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.

Peptide Glycodendrimers as Potential Vaccines for Olive Pollen Allergy.

Olive pollen is one of the most important causes of respiratory allergy, with Ole e 1 being the most clinically relevant sensitizing allergen. Peptide-based vaccines represent promising therapeutic approaches, but the use of adjuvants is required to strengthen the weak immunogenicity of small peptides. We propose the use of dendrimeric scaffolds conjugated to the T cell immunodominant epitope of Ole e 1 (OE109-130) for the development of novel vaccines against olive pollen allergy. Four dendrimeric scaffolds containing an ester/ether with nine mannoses, an ester succinimidyl linker with nine N-acetyl-glucosamine units or nine ethylene glycol units conjugated to OE109-130 peptide were designed, and their cytotoxicity, internalization pattern, and immunomodulatory properties were analyzed in vitro. None of the dendrimers exhibited cytotoxicity in humanized rat basophil (RBL-2H3), human bronchial epithelial Calu-3, and human mast LAD2 cell lines. Confocal images indicated that mannosylated glycodendropeptides exhibited lower colocalization with a lysosomal marker. Moreover, mannosylated glycodendropeptides showed higher transport tendency through the epithelial barrier formed by Calu-3 cells cultured at the air-liquid interface. Finally, mannosylated glycodendropeptides promoted Treg and IL10+Treg proliferation and IL-10 secretion by peripheral blood mononuclear cells from allergic patients. Mannosylated dendrimers conjugated with OE109-130 peptide from Ole e 1 have been identified as suitable candidates for the development of novel vaccines of olive pollen allergy.

Immunochemical and Physical Quantitation of Grass and Olive Pollen Allergens: Correlation With Asthma Admissions in Cáceres, Spain.

BACKGROUND AND OBJECTIVES: The association between pollen counts and allergen levels in the air is controversial. Objectives: The aims of the study were to quantify total and major allergen levels of Phleum pratense and Olea europaea and to analyze their correlation with grass and olive pollen counts and the number of asthma attacks attended at Complejo Hospitalario Universitario, Cáceres, Spain. MATERIAL AND METHODS: A volumetric air sampler and a Burkard spore trap were used for pollen and aeroallergen collection during April- June 2011. Filters were extracted, and major allergens were quantified using enzyme-linked immunosorbent assay. RESULTS: May was the main grass pollination period, with a maximum peak of 1362 grains/m3 (May 13). The main pollination period for olive was April 30-May 20, with a maximum peak of 851 grains/m3 (May 11). A moderate correlation was observed between asthma exacerbations and grass pollen counts or Phleum total allergen levels; this became stronger when a 3-day offset was introduced. A significant association was observed between asthma exacerbations and total olive allergen or olive pollen grain levels when a 1-day offset was introduced. The maximum correlation (moderate-high) was observed 4 days and 6 days away from the maximum olive pollen peak and the maximum Ole e 1 peak level, respectively. CONCLUSIONS: This study reveals a significant correlation between grass and olive pollination and an increase in the number of visits to the emergency room for asthma attacks. The aerobiological pattern of allergen levels in the air is similar to that of pollen counts during the grass and olive pollination periods.

Clinical assessment of tolerability, immunological and cutaneous reactivity effects of an abbreviated schedule with Olea europaeanative extract of subcutaneous immunotherapy.

Summary: Objectives. To evaluate the tolerability and efficacy of Olea europaea subcutaneous immunotherapy (SCIT) on patients with rhinoconjunctivitis. Methods. In this open clinical trial patients were assigned to an abbreviated build-up scheme. The outcomes were: number, percentage, and severity of adverse reactions. Secondary outcomes included: changes in immunoglobulin titers and changes in dose-response skin prick tests. Results. Only 8 systemic reactions were registered, which represented 7/47 (14.9%) of patients and 8/429 (1.9%) of administered doses. Regarding immunological parameters the significant increases of sIgG and sIgG4 evidenced the changes in the patient immune system. Cutaneous reactivity decreased significantly. Conclusions. Olea europaea SCIT (Allergovac® depot ROXALL Medicina España S.A.) showed a good safety and tolerability profile. Immunological changes with induction of blocking IgG and decreases in cutaneous reactivity were detected in the patients.

Peach Tree Pollen and Prunus persica 9 Sensitisation and Allergy in Children and Adolescents.

BACKGROUND: Although plant and fruit pollens are entomophilous and relevant in exposed workers, we have shown a high frequency of sensitisation and symptoms induction of peach tree pollen (PTP) and Prunus persica 9 (Pru p 9) in adults from areas of peach cultivars. METHODS: We studied the sensitisation and clinical relevance of PTP and Pru p 9 in a large group of children and adolescents aged 3-19 years. A detailed questionnaire plus skin prick testing to prevalent allergens, PTP, and Pru p 9 were carried out. The clinical relevance was established by nasal provocation test (NPT) and symptom score index. RESULTS: We evaluated 685 children (mean age 8.75 ± 3.3 years, median 9 years), 52% of them female. Sensitisation to PTP occurred in 20% of the cases following olive tree (33%) and Phleum pratense (26%). In a randomly selected subgroup of subjects sensitised to PTP, 30% were skin prick test-positive to Pru p 9. Most cases had rhinitis or rhinoconjunctivitis. NPT showed the relevance of PTP and Pru p 9 in the induction of symptoms. CONCLUSION: PTP and Pru p 9 are relevant in the induction of sensitisation and respiratory symptoms in children and adolescents. This allergen should be evaluated in children living in regions of peach tree cultivars.

Delineation of the Olive Pollen Proteome and Its Allergenome Unmasks Cyclophilin as a Relevant Cross-Reactive Allergen.

Olive pollen is a major allergenic source worldwide due to its extensive cultivation. We have combined available genomics data with a comprehensive proteomics approach to get the annotated olive tree (Olea europaea L.) pollen proteome and define its complex allergenome. A total of 1907 proteins were identified by LC-MS/MS using predicted protein sequences from its genome. Most proteins (60%) were predicted to possess catalytic activity and be involved in metabolic processes. In total, 203 proteins belonging to 47 allergen families were found in olive pollen. A peptidyl-prolyl cis-trans isomerase, cyclophilin, produced in Escherichia coli, was found as a new olive pollen allergen (Ole e 15). Most Ole e 15-sensitized patients were children (63%) and showed strong IgE recognition to the allergen. Ole e 15 shared high sequence identity with other plant, animal, and fungal cyclophilins and presented high IgE cross-reactivity with pollen, plant food, and animal extracts.

Tolerability and surrogate efficacy parameters of a polymerized depot mixture pollen extracts without dilutional effect.

Aim: To evaluate tolerability of subcutaneous immunotherapy, in a polymerized mixture (Olea europaea/Phleum pratense) depot presentation. Patients & methods: A total of 47 poly-allergic patients received: an abbreviated schedule with three injections at weekly intervals or a cluster schedule with two administrations in 1 day. Both treatments continued with 3 monthly maintenance administrations. Results: Two systemic reactions, (4.3%). One grade 0 and one grade I. No local reactions. Immunoglobulin levels, increased significantly at final visit versus baseline in sIgG and sIgG4; in both schedules and allergens, no significant changes in specific immunoglobulin E levels were detected. Cutaneous reactivity at final visit decreased significantly. Conclusion: Both administration schedules with polymerized mixture of O. europaea/P. pratense, presented an excellent tolerability profile and induced preliminary efficacy changes.

Detection of profilin in SPT extracts that are supposed to contain it.

INTRODUCTION AND OBJECTIVES: Profilin is a panallergen contained in pollen, plant foods and latex. Although cross-reactivity is expected while performing skin prick tests (SPT) with allergens that contain profilin, this is not always noticed. The purpose of this study was to detect if profilin is contained in the commercial SPT extracts of pollen and plant foods which, in their fresh form, contain determined epitopes of profilin. MATERIAL AND METHODS: Commercial SPT extracts of different pharmaceuticals were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The study included purified palm date profilin, peach (whole, pulp and peel extracts), hazelnut, Olea europea, Parietaria judaica and Phleum pratense. RESULTS: Profilin was detected in all, but peach extracts; it was neither contained in the whole peach extract nor in the ones of peel or pulp. CONCLUSION: The only accurate way to detect sensitization to profilin, while performing SPT, is the use of purified profilin extract. Even if a plant food or pollen contain an identified molecule of profilin, the relevant SPT commercial extract may not.

A Hypoallergenic Polygalacturonase Isoform from Olive Pollen Is Implicated in Pollen-Pollen Cross-Reactivity.

BACKGROUND: Cross-reactivity reactions between allergenic polygalacturonases (PGs) from different biological sources, especially foods and pollens from the Oleaceae family, have been described using Salsola kali PG (Sal k 6). No PG from olive pollen has been characterized to date, hampering further knowledge about cross-reactions through PGs. OBJECTIVES: The aim of this work was to determine the potential allergenicity of the PG from olive pollen and clarify its role in cross-reactivity. METHODS: A cDNA-encoding olive pollen PG sequence was subcloned into the pET41b vector and used to transform BL21(DE3) Escherichia coli cells to produce a His-tag fusion recombinant protein. The allergenic properties of olive pollen PG were determined by immunoblotting and ELISA in comparison to Sal k 6. The cross-reactivity potential of the protein with other pollen sources was analyzed by inhibition immunoassays. RESULTS: The existence of other isoforms of Ole e 14 with different allergenicity was confirmed by proteomics and a meta-analysis of the recently reported olive genome. Sal k 6 showed a higher IgE recognition than Ole e 14 regardless of patient sensitization, suggesting the existence of more allergenic Ole e 14 isoforms in olive pollen. IgG and IgE inhibition assays supported the existence of cross-reactions between them and with other PGs from Oleaceae and Poaceae plant families. CONCLUSIONS: A new allergen from olive pollen, Ole e 14, has been identified, produced as a recombinant isoform, and structurally and immunologically characterized. Its role in cross-reactivity has been confirmed and, due to its smaller IgE binding capacity, it could have an important role for therapeutic purposes.

Comparative study of adjuvants for allergen-specific immunotherapy in a murine model.

AIM: To compare the immunological and clinical changes induced by allergen-specific immunotherapy (AIT) using different adjuvants. MATERIALS & METHODS: Olea europaea pollen-sensitized mice were treated with olea plus aluminum hydroxide, calcium phosphate, monophosphoryl lipid A (MPL) or immunostimulatory sequences (ISS). RESULTS: Aluminum hydroxide seems to drive initially to a Th2-type response. Bacteria-derived adjuvants (MPL and ISS) skew the immune response toward Th1 and Treg pathways. Specific-IgE production was lower after AIT with MPL and ISS. Moreover, IgG2a production significantly increased in ISS-treated mice. Bacteria-derived adjuvants also improved the Th1 cytokine response due to IFN-γ higher secretion. In addition, they improved bronchial hyper-reactivity and lung inflammation. CONCLUSION: Bacteria-derived adjuvants may enhance the efficacy of AIT.

A recombinant isoform of the Ole e 7 olive pollen allergen assembled by de novo mass spectrometry retains the allergenic ability of the natural allergen.

The allergenic non-specific lipid transfer protein Ole e 7 from olive pollen is a major allergen associated with severe symptoms in areas with high olive pollen levels. Despite its clinical importance, its cloning and recombinant production has been unable by classical approaches. This study aimed at determining by mass-spectrometry based proteomics its complete amino acid sequence for its subsequent expression and characterization. To this end, the natural protein was in-2D-gel tryptic digested, and CID and HCD fragmentation spectra obtained by nLC-MS/MS analyzed using PEAKS software. Thirteen out of the 457 de novo sequenced peptides obtained allowed assembling its full-length amino acid sequence. Then, Ole e 7-encoding cDNA was synthesized and cloned in pPICZαA vector for its expression in Pichia pastoris yeast. The analyses by Circular Dichroism, and WB, ELISA and cell-based tests using sera and blood from olive pollen-sensitized patients showed that rOle e 7 mostly retained the structural, allergenic and antigenic properties of the natural allergen. In summary, rOle e 7 allergen assembled by de novo peptide sequencing by MS behaved immunologically similar to the natural allergen scarcely isolated from pollen. SIGNIFICANCE: Olive pollen is an important cause of allergy. The non-specific lipid binding protein Ole e 7 is a major allergen with a high incidence and a phenotype associated to severe clinical symptoms. Despite its relevance, its cloning and recombinant expression has been unable by classical techniques. Here, we have inferred the primary amino acid sequence of Ole e 7 by mass-spectrometry. We separated Ole e 7 isolated from pollen by 2DE. After in-gel digestion with trypsin and a direct analysis by nLC-MS/MS in an LTQ-Orbitrap Velos, we got the complete de novo sequenced peptides repertoire that allowed the assembling of the primary sequence of Ole e 7. After its protein expression, purification to homogeneity, and structural and immunological characterization using sera from olive pollen allergic patients and cell-based assays, we observed that the recombinant allergen retained the antigenic and allergenic properties of the natural allergen. Collectively, we show that the recombinant protein assembled by proteomics would be suitable for a better in vitro diagnosis of olive pollen allergic patients.

Molecular sensitization patterns and influence of molecular diagnosis in immunotherapy prescription in children sensitized to both grass and olive pollen.

BACKGROUND: The overlapping grass and olive pollen seasons in Spain and the phenomenon of cross-reactivity can make it difficult to determine the true causative agent of seasonal allergic rhinitis when only skin prick tests with whole extracts are used. The aim of the GRAMOLE study was to determine sensitization patterns to the major grass and olive pollen allergens detected using specific recombinant IgE and to explore how this knowledge affected physicians' choice of allergen-specific immunotherapy. METHODS: Epidemiological, observational, multicenter, cross-sectional study. Results from children under 18 years of age diagnosed with seasonal allergic rhinitis by positive skin prick tests to olive and grass pollen were analyzed. Specific IgE to Phl p 1+5, Ole e 1, and Phl p 7+12 was determined. Investigators specified the optimal composition of allergen immunotherapy before and after knowing the results of the molecular diagnosis. RESULTS: A total of 281 patients with a mean age of 13.4 years were included. Double sensitization to both major allergens was found in vitro in 76% of children for an IgE cutoff point of 0.35 kU/L. When the molecular diagnosis results were known, specialists changed the composition of the prescribed immunotherapy in 52.87% of cases. CONCLUSIONS: Double sensitization to grass and olive pollen is common in Spain and also occurs in the pediatric population. Molecular diagnosis using specific IgE may help improve immunotherapy selection in polysensitized patients.

Human Invariant Natural Killer T Cells Respond to Antigen-Presenting Cells Exposed to Lipids from Olea europaea Pollen.

BACKGROUND: Allergic sensitization might be influenced by the lipids present in allergens, which can be recognized by natural killer T (NKT) cells on antigen-presenting cells (APCs). The aim of this study was to analyze the effect of olive pollen lipids in human APCs, including monocytes as well as monocyte-derived macrophages (Mϕ) and dendritic cells (DCs). METHODS: Lipids were extracted from olive (Olea europaea) pollen grains. Invariant (i)NKT cells, monocytes, Mϕ, and DCs were obtained from buffy coats of healthy blood donors, and their cell phenotype was determined by flow cytometry. iNKT cytotoxicity was measured using a lactate dehydrogenase assay. Gene expression of CD1A and CD1D was performed by RT-PCR, and the production of IL-6, IL-10, IL-12, and TNF-α cytokines by monocytes, Mϕ, and DCs was measured by ELISA. RESULTS: Our results showed that monocytes and monocyte-derived Mϕ treated with olive pollen lipids strongly activate iNKT cells. We observed several phenotypic modifications in the APCs upon exposure to pollen-derived lipids. Both Mϕ and monocytes treated with olive pollen lipids showed an increase in CD1D gene expression, whereas upregulation of cell surface CD1d protein occurred only in Mϕ. Furthermore, DCs differentiated in the presence of human serum enhance their surface CD1d expression when exposed to olive pollen lipids. Finally, olive pollen lipids were able to stimulate the production of IL-6 but downregulated the production of lipopolysaccharide- induced IL-10 by Mϕ. CONCLUSIONS: Olive pollen lipids alter the phenotype of monocytes, Mϕ, and DCs, resulting in the activation of NKT cells, which have the potential to influence allergic immune responses.

Comparison of two diagnostic techniques, skin-prick test and component resolved diagnosis in the follow-up of a cohort of paediatric patients with pollinosis. Multicentre pilot study in a highly exposed allergenic area.

BACKGROUND: Over the last years, different works have been published about the importance of incorporating new diagnosis techniques in allergic patients such as component-resolved diagnosis (CRD). The objective of this study is to compare the evolution of allergic sensitisation profiles by means of CRD and cutaneous tests (SPT) on pollen-allergic patients. METHODS: A total of 123 patients aged between 2 and 14 years were included in an open, prospective, multicentre study. All the children had symptoms suggestive of seasonal respiratory allergic disease, with the diagnosis confirmed by cutaneous tests. Specific-IgE to major pollen-allergens (CRD) and SPT were performed at basal and after three years of follow-up. RESULTS: Out of 123 patients included, a total of 85 were analysed. The mean age was 8±3 years. Significant changes in the allergic sensitisation profiles were observed for the most prevalent allergens (Olea and grass) but it is in grass, the most relevant allergen in terms of allergen pressure, where changes in both absolute and relative frequencies between SPT and CRD were more evident. CONCLUSION: CRD seems to be an essential tool to carry out an appropriate follow-up of patients with allergic respiratory disease, as well as to decide on the immunotherapy composition that best matches the allergic sensitisation profile of patients.

Allergic sensitization prevalence in a children and adolescent population of northeastern Greece region.

OBJECTIVES: To evaluate the prevalence of allergic sensitization in a childhood and adolescent population, to explore age- and gender-specific variations and finally to discover co-sensitivities among allergens. METHODS: A two-stage cross-sectional survey among school-aged children. The two stages of the study involved enrollment of schools and then skin prick testing (SPT) within schools. A total of 675 school children were included in the study. Of those, 231 were diagnosed with allergic rhinitis (AR), according to the medical history as provided by parental-completed questionnaires and positive SPT results. The antigen panel consisted of common allergens and more specifically house dust mites-HDM (Dermatophagoides farinae and Dermatophagoides pteronyssinus), grass mix, trees (olive, cypress and pine), weeds (Parietaria spp.), cat and dog epithelium and moulds (Alternaria spp., Cladosporium spp.). The SPT sensitivity was graded according to SPT-USA Standards. RESULTS: The overall prevalence rate of AR was 34.22%. In total, 93 school children (40.3%) were mono- and 138 (59.7%) were poly-sensitized. Overall, the most prevalent sensitizations in decreasing order were to HDM (59.74%), to grasses (48.9%), to Alternaria (34.6%) and to olive (14.71%). There were no age- and sex-specific differences, except for Alternaria mould that showed a significant prevalence among primary school-aged children and predominance in the female gender, by contrast to grass pollen allergy that was predominant to males. A 32% of SPT-positive individuals were not aware of their allergy, with no statistically significant differences between ages. Co-sensitivities were detected for grass pollens and pine and olive trees, for Alternaria and Cladosporium moulds, for cypress and pine trees, and finally for dog and cat danders. CONCLUSIONS: Given data among school-aged children should be a baseline from which to monitor disease trends and is considered important for the optimal management of AR patients.

Potential health risk of allergenic pollen with climate change associated spreading capacity: Ragweed and olive sensitization in two German federal states.

BACKGROUND: Global climate changes may influence the geographical spread of allergenic plants thus causing new allergen challenges. OBJECTIVE: Allergy patients from two German federal states were compared for their status quo sensitization to ragweed, an establishing allergen, olive, a non-established allergen, and the native allergens birch, mugwort, and ash. METHODS: Between 2011 and 2013, 476 adult allergy patients per region were recruited. Patients completed a questionnaire, participated in a medical interview, and underwent skin prick testing and blood withdrawal for analysis of specific IgE to allergen components (ISAC technology). Data on regional pollen load from 2006 to 2011 were acquired from the German Pollen Information Service Foundation. RESULTS: Prick test reactivity to ragweed and ash, respectively, was lower in Bavaria than in NRW (ragweed: p=0.001, aOR=0.54; ash: p=0.001, aOR=0.59), whereas prick test reactivity to olive was higher (p=0.000, aOR=3.09). Prick test reactivity to birch and mugwort, respectively, did not significantly differ. 1% (1/127) of patients with prick test reactivity to ragweed showed sIgE to Amb a 1, and 65% (86/132) of olive-but-not-ash reactive patients showed sIgE to Ole e 1 (NRW: 67%, Bavaria: 65%; p=0.823, OR=0.91). Regional differences in sensitization pattern were neither explainable by cross-reactivity to pollen pan-allergens nor non-exposure variables nor by reported plant population or pollen data. CONCLUSIONS: Spread of ragweed and particularly olive may result in prompt occurrence of allergic symptoms. Early identification of invasive allergens due to climate change does need time and spatial close meshed measurement of respective indicator allergens and sensitization pattern.

Pollensomes as Natural Vehicles for Pollen Allergens.

Olive (Olea europaea) pollen constitutes one of the most important allergen sources in the Mediterranean countries and some areas of the United States, South Africa, and Australia. Recently, we provided evidence that olive pollen releases nanovesicles of respirable size, named generically pollensomes, during in vitro germination. Olive pollensomes contain allergens, such as Ole e 1, Ole e 11, and Ole e 12, suggesting a possible role in allergy. The aim of this study was to assess the contribution of pollensomes to the allergic reaction. We show that pollensomes exhibit allergenic activity in terms of patients' IgE-binding capacity, human basophil activation, and positive skin reaction in sensitized patients. Furthermore, allergen-containing pollensomes have been isolated from three clinically relevant nonphylogenetically related species: birch (Betula verrucosa), pine (Pinus sylvestris), and ryegrass (Lolium perenne). Most interesting, pollensomes were isolated from aerobiological samples collected with an eight-stage cascade impactor collector, indicating that pollensomes secretion is a naturally occurring phenomenon. Our findings indicate that pollensomes may represent widespread vehicles for pollen allergens, with potential implications in the allergic reaction.