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Olive Pollen

t224 Ole e 1

Biological Function Germination, tube growth, and/or pollen hydration
Code t224
IUIS Code 454
Route of Exposure Inhalation
Source Material Olive tree pollen allergen component
Latin Name Olea europaea
Other Names Common olive group 1
Categories Tree Pollens

Summary

Ole e 1, a group I allergen, is the most abundant in olive pollen. Olive pollen allergy is the most frequent allergy affecting people in the Mediterranean region. Ole e 1 has a sensitization frequency of 70% to more than 80% in patients allergic to Olive pollens. Exposure to Olive pollens triggers conjunctival and nasal symptoms in sensitized individuals. It may also exacerbate asthma in these patients, particularly when the olive pollen counts are high. The pollination season for olive ranges from mid-April to June end.

Ole e 1 is a glycoprotein composed of 145 amino acids. It shows widespread cross-reactivity with the main allergens of other genera from the Oleaceae family, including ash, privet, and lilac, due to the high degree of sequence homology between them. The cross-reactivity between Ole e 1 and ash is so high that Ole e 1 has been established to be a marker allergen for diagnosing allergy against the European ash pollen.

Allergen-specific immunotherapy (AIT) has been proved to be the only treatment that can effectively alter the disease course in pollen allergic patients. IgE testing for Ole e 1 has proved to be useful in the diagnostic workup for olive AIT. Since the period of pollination of Olive differs according to climate and geography, changes in the climate and sensitization spectrum of an individual must be recognized so that the exposure to pollens can be prevented as the patient may avoid visiting areas with Olive trees. 

Epidemiology

Worldwide distribution

Pollen from an Olive tree is the most significant allergy-causing pollen in the region of the Mediterranean basin (1-5). The prevalence of sensitization to Ole e 1 is very high, nearly 80% in Olive-pollen allergic individuals since it is the major protein in the Olive pollen (6, 7). Out of 891 pollen-sensitized patients in areas with high exposure to olive pollens in Spain, 75.3% were found to be sensitized to Ole e 1 (8). In Zurich (Switzerland), 181 out of 183 pollen-allergic patients in the age range of 7-76 years exhibiting typical allergic symptoms (rhinitis, conjunctivitis, and/or asthma) were found to be sensitized to Ole e 1 (9). Among 35 summer or spring pollinosis patients (sera samples) in Strasbourg, France, 60% of the patients were found to be sensitized to Ole e 1 (10).

Environmental Characteristics

Source and tissue

Ole e 1 is an allergen derived from pollens of the olive tree (0. europaea). It is the major allergen out of all the allergenic molecules of olive (11, 12), with a prevalence of 55-90 % (13).

Ole e 1 is explicitly found in the cisternae of the rough endoplasmic reticulum (RER) (14). It is synthesized and stored in the endoplasmic reticulum of the pollen grain (15).

The recombinant olive pollen allergens have been expressed using two different heterologous systems, Escherichia coli (prokaryotic host) and Pichia pastoris (P. pastoris), the methylotrophic yeast (as a eukaryotic system) (13).

Initially, Ole e 1 was expressed in E. coli in the form of a fusion protein associated with the glutathione S-transferase (13,21).  Ole e 1 has also been produced in P. pastoris, as well-folded cys-containing proteins (17).

Risk factors

Ole e 1 has a sensitization prevalence ranging from 70% to more than 80% amongst patients sensitive to olive pollen (7, 13). There is a great variation in the pollination period of Olea, depending on the geographical location. The pollination period for Olive pollens is between Mid-April and June-end in Spain and Italy, respectively (6). During the pollination period, there is an increase in the number of allergic individuals and individuals with severe symptoms due to the rise in pollen production (6).

Clinical Relevance

Specific molecules

Ole e 1, a group 1 allergen, is a part of the protein family associated with pollen germination, tube growth, and/or pollen hydration (13).

Ole e 1 is a polymorphic protein, representing nearly 20% of the entire protein content in Olive pollen extracts (13, 16). Ole e 1 has a major impact on the total allergenicity of the olive pollen (17).

The recombinant form of Ole e 1 (r Ole e 1) is as efficient as the natural Ole e 1 (n ole e 1) allergen molecule in diagnosing olive pollinosis (13).

Cross-reactive molecules

The comparable folding and/or glycosylation patterns account for the cross-reactivity of Ole e 1, not only with Ole e 1-like protein from allergenic species of Oleaceae, but also with other members of the Caryophyllales (i.e., Chenopodium album), Lamiales (i.e., Plantago lanceolata), or Poales (i.e., Lollium perenne or Phleum pratense) although to a lesser extent (7). Other genera of the Oleaceae family such as Lig v 1 (privet), Fra e 1 (ash), and Syr v 1(lilac) possess several Ole e 1 homologs. These are accountable for the high degree of IgE cross-reactivity among different species of Oleaceae plants (18-20).  Ole e 1-specific IgE in the serum of patients sensitized to Olive pollens inhibits cross-reactivity of pollens from Oleaceae family with non-Oleaceae families (21). Also, the similarity in the sequence of amino acids is very low (30–44%) between Ole e 1 and non-Oleaceae homologs. Thus, the cross-reactivity appears to be very low despite the presence of Ole e 1-homologous proteins in non-Oleaceae plants (e.g., grasses, plantain, and Chenopodium) pollens (20).

Molecular Aspects

Biochemistry

Ole e 1 is a glycoprotein made up of 145 amino acids (7). It occurs in glycosylated and nonglycosylated forms. Based on the carbohydrates present, the apparent molecular weight of Ole e 1 ranges between 18 kDa (nonglycosylated) and 20 kDa (glycosylated) (16, 19). Other forms, such as 22-kDa (hyperglycosylated) and 40-kDa (dimers of the glycosylated forms), also appear in the protein preparations occasionally (13, 15).

rOle e 1 exhibits differing degrees of glycosylation (12). The site for N-glycosylation is positioned at residue Asn111. As per the circular dichroism analyses, Ole e 1 comprises 22% a-helices, 38% β-structures, and 40% turns or random conformations. Antibody recognition requires both, glycosylation and an intact structure (7).

The spectroscopic properties (fluorescence and CD) and immunological reactivities (binding of IgG to the monoclonal antibodies that are sensitive to denaturation and IgE from sera of allergic patients) of r Ole e 1 are identical to those of the n Ole e 1 (12). 

Isoforms, epitopes, antibodies

Mapping of the B-cell antigenic determinants of Ole e 1 revealed seven overlapping IgG epitopes. Nearly all the epitopes presented a conformational character since the ability to bind to the IgG antibodies is lost after SDS-treatment and/or there is a reduction of the disulfide bridges of the Ole e 1 allergen (13).

At least 4 B-cell epitopes and 2 immunodominant T-cell epitopes in regions, aa 91 to 102, and aa 119 to 130 are found. This region is primarily recognized by patients allergic to olive pollen and induces a T cell-proliferative response lacking IgE-binding capability (22).

An IgE epitope is found in the isolated glycan; it is identified in more than 60% of the sera from Ole e 1 allergic patients (23).

The major binding protein in olive is Ole e 1. Most of the allergenic epitopes of olive pollen are present in Ole e 1 (19). It has an IgE-binding frequency of nearly 80% amongst olive pollinosis patients (7, 16, 17). The disulfide bond integrity determines the IgE recognition of Ole e 1 (20).

Cross-reactivity

The degree of allergenic cross-reactivity essentially depends on the similarity between the structure of the two allergens. Hence, cross-reactivity is frequently seen between homologous proteins  (23). The sequence of amino acids in Ole e 1 exhibits homology (24–34%) to proteins of the pollens from tomato, maize, rice, ryegrass, and birch (15). Similarly, Ole e 1 presents high levels of sequence homology and IgE cross-reactivity to other genera's major allergens from the Oleaceae-family, including ash, lilac, and privet (22, 24).

Widespread cross-reactivity is seen between Olive and ash to the extent that Ole e 1 works as a very good marker allergen for diagnosing allergy against ash pollen (9, 25).

Olive also presents cross-reactivity with Privet pine, Birch, Mugwort, and Cypress (26).

Diagnostic Relevance

Disease Severity

Ole e 1 sensitization signifies primary sensitization to Oleaceae pollens (21). The concentration of Olive allergen and pollen counts in the air is directly proportional to rhinitis and asthma symptoms in patients allergic to olive (27).

Ole e 1 is considered a marker allergen for diagnosing allergy to olive and ash pollen (9, 28).

AIT Prescription

An in vitro analysis conducted on 19 (13 asthmatic and six non-asthmatic) untreated patients who were allergic to olive pollen and ten healthy individuals who were not allergic to olive pollens revealed that Ole e 1 peptides induced an IL-35 and IL-10 mediated regulatory response, thus preventing the proliferation of olive pollens in the allergic patients. This shows that Ole e 1 peptides serve as potential therapeutic tools for preventing respiratory disorders caused by olive pollens (22).

Exposure

A patient’s sensitization profile is affected by the exposure to olive pollen (29). During the pollen season, the prevalence of pollinosis is high. In nearly 80% of olive-allergic patients, Ole e 1 has been identified (22). 

Compiled By

Author: Turacoz Healthcare Solutions

Reviewer: Dr. Magnus Borres

 

Last reviewed: November 2020

References
  1. Fernandez-Gonzalez M, Gonzalez-Fernandez E, Fernandez-Gonzalez D, Rodriguez-Rajo FJ. Secondary Outcomes of the Ole e 1 Proteins Involved in Pollen Tube Development: Impact on Allergies. Front Plant Sci. 2020;11:974.
  2. Castro L, Crespo JF, Rodriguez J, Rodriguez R, Villalba M. Immunoproteomic tools are used to identify masked allergens: Ole e 12, an allergenic isoflavone reductase from olive (Olea europaea) pollen. Biochim Biophys Acta. 2015;1854(12):1871-80.
  3. Hoflich C, Balakirski G, Hajdu Z, Baron JM, Kaiser L, Czaja K, et al. Potential health risk of allergenic pollen with climate change associated spreading capacity: Ragweed and olive sensitization in two German federal states. Int J Hyg Environ Health. 2016;219(3):252-60.
  4. Campo P, Villalba M, Barrionuevo E, Rondon C, Salas M, Galindo L, et al. Immunologic responses to the major allergen of Olea europaea in local and systemic allergic rhinitis subjects. Clin Exp Allergy. 2015;45(11):1703-12.
  5. Rojo J, Rapp A, Lara B, Sabariego S, Fernandez-Gonzalez F, Perez-Badia R. Characterisation of the airborne pollen spectrum in Guadalajara (central Spain) and estimation of the potential allergy risk. Environ Monit Assess. 2016;188(3):130.
  6. Villalba M, Rodriguez R, Batanero E. The spectrum of olive pollen allergens. From structures to diagnosis and treatment. Methods. 2014;66(1):44-54.
  7. Asam C, Hofer H, Wolf M, Aglas L, Wallner M. Tree pollen allergens-an update from a molecular perspective. Allergy. 2015;70(10):1201-11.
  8. Barber D, de la Torre F, Feo F, Florido F, Guardia P, Moreno C, et al. Understanding patient sensitization profiles in complex pollen areas: a molecular epidemiological study. Allergy. 2008;63(11):1550-8.
  9. Imhof K, Probst E, Seifert B, Regenass S, Schmid-Grendelmeier P. Ash pollen allergy: reliable detection of sensitization on the basis of IgE to Ole e 1. Allergo J Int. 2014;23(3):78-83.
  10. Stemeseder T, Metz-Favre C, de Blay F, Pauli G, Gadermaier G. Do Plantago lanceolata Skin Prick Test-Positive Patients Display IgE to Genuine Plantain Pollen Allergens? Investigation of Pollen Allergic Patients from the North-East of France. Int Arch Allergy Immunol. 2018;177(2):97-106.
  11. Villalba M, Batanero E, Lopez-Otin C, Sanchez LM, Monsalve RI, Gonzalez de la Pena MA, et al. The amino acid sequence of Ole e I, the major allergen from olive tree (Olea europaea) pollen. Eur J Biochem. 1993;216(3):863-9.
  12. Huecas S, Villalba M, Gonzalez E, Martinez-Ruiz A, Rodriguez R. Production and detailed characterization of biologically active olive pollen allergen Ole e 1 secreted by the yeast Pichia pastoris. Eur J Biochem. 1999;261(2):539-46.
  13. Rodriguez R, Villalba M, Batanero E, Gonzalez EM, Monsalve RI, Huecas S, et al. Allergenic diversity of the olive pollen. Allergy. 2002;57 Suppl 71:6-16.
  14. de Dios Alche J, Castro AJ, Olmedilla A, Fernandez MC, Rodriguez R, Villalba M, et al. The major olive pollen allergen (Ole e I) shows both gametophytic and sporophytic expression during anther development, and its synthesis and storage takes place in the RER. J Cell Sci. 1999;112 ( Pt 15):2501-9.
  15. Alché JdD, M’rani-Alaoui M, Castro AJ, Rodríguez-García MI. Ole e 1, the Major Allergen from Olive (Olea europaea L.) Pollen, Increases its Expression and is Released to the Culture Medium during in vitro Germination. Plant and Cell Physiology. 2004;45(9):1149-57.
  16. Arilla MC, Eraso E, Ibarrola I, Algorta J, Martinez A, Asturias JA. Monoclonal antibody-based method for measuring olive pollen major allergen Ole e 1. Ann Allergy Asthma Immunol. 2002;89(1):83-9.
  17. Quiralte J, Palacios L, Rodriguez R, Cardaba B, Arias de Saavedra JM, Villalba M, et al. Modelling diseases: the allergens of Olea europaea pollen. J Investig Allergol Clin Immunol. 2007;17 Suppl 1:24-30.
  18. Castro AJ, Alche JD, Calabozo B, Rodriguez-Garcia MI, Polo F. Pla 1 1 and Ole e 1 pollen allergens share common epitopes and similar ultrastructural localization. J Investig Allergol Clin Immunol. 2007;17 Suppl 1:41-7.
  19. Twaroch TE, Focke M, Civaj V, Weber M, Balic N, Mari A, et al. Carrier-bound, nonallergenic Ole e 1 peptides for vaccination against olive pollen allergy. J Allergy Clin Immunol. 2011;128(1):178-84 e7.
  20. Vara A, Fernandez-Gonzalez M, Aira MJ, Rodriguez-Rajo FJ. Oleaceae cross-reactions as potential pollinosis cause in urban areas. Sci Total Environ. 2016;542(Pt A):435-40.
  21. Rodriguez R, Villalba M, Batanero E, Palomares O, Quiralte J, Salamanca G, et al. Olive pollen recombinant allergens: value in diagnosis and immunotherapy. J Investig Allergol Clin Immunol. 2007;17 Suppl 1:4-10.
  22. Calzada D, Cremades-Jimeno L, Pedro MÁd, Baos S, Rial M, Sastre J, et al. Therapeutic potential of peptides from Ole e 1 in olive-pollen allergy. Scientific Reports. 2019;9(1):15942.
  23. Rodriguez R, Villalba M, Monsalve RI, Batanero E. The spectrum of olive pollen allergens. Int Arch Allergy Immunol. 2001;125(3):185-95.
  24. Robledo-Retana T, Mani BM, Teran LM. Ligustrum pollen: New insights into allergic disease. World Allergy Organ J. 2020;13(2):100104.
  25. Pablos I, Wildner S, Asam C, Wallner M, Gadermaier G. Pollen Allergens for Molecular Diagnosis. Current Allergy and Asthma Reports. 2016;16(4):31.
  26. Gibbs JE. Eucalyptus pollen allergy and asthma in children: a cross-sectional study in South-East Queensland, Australia. PLoS One. 2015;10(5):e0126506.
  27. Brito FF, Gimeno PM, Carnes J, Martin R, Fernandez-Caldas E, Lara P, et al. Olea europaea pollen counts and aeroallergen levels predict clinical symptoms in patients allergic to olive pollen. Ann Allergy Asthma Immunol. 2011;106(2):146-52.
  28. Palomares O, Swoboda I, Villalba M, Balic N, Spitzauer S, Rodriguez R, et al. The major allergen of olive pollen Ole e 1 is a diagnostic marker for sensitization to Oleaceae. Int Arch Allergy Immunol. 2006;141(2):110-8.
  29. Hauser M, Roulias A, Ferreira F, Egger M. Panallergens and their impact on the allergic patient. Allergy Asthma Clin Immunol. 2010;6(1):1.
  30. Quiralte J, Gonzalez E, Arias De Saavedra JM, Villalba M, Florido JF, Saenz De San Pedro B, et al. Immunological activity of recombinant Ole e 1 in patients with Olea europaea pollinosis. Int Arch Allergy Immunol. 2000;122(2):101-7.