizations were based on cross-reactivity between lupine and wheat flour. However, the considerable sensitization rate could also be a sign that the use of lupine flour in bakeries may be of occupational relevance.

A Systematic Analysis of Pollen Transcriptomes from Plant Allergens Reveals Conserved Targets of Immune Responses

We have recently identified a set of novel antigens in Timothy grass (TG) pollen using an unbiased, integrated transcriptomic and proteomic analysis, and have shown that these antigens are prominent targets of T-cell responses. Here we determined the degree of conservation of these epitopes across multiple plant species that could be targets of cross-reactive T-cells. This would make them potential candidates for pan-pollen immunotherapy approaches. RNA was extracted and sequenced from nine plant allergens (4-grass, 2-weed, and 3-tree pollens). Peptides from TG were examined for conservation across these pollens using sequence alignments, and conservation was correlated with immunogenicity. T-cell epitope cross-reactivity was determined by generating short term mono-specific T-cell lines and assessing their response across the panel of pollen extracts in IL-5 ELISPOT assays. We find that conservation of a peptide across pollens based on transcriptomic analysis correlates with the likelihood that it will elicit Th2 responses in allergic donors. Furthermore, If TG extract elicited high responses after culture with peptide, so did those extracts in which the peptide is conserved. Substitutions of 3 or more residues in the peptide greatly reduced the response. Thus, conserved peptides (with 2 or less substitutions) are capable of inducing cross-reactive T-cell immune responses. We have identified peptides that are significantly conserved across multiple plant allergen species and stimulate cross-reactive T-cells. It is possible that inducing tolerance against these peptides may modulate the allergic immune response against a broad range of grass and pollen allergens.

A survey of plants responsible for causing allergic contact dermatitis in the Amathole District, Eastern Cape, South Africa

BackgroundAn inventory of allergenic plants can enable vulnerable individuals to discover the source of their dermatitis and thus prevent re-exposure. However, because of the relatively little data available in the scientific literature with regard to the adverse effects of plant, the aim of this study was to document the plants responsible for allergic contact dermatitis (ACD) in the Eastern Cape. Interview questions targeted the local names of plants that cause allergies when in direct contact with the skin. ResultsTwenty four plant species in 11 families were reported as causative agents of ACD. The Asteraceae was probably the most important allergenic plant family, represented by commonly used medicinal plants such as Artemisia afra, vegetables such as Lactuca sativa and weeds such as Conyza bonariensis. Sub-acute eczematous lesions of the face and the exposed areas of the upper limbs were characteristic of Asteraceae allergies. Out of the 24 plants mentioned for causing ACD, 67% are principally used as food. ConclusionsA high burden of occupational skin disease in the food industry will definitely translate into large costs in terms of days lost from work and adjustments necessary in the workplace. Therefore, health care practitioners need to be aware of possible occupational causes for all cases of ACD.

DISTRIBUTION OF ALLERGENIC PLANTS IN RUSSIA

We analyzed, for the first time ever, the geographical distribution of the main allergenic plants in Russia. All materials were organized as database and attached to the map in GIS Mapinfo. For each region of Russian Federation, two indices were calculated: the total number of allergenic plants in the region and the “allergenic index”. A series of maps was compiled: the number of spring-flowering species, the number of summer-flowering species, the total number of species flowering during the whole year, the overall allergen danger during spring and summer seasons, respectively, and the overall allergen danger during the whole year. In terms of the number of allergenic species and by the “allergenic index,” the most dangerous regions appeared to be the Ryazan and Voronezh Oblasts, while the less dangerous – the Chukotka Autonomous Okrug, and the Magadan Oblast. The maps may serve as a reference source for allergologists and allergy sufferers.

臨床診断に有効な植物性アレルゲンコンポーネント

臨床診断のゴールデンスタンダードは食物経口負荷試験であるが，負荷試験はアナフィラキシーなどの危険を伴うため，安全な検査によって負荷試験を行う患者をできるかぎり選別することが望まれている．しかし，粗抗原に対する特異的IgE抗体価での検査では，臨床的感度は高いものの，特異度が低いことが問題であり，診断効率は高くないことが多い．粗抗原に含まれる個々のアレルゲン（アレルゲンコンポーネント）の中には，その特異的IgE抗体価が臨床症状と相関するものが見出されている．本稿では，植物の種子のアレルゲンコンポーネントについて概説するとともに，負荷試験を行った検体を用いた解析から明らかになってきた診断に有効なコンポーネントについて紹介したい．

ERRATUM: Affiliation Correction. Evaluation of the association of vegetation of allergenic plants and pollinosis with meteorological changes

ERRATUM: Affiliation Correction. Evaluation of the association of vegetation of allergenic plants and pollinosis with meteorological changes

The comparison of pollen abundance in air and honey samples

Honey as a food has long been used in human nutrition and is still popular. Honey is important because of its therapeutic, prophylactic and strengthening value. Pollen is one of the most decisive components that ensure the quality and type of honey. Modern society becomes more and more sensitive to airborne pollen. Therefore, it is crucial to determine the composition of allergenic plant pollen in natural honey. For this purpose, we studied and compared pollen abundance in honey and air samples collected in Lithuania. Standard methods for pollen investigation in air and honey were used in this study. The botanical diversity of pollen identified in honey and air samples indicates 10 morphotypes: 8 of woody plants and 2 of herbaceous plants, in both the honey and air samples. <em>Salix</em> pollen counts in the honey were found to be highest among airborne pollen from May to September. The anemophilous allergenic pollen constituted 44 % of the total pollen detected in the honey.

Allergenic and Toxic Compounds in Ornamental Plants – A review

Various biosynthesised compounds from ornamental plants can be harmful to man, throughout a plant’s entire life cycle or only during certain moments, present in all of its organs or restricted only to some. Interdisciplinary research regarding plant toxins and allergens are being conducted worldwide, aiming to prevent the production of diseases. The research aimed to phytochemically classify vegetal compounds with toxic and allergenic characteristics found in ornamental plants, to identify the main pathogenic pathways through which these compounds act and to come up with recommendations regarding valorification of these plants. The study focuses on ornamental plants in both spontaneous and cultivated flora, in protected or unprotected spaces, commonly met in Romania. The current review includes vegetal allergens in the toxic vegetal substances group, from the perspective of modern definitions of toxicity. Based on phytochemical criteria, a classification of toxic vegetal compounds (including allergens) was achieved. Common native toxic ornamentals from our habitat are tabulated. Some non-native species were included on the basis of their high presence as house plants. Correlated to the commercial practices in Romania, the risks for ambient health were identified, both at the work place, at home and in the public space. Ornamentals can be dangerous to man’s health. The majority of toxic and allergenic substances (excluding pollens) are secondary metabolism compounds. Given these risk factors to health, it is necessary to impose health and safety regulations at work, to inform the general population regarding potential negative effects and to commercialize plants with labels which should contain warnings about the risk of diseases or the aggravation of existing ones.

Spatial and temporal variations of pollen concentrations in Islamabad (Pakistan): effect of meteorological parameters and impact on human health

This study focuses on the identification and quantification of airborne pollen grains from allergenic plant species and their relationship with meteorological factors, i.e. maximum and minimum daily temperature, relative humidity, rainfall and wind speed in the city of Islamabad, Pakistan. An aerobiological data set (2010–2012), collected using rotorod samplers in five different sectors of the city, was supplied by the Pakistan Meteorological Department. Pollen of eight allergenic species was identified amongst which Broussonetia papyrifera exceeded the highest pollen level and, therefore, likely played a key role in aggravating the symptoms of pollen allergy in the city. The mean weekly pollen counts were next correlated with the weekly number of allergic patients visiting hospitals during 2010–2011. Clinical data were acquired from the Pakistan Institute of Medical Sciences. The highest number of allergic patients visiting hospital was usually observed during weeks with high pollen level. These results suggest a close relationship between the pollen concentration in the air and the allergy symptoms. Spearman’s rank correlation analysis was performed to establish the relationships between meteorological parameters and daily average pollen counts. A pollen calendar for the Islamabad city was also prepared to provide a guide for the timing and duration of season for all encountered pollen types.

Use of Humanised Rat Basophilic Leukaemia Cell Line RS-ATL8 for the Assessment of Allergenicity of Schistosoma mansoni Proteins

BackgroundParasite-specific IgE is thought to correlate with protection against Schistosoma mansoni infection or re-infection. Only a few molecular targets of the IgE response in S. mansoni infection have been characterised. A better insight into the basic mechanisms of anti-parasite immunity could be gained from a genome-wide characterisation of such S. mansoni allergens. This would have repercussions on our understanding of allergy and the development of safe and efficacious vaccinations against helminthic parasites.Methodology/Principal FindingsA complete medium- to high-throughput amenable workflow, including important quality controls, is described, which enables the rapid translation of S. mansoni proteins using wheat germ lysate and subsequent assessment of potential allergenicity with a humanised Rat Basophilic Leukemia (RBL) reporter cell line. Cell-free translation is completed within 90 minutes, generating sufficient amounts of parasitic protein for rapid screening of allergenicity without any need for purification. Antigenic integrity is demonstrated using Western Blotting. After overnight incubation with infected individuals' serum, the RS-ATL8 reporter cell line is challenged with the complete wheat germ translation mixture and Luciferase activity measured, reporting cellular activation by the suspected allergen. The suitability of this system for characterization of novel S. mansoni allergens is demonstrated using well characterised plant and parasitic allergens such as Par j 2, SmTAL-1 and the IgE binding factor IPSE/alpha-1, expressed in wheat germ lysates and/or E. coli. SmTAL-1, but not SmTAL2 (used as a negative control), was able to activate the basophil reporter cell line.Conclusion/SignificanceThis method offers an accessible way for assessment of potential allergenicity of anti-helminthic vaccine candidates and is suitable for medium- to high-throughput studies using infected individual sera. It is also suitable for the study of the basis of allergenicity of helminthic proteins.

Human antibody response to N-glycans present on plant-made influenza virus-like particle (VLP) vaccines

BackgroundPlant-made biotherapeutics are gathering momentum and some plant glycoproteins are allergens. Glycans with core β1-2xylose and α1,3fucose motifs and antennae terminated by mannose residues (e.g.: MMXF) are found on several plant allergens and can cross-react with glyco-epitopes from other sources. To date, reactivity to these cross-reactive determinants has not been associated with clinical symptoms. ObjectiveWe produced VLP vaccines bearing the hemagglutinin(HA) of H5(A/Indonesia/5/05) or H1(A/California/07/09) influenza viruses by transfection of Nicotiana benthamiana. Subjects enrolled in Phase I/II trials were followed for evidence of allergy/hypersensitivity and development of antibodies against plant glyco-epitopes. MethodsA total of 280/349 subjects received either one (H1) or 2 doses (H5) of vaccine (5–45μg of HA/dose) intramuscularly including 40 with pre-existing plant allergies. Subjects were monitored for 6 months. IgG and IgE to plant glyco-epitopes were measured by ELISA using corn-/egg-derived avidin and bromelain as target antigens. ResultsNo subject developed allergic/hypersensitivity symptoms. Some (34%) developed transient IgG and, in some cases IgE, to plant glyco-epitopes but no subject mounted an IgE response to the MMXF motif. Antibodies returned to baseline by 6 months in most subjects. ConclusionVLP vaccines bearing influenza HA glycoproteins can elicit transient IgG and, in some cases, IgE responses that are not associated with either the development or worsening of allergic/hypersensitivity symptoms.

The airborne pollen calendar for Lublin, central-eastern Poland.

An aerobiological study was conducted to investigate the quantity and quality of pollen in the atmosphere of Lublin in central-eastern Poland. Pollen monitoring was carried out in the period 2001-2012 using a Hirst-type volumetric spore trap. The atmospheric pollen season in Lublin lasted, on average, from the end of January to the beginning of October. The mean air temperature during the study period was found to be higher by 1.1 °C than the mean temperature in the period 1951-2000. 56 types of pollen of plants belonging to 41 families were identified. 28 types represented woody plants and 28 represented herbaceous plants. The study distinguished 5 plant taxa the pollen of which was present most abundantly in the air of Lublin, which altogether accounted for 73.4%: Betula, Urtica, Pinus, Poaceae, and Alnus. The mean annual pollen index was 68 706; the largest amount of pollen was recorded in April and accounted for 33.3% of the annual pollen index. The pollen calendar included 28 allergenic plant taxa. The pollen of woody plants had the highest percentage in the pollen spectrum, on average 58.4%. The parameters of the pollen calendar for Lublin were compared with the calendar for central-eastern Europe with regard to the start of the pollen season of particular taxa. The pollen calendar for Lublin was demonstrated to show greater similarity to the calendar for Münster (Germany) than to the calendar for Bratislava (Slovakia).

Primary Identification, Biochemical Characterization, and Immunologic Properties of the Allergenic Pollen Cyclophilin Cat r 1

Cyclophilin (Cyp) allergens are considered pan-allergens due to frequently reported cross-reactivity. In addition to well studied fungal Cyps, a number of plant Cyps were identified as allergens (e.g. Bet v 7 from birch pollen, Cat r 1 from periwinkle pollen). However, there are conflicting data regarding their antigenic/allergenic cross-reactivity, with no plant Cyp allergen structures available for comparison. Because amino acid residues are fairly conserved between plant and fungal Cyps, it is particularly interesting to check whether they can cross-react. Cat r 1 was identified by immunoblotting using allergic patients' sera followed by N-terminal sequencing. Cat r 1 (∼ 91% sequence identity to Bet v 7) was cloned from a cDNA library and expressed in Escherichia coli. Recombinant Cat r 1 was utilized to confirm peptidyl-prolyl cis-trans-isomerase (PPIase) activity by a PPIase assay and the allergenic property by an IgE-specific immunoblotting and rat basophil leukemia cell (RBL-SX38) mediator release assay. Inhibition-ELISA showed cross-reactive binding of serum IgE from Cat r 1-allergic individuals to fungal allergenic Cyps Asp f 11 and Mala s 6. The molecular structure of Cat r 1 was determined by NMR spectroscopy. The antigenic surface was examined in relation to its plant, animal, and fungal homologues. The structure revealed a typical cyclophilin fold consisting of a compact β-barrel made up of seven anti-parallel β-strands along with two surrounding α-helices. This is the first structure of an allergenic plant Cyp revealing high conservation of the antigenic surface particularly near the PPIase active site, which supports the pronounced cross-reactivity among Cyps from various sources.

Molecular aerobiology - Plantago allergen Pla l 1 in the atmosphere.

Exposure to airborne pollen from certain plants can cause allergic disease, but allergens can also be found in non-pollen-bearing fractions of ambient air. This may explain why the allergic response in susceptible patients does not always coincide with the presence and magnitude of airborne pollen counts. Plantago pollen is an important cause of pollinosis in northern Mediterranean countries, but it is difficult to determine its incidence in allergies because Plantago pollen appears in the atmosphere at the same time as grass pollen. The study aimed to investigate the relationship between the atmospheric concentration of Pla l 1 aeroallergen and Plantago pollen, and its incidence in a population group. Pollen was sampled using a Hirst-type volumetric trap (Burkard) and Burkard Cyclone sampler (Burkard) for Pla l 1 allergen. Allergen was determined with a Pla l 1-specific ELISA. Serum-specific IgE levels to several plant allergens were measured with the EAST system. The aerobiological dynamics of Plantago pollen grains and Pla l 1 did not follow the same trend, whereas the sum of Plantago with some other pollen types showed a more similar behaviour. Of the 118 subjects tested, sera from 52 contained IgE to Plantago pollen, but only 5 were monosensitized. The presence of Pla l 1 in the atmosphere depends not only on Plantago pollen but also on the pollen of other species from the Oleaceae family. Knowledge of the behaviour of allergen Pla l 1 in the atmosphere can help understand better asthma exacerbations associated with aeroallergens.

Immunochemical characterization of acacia pollen allergens and evaluation of cross-reactivity pattern with the common allergenic pollens.

Pollen from the Acacia has been reported as an important source of pollinosis in tropical and subtropical regions of the world. The aim of this study was to characterize the IgE binding protein of Acacia farnesiana pollen extract and evaluate cross-reactivity with the most allergenic pollens. In this study, pollen extract was fractionated by SDS-PAGE and the allergenic profile was determined by IgE-immunoblotting and specific ELISA using forty-two Acacia allergic patients. Potential cross-reactivity among Acacia and selected allergenic plants was evaluated with ELISA and immunoblotting inhibition experiments. There were several resolved protein fractions on SDS-PAGE which ranged from 12 to 85 kDa. Several allergenic protein bands with molecular weights approximately between 12 and 85 kDa were recognized by IgE-specific antibodies from Acacia allergic patients in the immunoblot assay. The inhibition by the Prosopis juliflora pollen extract was more than those by other pollen extracts. Moreover, the wheal diameters generated by the Acacia pollen extract were highly correlated with those of P. juliflora pollen extracts. The findings suggest that several proteins such as 15, 23, 45, and 50 kDa proteins could be used as diagnostic and therapeutic reagents for patients allergic to A. farnesiana and P. juliflora.

The role of N‐glycosylation in kiwi allergy

The physical, biochemical, and immunological characteristics of plant allergens have been widely studied, but no definite conclusion has been reached about what actually makes a protein an allergen. In this sense, N-glycosylation is an exclusive characteristic of plant allergens not present in mammals and it could be implied in allergenic sensitization. With this aim, we evaluated and compared the allergenic activity of the protein fraction and the N-glycan fraction of the thaumatin-like protein and the main kiwi allergen, Act d 2. The natural allergen, Act d 2, was deglycosylated by trifluoromethanesulfonic acid treatment; the N-glycan fraction was obtained by extended treatment with proteinase K. N-glycan- and protein- fractions were recognized by specific IgE of kiwi-allergic patients. By contrast, the sugar moiety showed a reduced capacity to activate basophils and T cells, but not dendritic cells derived from patients' monocytes. Related to this, the production of cytokines such as IL6 and IL10 was increased by the incubation of dendritic cells with sugar moiety. Thus, the sugar moiety plays a significant role in sensitization, inducing the activation of antigen-presenting cells, but it is the protein fraction that is responsible for the allergic reactions.

Environmental changes could enhance the biological effect of Hop J pollens on human airway epithelial cells

Environmental changes could enhance the biological effect of Hop J pollens on human airway epithelial cells

European Directive Fragrances in Natural Products

Information on the presence of European Directive fragrance (EUF) allergens in plants and foods is important for numerous reasons. If an individual is allergic to an EUF and is avoiding fragrance, it is possible that they may still be exposed to the allergen in a natural product. In addition, because many of these allergens are also found in foods, it is possible that ingestion of a food containing the allergen may induce systemic contact allergy. Finally, individuals with lip dermatitis may react to contact with foods that contain the allergen. In this article, we have used the data available to identify which plants and foods contain EUF. When available, concentrations of EUF in natural products are provided. The goal of this article is to narrow down the list of botanicals to avoid for specific EUF allergies.