Molecular cloning of major allergen from Cupressus arizonica pollen: Cup a 1

EAACI Molecular Allergology User's Guide 2.0

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

Identification of Potential IgE-Binding Epitopes Contributing to the Cross-Reactivity of the Major Cupressaceae Pectate-Lyase Pollen Allergens (Group 1)

Pectate-lyase allergens, the group 1 of allergens from Cupressaceae pollen, consist of glycoproteins exhibiting an extremely well-conserved three-dimensional structure and sequential IgE-binding epitopes. Up to 10 IgE-binding epitopic regions were identified on the molecular surface, which essentially cluster at both extremities of the long, curved β-prism-shaped allergens. Most of these IgE-binding epitopes possess very similar conformations that provide insight into the IgE-binding cross-reactivity and cross-allergenicity commonly observed among Cupressaceae pollen allergens. Some of these epitopic regions coincide with putative N-glycosylation sites that most probably consist of glycotopes or cross-reactive carbohydrate determinants, recognized by the corresponding IgE antibodies from allergic patients. Pectate-lyase allergens of Cupressaceae pollen offer a nice example of structurally conserved allergens that are widely distributed in closely-related plants (Chamæcyparis, Cryptomeria, Cupressus, Hesperocyparis, Juniperus, Thuja) and responsible for frequent cross-allergenicity.

Allergenicity at component level of sub-pollen particles from different sources obtained by osmolar shock: A molecular approach to thunderstorm-related asthma outbreaks

BACKGROUND

The so-called "thunderstorm asthma" (TA) is an uncommon but dramatic outbreak of asthma attacks occurring during a thunderstorm in the pollen and moulds season. Mechanisms which make the pollen able to enter the deeper airways and provoke severe asthma symptoms are still unclear.

OBJECTIVE

To test the hypothesis that sub-pollen particles (SPPs) originated from the rupture by an osmotic shock of pollen associated with TA contain allergens.

METHODS

After hydration, SPPs released from pollen grains of grass, pellitory, olive, cypress, ragweed and birch were isolated and determined by microscopy. Allergens were determined by in vitro ELISA inhibition tests indirectly using the sera from 10 polyreactive patients. An inhibition <50% was considered as negative, 50%-75% moderate and > 75% complete.

RESULTS

The inhibition experiments showed that the SPPs from birch and cypress were unable to inhibit serum IgE reactivity to Bet v 1 and Cup a 1, respectively. Ragweed SPPs inhibited ragweed pollen extract and Amb a 1 by 75.8 ± 0.11% and 81.2 ± 0.15%, respectively. Olive and pellitory SPPs retained almost the whole IgE-binding capability in all cases tested. Grass SPPs inhibited 32 ± 0.06% of Lolium perenne Lol p 1 and 65% of Phleum pratense extracts, but results were highly variable for individual allergens (97.5%-0.03% for Phl p 2, 45.3 ± 0.12% for Phl p 5, 24.7 ± 0.22% for Phl p 6, and 38.3 ± 0.2% for Phl p 1).

CONCLUSIONS

Inhibition experiments confirm the hypothesis that SSPs obtained after the osmotic shock of pollen involved in TA, namely grass, pellitory and olive tree pollen, contain allergens and therefore they can induce severe asthma attacks during thunderstorms.

Distinguishing allergens from non-allergenic homologues using Physical-Chemical Property (PCP) motifs

Quantitative guidelines to distinguish allergenic proteins from related, but non-allergenic ones are urgently needed for regulatory agencies, biotech companies and physicians. In a previous study, we found that allergenic proteins populate a relatively small number of protein families, as characterized by the Pfam database. However, these families also contain non-allergenic proteins, meaning that allergenic determinants must lie within more discrete regions of the sequence. Thus, new methods are needed to discriminate allergenic proteins within those families. Physical-Chemical Properties (PCP)-motifs specific for allergens within a Pfam class were determined for 17 highly populated protein domains. A novel scoring method based on PCP-motifs that characterize known allergenic proteins within these families was developed, and validated for those domains. The motif scores distinguished sequences of allergens from a large selection of 80,000 randomly selected non-allergenic sequences. The motif scores for the birch pollen allergen (Bet v 1) family, which also contains related fruit and nut allergens, correlated better than global sequence similarities with clinically observed cross-reactivities among those allergens. Further, we demonstrated that the average scores of allergen specific motifs for allergenic profilins are significantly different from the scores of non-allergenic profilins. Several of the selective motifs coincide with experimentally determined IgE epitopes of allergenic profilins. The motifs also discriminated allergenic pectate lyases, including Jun a 1 from mountain cedar pollen, from similar proteins in the human microbiome, which can be assumed to be non-allergens. The latter lacked key motifs characteristic of the known allergens, some of which correlate with known IgE binding sites.

Safety and long-term immunological effects of CryJ2-LAMP plasmid vaccine in Japanese red cedar atopic subjects: A phase I study

Japanese Red Cedar (JRC) pollen induced allergy affects one third of Japanese and the development of effective therapies remains an unachieved challenge. We designed a DNA vaccine encoding CryJ2 allergen from the JRC pollen and Lysosomal Associated Membrane Protein 1 (LAMP-1) to treat JRC allergy. These Phase IA and IB trials assessed safety and immunological effects of the investigational CryJ2-LAMP DNA vaccine in both non-sensitive and sensitive Japanese expatriates living in Honolulu, Hawaii. In the Phase IA trial, 6 JRC non-sensitive subjects and 9 JRC and/or Mountain Cedar (MC) sensitive subjects were given 4 vaccine doses (each 4mg/1ml) intramuscularly (IM) at 14-day intervals. Nine JRC and/or MC sensitive subjects were given 4 doses (2 mg/0.5 ml) IM at 14-day intervals. The safety and functional biomarkers were followed for 132 d. Following this, 17 of 24 subjects were recruited into the IB trial and received one booster dose (2 mg/0.5 ml) IM approximately 300 d after the first vaccination dose to which they were randomized in the first phase of the trial. All safety endpoints were met and all subjects tolerated CryJ2-LAMP vaccinations well. At the end of the IA trial, 10 out of 12 JRC sensitive and 6 out of 11 MC sensitive subjects experienced skin test negative conversion, possibly related to the CryJ2-LAMP vaccinations. Collectively, these data suggested that the CryJ2-LAMP DNA vaccine is safe and may be immunologically effective in treating JRC induced allergy.

Prevalence of allergic sensitization to conifer pollen in a high cypress exposure area

Background:

Sensitization to Pinales (Cupressaceae and Pinaceae) has increased dramatically in recent years. The prevalence of sensitization in different geographic areas is related to exposure to specific pollens.

Objectives:

To investigate the prevalence of allergy to different conifer pollens, describe the characteristics of patients with such allergy, and identify the involved allergens.

Methods:

Patients were recruited at five hospitals near Madrid. Extracts from conifer pollen were prepared and used in skin-prick testing. Wheal sizes were recorded, and serum samples obtained from patients with positive reactions to Cupressus arizonica and/or Pinus pinea. The specific immunoglobulin E value to C. arizonica and Cup a 1 was determined. Individual immunoblots for each patient and with a pool of sera were performed. Allergenic proteins were sequenced by using liquid chromatography-tandem mass spectrometry.

Results:

Of 499 individuals included in the study, 17 (14%) had positive skin-prick test results to some conifer pollen extracts. Sixty-four patients had positive results to C. arizonica (prevalence 12.8%) and 11 had positive results to P. pinea (2.2%). All the patients had respiratory symptoms (61.4% during the C. arizonica pollination period), and 62.9% had asthma. Approximately 86% of the patients had positive specific immunoglobulin E results to C. arizonica and 92.3% had positive results to Cup a 1. Fourteen different bands were recognized by immunoblot; the most frequent bands were those detected at 43, 18, 16, and 14 kDa. All sequenced proteins corresponded to Cup a 1.

Conclusion:

Allergy to conifer pollen could be considered a relevant cause of respiratory allergy in central Spain. Asthma was more frequent than in other studies. We only identified Cup a 1 as involved in sensitization.

EAACI Molecular Allergology User's Guide

The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients.

The Pollen Coat Proteome: At the Cutting Edge of Plant Reproduction

The tapetum is a single layer of secretory cells which encloses the anther locule and sustains pollen development and maturation. Upon apoptosis, the remnants of the tapetal cells, consisting mostly of lipids and proteins, fill the pits of the sculpted exine to form the bulk of the pollen coat. This extracellular matrix forms an impermeable barrier that protects the male gametophyte from water loss and UV light. It also aids pollen adhesion and hydration and retains small signaling compounds involved in pollen-stigma communication. In this study, we have updated the list of the pollen coat's protein components and also discussed their functions in the context of sexual reproduction.

Tree pollen allergens-an update from a molecular perspective

It is estimated that pollen allergies affect approximately 40% of allergic individuals. In general, tree pollen allergies are mainly elicited by allergenic trees belonging to the orders Fagales, Lamiales, Proteales, and Pinales. Over 25 years ago, the gene encoding the major birch pollen allergen Bet v 1 was the first such gene to be cloned and its product characterized. Since that time, 53 tree pollen allergens have been identified and acknowledged by the WHO/IUIS allergen nomenclature subcommittee. Molecule‐based profiling of allergic sensitization has helped to elucidate the immunological connections of allergen cross‐reactivity, whereas advances in biochemistry have revealed structural and functional aspects of allergenic proteins. In this review, we provide a comprehensive overview of the present knowledge of the molecular aspects of tree pollen allergens. We analyze the geographic distribution of allergenic trees, discuss factors pivotal for allergic sensitization, and describe the role of tree pollen panallergens. Novel allergenic tree species as well as tree pollen allergens are continually being identified, making research in this field highly competitive and instrumental for clinical applications.

Pectate lyase pollen allergens: sensitization profiles and cross-reactivity pattern

Background

Pollen released by allergenic members of the botanically unrelated families of Asteraceae and Cupressaceae represent potent elicitors of respiratory allergies in regions where these plants are present. As main allergen sources the Asteraceae species ragweed and mugwort, as well as the Cupressaceae species, cypress, mountain cedar, and Japanese cedar have been identified. The major allergens of all species belong to the pectate lyase enzyme family. Thus, we thought to investigate cross-reactivity pattern as well as sensitization capacities of pectate lyase pollen allergens in cohorts from distinct geographic regions.

Methods

The clinically relevant pectate lyase pollen allergens Amb a 1, Art v 6, Cup a 1, Jun a 1, and Cry j 1 were purified from aqueous pollen extracts, and patients´ sensitization pattern of cohorts from Austria, Canada, Italy, and Japan were determined by IgE ELISA and cross-inhibition experiments. Moreover, we performed microarray experiments and established a mouse model of sensitization.

Results

In ELISA and ELISA inhibition experiments specific sensitization pattern were discovered for each geographic region, which reflected the natural allergen exposure of the patients. We found significant cross-reactivity within Asteraceae and Cupressaceae pectate lyase pollen allergens, which was however limited between the orders. Animal experiments showed that immunization with Asteraceae allergens mainly induced antibodies reactive within the order, the same was observed for the Cupressaceae allergens. Cross-reactivity between orders was minimal. Moreover, Amb a 1, Art v 6, and Cry j 1 showed in general higher immunogenicity.

Conclusion

We could cluster pectate lyase allergens in four categories, Amb a 1, Art v 6, Cup a 1/Jun a 1, and Cry j 1, respectively, at which each category has the potential to sensitize predisposed individuals. The sensitization pattern of different cohorts correlated with pollen exposure, which should be considered for future allergy diagnosis and therapy.

The effect of component-resolved diagnosis on specific immunotherapy prescription in children with hay fever

BACKGROUND

Sensitization to profilins and other cross-reacting molecules might hinder proper specific immunotherapy (SIT) prescription in polysensitized patients with pollen-related allergic rhinitis (AR). In these patients, component-resolved diagnosis (CRD) might modify SIT prescription by improving the identification of the disease-eliciting pollen sources.

OBJECTIVES

We sought to measure the effect of CRD on SIT prescription in children with pollen-related AR.

METHODS

Children (n = 651) with moderate-to-severe pollen-related AR were recruited between May 2009 and June 2011 in 16 Italian outpatient clinics. Skin prick test (SPT) reactivity to grass, cypress, olive, mugwort, pellitory, and/or Betulaceae pollen was considered clinically relevant if symptoms occurred during the corresponding peak pollen season. IgE sensitization to Phl p 1, Phl p 5, Bet v 1, Cup a 1, Art v 1, Ole e 1, Par j 2, and Phl p 12 (profilin) was measured by using ImmunoCAP. SIT prescription was modeled on SPT responses first and then remodeled considering also CRD according to GA(2)LEN-European Academy of Allergology and Clinical Immunology guidelines and the opinions of 14 pediatric allergists.

RESULTS

No IgE to the respective major allergens was detected in significant proportions of patients with supposed clinically relevant sensitization to mugwort (45/65 [69%]), Betulaceae (146/252 [60%]), pellitory (78/257 [30%]), olive (111/390 [28%]), cypress (28/184 [15%]), and grass (56/568 [10%]). IgE to profilins, polcalcins, or both could justify 173 (37%) of 464 of these SPT reactions. After CRD, the SPT-based decision on SIT prescription or composition was changed in 277 (42%) of 651 or 315 (48%) of 651 children according to the European or American approach, respectively, and in 305 (47%) of 651 children according to the opinion of the 14 local pediatric allergists.

CONCLUSIONS

In children with pollen-related AR, applying CRD leads to changes in a large proportion of SIT prescriptions as opposed to relying on clinical history and SPT alone. The hypothesis that CRD-guided prescription improves SIT efficacy deserves to be tested.

A molecular diagnostic algorithm to guide pollen immunotherapy in southern Europe: towards component-resolved management of allergic diseases

Correct identification of the culprit allergen is an essential part of diagnosis and treatment in immunoglobulin E (IgE)-mediated allergic diseases. In recent years, molecular biology has made important advances facilitating such identification and overcoming some of the drawbacks of natural allergen extracts, which consist of mixtures of various proteins that may be allergenic or not, specific for the allergen source or widely distributed (panallergens). New technologies offer the opportunity for a more accurate component-resolved diagnosis, of benefit especially to polysensitized allergic patients. The basic elements of molecular diagnostics with potential relevance to immunotherapy prescription are reviewed here, with a focus on Southern European sensitization patterns to pollen allergens. We propose a basic algorithm regarding component-resolved diagnostic work-up for pollen allergen-specific immunotherapy candidates in Southern Europe; this and similar algorithms can form the basis of improved patient management, conceptually a 'Component-Resolved Allergy Management'.

Prevalence and real clinical impact of Cupressus sempervirens and Juniperus communis sensitisations in Tuscan "Maremma", Italy

OBJECTIVE

The aim was to evaluate the impact of Cupressus sempervirens (Cs) and Juniperus communis (Jc) sensitisations in "Maremma" in southern Tuscany.

METHODS

811 consecutive outpatients (357 F - 57.86%; age: 36.9 ± 16.6) with suspected allergic respiratory symptoms underwent skin prick tests (SPT) for common allergens and for Cs and Jc.

RESULTS

SPT resulted negative in 295 (36.37%) subjects. A Cs/Jc sensitisation was found in 294 (36.25%): 289 (98.3%) were sensitised to Cs whereas 198 (67.34%) to Jc. There was a co-sensitisation between Cs and Jc in 193 (65.6%) subjects. Cs/Jc mono-sensitisation was found in 39 (13.6%) subjects. A higher number (p<0.0001) of Cs/Jc sensitised subjects reported winter (131-44.55%) and spring (124-42.2%) symptoms compared to Cs/Jc non-sensitised and non-allergic subjects. Most Cs/Jc sensitised subjects reported rhinitis and conjunctivitis (p<0.0001), whereas only few reported coughing and asthma (p<0.01). The most frequent co-sensitisation was with grass, olive and other trees in Cs/Jc subjects (p<0.001). Those who reported winter symptoms, likely influenced by Cupressaceae, rhinitis was the main symptom whereas asthma was less frequent. Cs/Jc sensitisation resulted to be a risk factor (OR: 1.73 [CI95% 1.18-2.55]) for rhinitis whereas the probability of being asthmatic was reduced (OR: 0.62 [CI95% 0.44-0.85]).

CONCLUSION

The prevalence of Cs/Jc sensitisation is about 36% in "Maremma". However, only in 44% of the patients, Cs/Jc seem to cause typical winter symptoms. Rhinitis is the predominant symptom, whereas asthma is less frequent. Testing Cupressaceae sensitisation using Jc pollen extract, rather than Cs, may result to be less sensitive.

A modified protocol for RNA isolation from high polysaccharide containing Cupressus arizonica pollen. Applications for RT-PCR and phage display library construction

RNA isolation is the first step in the study of gene expression and recombinant protein production. However, the isolation of high quantity and high-quality RNA from tissues containing large amounts of polysaccharides has proven to be a difficult process. Cupressus arizonica pollen, in addition to containing high polysaccharide levels, is a challenging starting material for RNA isolation due to the roughness of the pollen grain's walls. Here, we describe an improved technique for RNA isolation from C. arizonica pollen grains. The protocol includes a special disruption and homogenization process as well as a two-step modified RNA isolation technique which consists of an acid phenol extraction followed by a final cleanup using a commercial kit. Resulting RNA proved to be free of contaminants as determined by UV spectrophotometry. The quality of the RNA was analyzed on a bioanalyzer and showed visible 25S and 18S bands. This RNA was successfully used in downstream applications such as RT-PCR and phage display library construction.

Desloratadine for the treatment of cypress pollen-induced allergic rhinitis

BACKGROUND

Few studies have been conducted to assess treatment options for patients with sensitivities to cypress pollens, important triggers of allergic rhinitis (AR) in the Mediterranean region.

OBJECTIVE

To evaluate the effect of desloratadine, a second-generation antihistamine, on AR symptoms caused by cypress pollens native to France.

METHODS

Adults (N=233) with symptomatic cypress pollen allergies were randomized to receive desloratadine, 5 mg, or placebo daily for 15 days during 2 consecutive cypress pollen seasons. The primary end point was the percentage change from baseline in morning total nasal symptom scores on day 14; secondary assessments included total symptom score, peak nasal inspiratory flow, the Rhinoconjunctivitis Quality of Life Questionnaire, and global response to therapy.

RESULTS

On day 14, the desloratadine group had a significantly greater percentage decrease in total nasal symptom score vs the placebo group (-40% vs. -30%; P < .04). Similarly, on day 14, there was a 47% and 37% respective decrease in total symptom score (P = .01). Mean peak nasal inspiratory flow scores showed numeric, albeit not statistically significant, improvements from baseline through day 14 with desloratadine. A significantly greater improvement in Rhinoconjunctivitis Quality of Life Questionnaire scores occurred with desloratadine vs placebo on day 14 (-1.4 vs. -0.9; P = .004). The mean global response to therapy was better with desloratadine vs placebo (3.4 vs. 3.9; P = .004). The adverse event rate was similar in both groups.

CONCLUSION

Desloratadine is efficacious and safe for the treatment of AR induced by cypress pollens; it also improved disease-related quality of life.

Complementary roles for lipid and protein allergens in triggering innate and adaptive immune systems

BACKGROUND

Recent advances in allergy research mostly focussed on two major headings: improving protein allergen purification, which is aimed towards a better characterization of IgE- and T-cell reactive epitopes, and the potential new role for unconventional innate and regulatory T cells in controlling airway inflammation. These advancements could appear to be in conflict each other, as innate T cells have a poorly-defined antigen specificity that is often directed toward nonprotein substances, such as lipids.

METHOD

To reconcile these contrasting findings, the model of cypress pollinosis as paradigmatic for studying allergic diseases in adults is suggested.

RESULTS

The biochemical characterization of major native protein allergens from undenatured pollen grain demonstrated that the most relevant substance with IgE-binding activity is a glycohydrolase enzyme, which easily denaturizes in stored grains. Moreover, lipids from the pollen membrane are implicated in early pollen grain capture and recognition by CD1(+) dendritic cells (DC) and CD1-restricted T lymphocytes. These T cells display Th0/Th2 functional activity and are also able to produce regulatory cytokines, such as IL-10 and TGF-beta. CD1(+) immature DCs expand in the respiratory mucosa of allergic subjects and are able to process both proteins and lipids.

CONCLUSION

A final scenario may suggest that expansion and functional activation of CD1(+) DCs is a key step for mounting a Th0/Th2-deviated immune response, and that such innate response does not confer long-lasting protective immunity.

Characterization of pollen dispersion in the neighborhood of Tokyo, Japan in the spring of 2005 and 2006

The behavior of Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa) pollens in an urban area was examined through the measurements of the dispersion characteristics at the various sampling locations in both outdoor and indoor environments. Airborne pollens were counted continuously for three months during the Japanese cedar pollen and Japanese cypress seasons in 2005 and 2006 by the use of Durham's pollen trap method in and around Tokyo, Japan. The dispersion of pollens at the rooftop of Kyoritsu Women's University was observed to be at extremely high levels in 2005 compared with previously reported results during the past two decades. As for Japanese cedar pollen, the maximum level was observed as 440 counts cm(-2) day(-1) on 18 March 2005. Japanese cypress pollen dispersed in that area in the latter period was compared with the Japanese cedar pollen dispersions. The maximum dispersion level was observed to be 351 counts cm(-2) day(-1) on 7 April 2005. Total accumulated dispersions of Japanese cedar and Japanese cypress pollens were 5,552 and 1,552 counts cm(-2) for the three months (Feb., Mar. and Apr.) in 2005, respectively. However, the dispersion of both pollens in 2006 was very low. The total accumulated dispersions of Japanese cedar and Japanese cypress pollens were 421 and 98 counts cm(-2) for three months (Feb., Mar. and Apr.) in 2006, respectively. Moreover, the pollen deposition on a walking person in an urban area showed that the pollen counts on feet were observed to be extremely high compared with the ones on the shoulder, back and legs. These findings suggested that pollen fell on the surface of the paved road at first, rebounded to the ambient air and was deposited on the residents again. Furthermore, the regional distribution of the total pollen dispersion in the South Kanto area was characterized on 15-16 March 2005 and on 14-15 March 2006. Although the pollen levels in 2005 were much higher than in 2006, it was commonly observed that higher pollen counts existed in the outlying areas. That is, the pollen counts in an urban area were confirmed to be at a lower level. As for the indoor dispersion of pollens, two cases were evaluated. At the lobby of the main building of Kyoritsu Women's University, the averaged ratio of the indoor to the outdoor pollen count is 4.1%. Another case was at the hospital building of a medical school. The pollen dispersion in the indoor environment was also observed to be low. It was concluded that the indoor pollen would be mainly carried from the outer environment by the movement of air.

Identification of human T cell epitopes in Japanese cypress pollen allergen, Cha o 1, elucidates the intrinsic mechanism of cross-allergenicity between Cha o 1 and Cry j 1, the major allergen of Japanese cedar pollen, at the T cell level

BACKGROUND

Pollens from species of Cupressaceae family are one of the most important causes of respiratory allergies worldwide. In Japan, many patients with pollinosis have specific IgE to both pollens of Japanese cypress (Chamaecyparis obtusa) and Japanese cedar (Cryptomeria japonica). The sequences between Cha o 1 and Cry j 1, the major allergens of Japanese cypress and Japanese cedar pollens, respectively, are 80% identical.

OBJECTIVE

This study was undertaken to identify T cell epitopes in Cha o 1, and to elucidate the mechanism of cross-allergenicity between Cha o 1 and Cry j 1, at the T cell level.

METHODS

T cell epitopes in Cha o 1 were identified by the reactivity of T cell lines, generated from 19 patients, to stimulation with overlapping peptides. The subsets of T cell clones specific to rCha o 1 were determined according to their ability to produce IL-4 and IFN-gamma. Peptide specificities of two T cell clones were determined by stimulation with the peptides from Cha o 1 and Cry j 1.

RESULTS

Four dominant and six subdominant T cell epitopes were identified in Cha o 1. While four T cell epitopes, p11-30, p211-230, p251-270 and p331-350, were common to Cha o 1 and Cry j 1, 4 T cell epitopes, p61-80, p71-90, p311-330 and p321-340, were considered to be unique to Cha o 1. The subsets of T cell clones were predominantly of T helper2-type. One T cell clone recognized p16-30, which is common to Cha o 1 and Cry j 1, but another recognized p321-330, which is unique to Cha o 1.

CONCLUSION

Presence of both T cells reactive to T cell epitopes common to Cha o 1 and Cry j 1 and T cells specific to T cell epitopes unique to Cha o 1 in patients with pollinosis contributes to prolonged symptoms after the cedar pollen season in March and the following cypress pollen season in April.

Structural basis for epitope sharing between group 1 allergens of cedar pollen

The group 1 allergens are a major cause of cedar pollen hypersensitivity in several geographic areas. Allergens from several taxa have been shown to cross-react. The goal of these studies was to compare the structural features of the shared and unique epitopes of the group 1 allergen from mountain cedar (Jun a 1) and Japanese cedar (Cry j 1). An array of overlapping peptides from the sequence of Jun a 1 and a panel of monoclonal anti-Cry j 1 antibodies were used to identify the IgE epitopes recognized by cedar-sensitive patients from Texas and Japan. IgE from Japanese patients reacted with peptides representing one of the two linear epitopes within the highly conserved beta-helical core structure and both epitopes within less ordered loops and turns near the N- and C-termini of Jun a 1. A three-dimensional (3D) model of the Cry j 1, based on the crystal structure of Jun a 1, indicated a similar surface exposure for the four described epitopes of Jun a 1 and the homologous regions of Cry j 1. The monoclonal antibodies identified another shared epitope, which is most likely conformational and a unique Cry j 1 epitope that may be the previously recognized glycopeptide IgE epitope. Defining the structural basis for shared and unique epitopes will help to identify critical features of IgE epitopes that can be used to develop mimotopes or identify allergen homologues for vaccine development.

Allergy to cypress pollen

Although Cupressus sempervirens has been spread over southern Europe since antiquity, cypress pollen allergy has not been reported until 1945. In France, the very first case reports were published in 1962. Since then, the prevalence of cypress pollinosis seems to demonstrate an upward trend, concomitantly with the increased use of cypress trees as ornamental plants, as wind breaks and as hedges. Hyposensitization, using improved pollen extracts, is increasingly prescribed. Besides, prevention measures begin to be implemented. Such measures include avoidance of planting new cypress trees, especially near human populations' centres, trimming of cypress hedges before the pollination season and agronomical research for hypoallergenic trees. Altogether, such new developments in cypress allergy deserve an update review.

Biochemical and Immunological Characterization of Pollen-Derived β-Galactosidase Reveals a New Cross-Reactive Class of Allergens among Mediterranean Trees

BACKGROUND

The most potent allergens in the Spermatophytae family exhibit significant homology with enzymes. Some of these are though to be involved in pectin metabolism, recognition of compatible stigma and delivery of sperm cells to the ovule.

OBJECTIVE

To test if glycohydrolase activities from some Mediterranean tree pollens could act as allergens in sensitized hosts.

METHODS

Freshly collected Cupressus and Olea pollens were investigated for their glycohydrolase activities by means of synthetic fluorogenic substrates and isoenzymes characterized by DEAE-cellulose ion-exchange chromatography. Binding of specific IgE was investigated by immunoblotting in 30 tree-sensitive subjects, as well as in 20 atopic non-tree-sensitive and 15 healthy controls. The enzymes were also adopted to stimulate proliferation of allergen-specific T cell clones. Finally, they were tested in vivo in a cutaneous immediate wheal and flare reaction.

RESULTS

beta-Galactosidase (beta-GAL) is present with different isoenzymatic patterns on both pollen extracts, could be recognized by circulating IgE, as well as immunoprecipitated by sera from allergic subjects. The enzyme could stimulate the proliferation of T cells from allergic subjects, and favor the emergence of CD4+ T cell clones with specific in vitro reactivity to beta-GAL. Finally, the enzyme induced in vivo a cutaneous wheal and flare reaction in clinically sensitive subjects.

CONCLUSIONS

Despite different isoenzymatic patterns, Olea-derived beta-GAL cross-reacted with that from cypress pollen, suggesting that these enzymatic glycoproteins may represent major native allergens among these Mediterranean trees.

Crystal structure of Jun a 1, the major cedar pollen allergen from Juniperus ashei, reveals a parallel beta-helical core

Pollen from cedar and cypress trees is a major cause of seasonal hypersensitivity in humans in several regions of the Northern Hemisphere. We report the first crystal structure of a cedar allergen, Jun a 1, from the pollen of the mountain cedar Juniperus ashei (Cupressaceae). The core of the structure consists primarily of a parallel beta-helix, which is nearly identical to that found in the pectin/pectate lyases from several plant pathogenic microorganisms. Four IgE epitopes mapped to the surface of the protein are accessible to the solvent. The conserved vWiDH sequence is covered by the first 30 residues of the N terminus. The potential reactive arginine, analogous to the pectin/pectate lyase reaction site, is accessible to the solvent, but the substrate binding groove is blocked by a histidine-aspartate salt bridge, a glutamine, and an alpha-helix, all of which are unique to Jun a 1. These observations suggest that steric hindrance in Jun a 1 precludes enzyme activity. The overall results suggest that it is the structure of Jun a 1 that makes it a potent allergen.

Transition from a Botanical to a Molecular Classification in Tree Pollen Allergy: Implications for Diagnosis and Therapy

Tree pollens are among the most important allergen sources. Allergic cross-reactivity to pollens of trees from various plant orders has so far been classified according to botanical relationships. In this context, cross-reactivities to pollens of trees of the Fagales order (birch, alder, hazel, hornbeam, oak, chestnut), fruits and vegetables, between pollens of the Scrophulariales (olive, ash, plantain, privet, lilac) and pollens of the Coniferales (cedar, cypress, pine) are well established. The application of molecular biology methods for allergen characterization has revealed the molecular nature of many important tree pollen allergens. We review the spectrum of tree pollen allergens and propose a classification of tree pollen and related allergies based on major allergen molecules instead of botanical relationships among the allergenic sources. This molecular classification suggests the major birch pollen allergen, Bet v 1 as a marker for Fagales pollen and related plant food allergies, the major olive pollen allergen, Ole e 1, as a possible marker for Scrophulariales pollen allergy and the cedar allergens, Cry j 1 and Cry j 2, as potential markers for allergy to Coniferales pollens. We exemplify for Fagales pollen allergy and Bet v 1 that major marker allergens are diagnostic tools to determine the disease-eliciting allergen source. Information obtained by diagnostic testing with marker allergens will be important for the appropriate selection of patients for allergen-specific forms of therapy.

Refolding of the Cupressus arizonica major pollen allergen Cup a1.02 overexpressed in Escherichia coli

The cDNA encoding an isoform of the cypress major pollen allergen, Cup a1.02, has been cloned and expressed in Escherichia coli as a N-terminal 6x His-tagged protein. To increase recovery, Cup a1.02 was expressed at high levels exploiting the T5 strong promoter and led to accumulate as inclusion bodies. The insoluble purified aggregates were solubilized in 6 M guanidine hydrochloride, immobilized using nickel-chelating affinity chromatography, and successfully refolded by controlled removal of the chaotropic reagent. Enhanced protein refolding was observed by reducing the protein concentration at 0.6-0.8 mg/ml. SDS-PAGE and gel filtration chromatography indicated an apparent molecular mass of approximately 40 kDa and the occurrence of the protein as monomers. The reconstituted fusion protein displayed the same immunological properties of the native Cup a1.02 protein as proven by IgE immunoreactivity. Immunoblotting, ELISA, and histamine release test showed that the tag did not preclude the protein functionality hence validating its correct three-dimensional folding. The protein fold was also assessed by CD spectroscopy and deconvolution of the spectrum allowed to estimate the secondary structure as a prevalence of beta structures (higher than 60%) and a small contribution from alpha helices (less than 12%). The reported procedure has proven to be useful for the production of multi-milligrams of recombinant Cup a1.02 allergen suitable for structural biology studies and for the molecular and functional characterization of the IgE binding sites.

Cloning and expression of a major allergen from Cupressus arizonica pollen, Cup a 3, a PR-5 protein expressed under polluted environment

BACKGROUND

This paper describes the cloning and expression of the Cupressus arizonica pollen protein Cup a 3. In addition, we present its modulation under polluted environmental conditions. Species of the Cupressaceae family are important because of their high sensitization prevalence.

METHODS

Cup a 3 cloning is based on the sequence of the homologous protein Jun a 3. Cup a 3 was expressed with good yield in the methylotropic yeast Pichia pastoris.

RESULTS

Recombinant Cup a 3 (rCup a 3) contains 199 amino acids, 10 potential phosphorylation sites and no glycosylation sites. By immunoblot 63% of cypress allergic patients had specific immunoglobulin E antibodies against rCup a 3 (n = 104). This major allergen is homologous to members of the pathogenesis-related proteins (PR-5 group) and contributes to the overall allergenicity of C. arizonica pollen. Our results show that the increased expression of Cup a 3 is dependent on the pollution in the area where the pollen has been collected, being higher under polluted conditions.

CONCLUSIONS

Cup a 3 is a PR-5 protein derived from C. arizonica pollen. The expression of the protein under polluted conditions has a direct incidence on the pollen allergenicity, as has been demonstrated by skin tests and Radioallergosorbent test inhibition.

Major linear IgE epitopes of mountain cedar pollen allergen Jun a 1 map to the pectate lyase catalytic site

Resolution of the 3D structures and IgE epitopes of allergens may identify common or conserved features of allergens. Jun a 1, the predominant allergen in mountain cedar pollen, was chosen as a model for identifying common structural and functional features among a group of plant allergens. In this study, synthetic, overlapping peptides of Jun a 1 and sera from patients allergic to mountain cedar pollen were used to identify linear epitopes. A 3D model of Jun a 1 was produced using the Bacillus subtiles pectate lyase (PL) as a template and validated with biophysical measurements. This allowed mappings of four IgE binding sites on Jun a 1. Two of the epitopes mapped to turns or loops on the surface of the model structure. The other two epitopes mapped to the beta-sheet region, homologous to the catalytic site of PL. This region of Jun a 1 is highly conserved in the group 1 allergens from other cedar trees as well as microbial PLs. The finding that two out of three major IgE epitopes map to highly conserved catalytic regions of group 1 cedar allergens may help to explain the high degree of cross-reactivity between cedar pollen allergens and might represent a pattern of reactivity common to other allergens with catalytic activity.

Comparison between the native glycosylated and the recombinant Cup a1 allergen: role of carbohydrates in the histamine release from basophils

BACKGROUND

Cypress pollinosis is an important cause of respiratory allergies. Recently, the Cupressus arizonica major allergen, Cup a1, has been cloned and expressed. The native counterpart of this allergen has been purified and characterized by our group. It has been suggested that sugar moieties play a role in the in vitro IgE binding on Cupressus arizonica pollen extract.

OBJECTIVE

To characterize the immunoreactivity of the recombinant major allergen in comparison with its native counterpart. To evaluate the role of carbohydrate moieties in the IgE-mediated in vitro histamine release from basophils by using the native glycosylated Cup a1 as compared with the recombinant one.

METHODS

Recombinant Cup a1 was expressed in E. coli. IgE reactivity of Cupressaceae-allergic patients on the native as well as the recombinant molecule was investigated by immunoblotting, ELISA experiments and histamine release test from passively sensitized basophils.

RESULTS

Fourteen out of 17 Cup a1-positive sera had IgE antibodies reactive with the native molecule only and lost their reactivity-after periodate deglycosylation of the allergen. Moreover, only native molecule was capable of inducing histamine release by this group of sera. Both the recombinant and the native molecules were recognized by three out of the 17 sera and were equally capable of triggering degranulation.

CONCLUSION

A large number of sera reactive with the major allergen recognize carbohydrate epitopes only. IgE from these sera are able to induce histamine release from basophils and they might play a functional role in the clinical symptoms of allergy.

Can knowledge of the molecular structure of allergens improve immunotherapy?

Conventional immunotherapy may be associated with the development of adverse reactions, including anaphylaxis, due to the use of increasing doses of allergen. Standardization of extracts is necessary in order to assess the correct amount of allergen administered. In recent years, increased knowledge on the molecular structure of allergens has allowed the development of novel alternatives for immunotherapy. Initially, allergens were cloned and expressed as recombinant proteins in eukaryotic and prokaryotic systems. Crystallization of the purified proteins led to the elucidation of the tertiary structure of the allergen. Molecular biology techniques were used to construct modified allergens whose new IgE binding properties were studied. IgE antibody mapping combined with molecular modeling has allowed the recognition of IgE binding sites on the surface of the molecule. This information has been applied to the engineering of new modified allergens, with and without adjuvants, that retain immunogenicity but with reduced allergenicity. The use of these molecules for immunotherapy should allow the administration of greater doses of allergen, without the undesired side effects characteristic of conventional immunotherapy.

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.