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Weed pollen allergens
Published in Richard F. Lockey, Dennis K. Ledford, Allergens and Allergen Immunotherapy, 2020
Michael Hauser, Gabriele Gadermaier, Sabrina Wildner, Lisa Pointner, Michael Wallner, Fatima Ferreira
Skin prick testing with allergen extracts allows clinicians to identify sensitivity to a given pollen. But extract-based allergy diagnosis of weed pollen is often difficult due to multisensitization of patients, overlapping flowering seasons, and similar allergen profiles [87]. However, component-resolved diagnosis offers the possibility to study IgE reactivity to individual allergens. Correctly confirming the diagnosis of ragweed and mugwort pollen allergy represents a major clinical problem in areas where both plants are endemic. Discrimination between cosensitization and cross-reactivity is essential for decision-making regarding allergen immunotherapy. Sensitization to both commonly occurs; however, ragweed Amb a 1 belongs to the pectate lyase family, whereas mugwort Art v 1 represents a defensin-like glycoprotein belonging to the pathogenesis-related protein family 12 (PR-12) [4,47]. Although ragweed Amb a 4 and mugwort Art v 6 are minor allergens, they are homologous to the major allergens, Art v 1 and Amb a 1, respectively. In addition, the cross-reactive pan-allergens, profilins, and nsLTPs, as well as polcalcins present in both pollens hamper the accurate diagnosis when using pollen extracts. However, the pan-allergens are only to a minor extent accountable for the cross-reactivity of IgE antibodies [4,15].
Weed Pollen Allergens
Published in Richard F. Lockey, Dennis K. Ledford, Allergens and Allergen Immunotherapy, 2014
Fátima Ferreira, Gabriele Gadermaier, Michael Hauser, Michael Wallner
Skin prick testing with allergen extracts allows clinicians to identify sensitivity to given pollen but not to individual allergens. However, component-resolved diagnosis offers the possibility to study IgE reactivities to individual allergens. Correctly confirming the diagnosis of ragweed and mugwort pollen allergy represents a major clinical problem in areas where both plants are endemic. Sensitization to both commonly occurs; however, ragweed Amb a 1 belongs to the pectate lyase family, whereas mugwort Art v 1 represents a defensin-like glycoprotein belonging to the pathogenesis-related protein family 12 (PR-12) [2,26]. Although ragweed Amb a 4 and mugwort Art v 6 are minor allergens, they are homologous to the major allergens, Art v 1 and Amb a 1, respectively. In addition, the highly cross-reactive pan-allergens, pro-filins, and nsLTPs as well as Ca2+-binding allergens, present in both pollen hampers the accurate diagnosis when using pollen extracts.
Peanut Allergy Biomolecular Characterization for Development of a Peanut T-Cell Epitope Peptide Therapy
Published in Andreas L. Lopata, Food Allergy, 2017
Jennifer M. Rolland, Sara R. Prickett, Robyn E. O’Hehir
To date, 17 peanut allergens have been identified (Ara h 1-17; WHO/International Union of Immunological Societies Allergen Nomenclature Subcommittee, http: / / http://www.allergen.org/; cited 2015; summarized in Table 12.1). The allergens belong to several different biochemical families, but several are seed storage proteins. Ara h 1 and Ara h 2 are cupin and conglutin family members, respectively and are designated major peanut allergens, each being recognized by serum IgE in > 50% of peanut allergic cohorts tested (Burks et al. 1995, Kleber-Janke 1999). Together these two allergens constitute ~ 25% of total peanut protein. Although Ara h 3 is reported by some as a major allergen, serum IgE recognition has been inconsistent between cohorts with others reporting < 50% responders (e.g., Rabjohn et al. 1999). In contrast, Ara h 6 is classified a minor allergen, but many reports support its reclassification as a major allergen, which may be attributed to the high degree of sequence homology with Ara h 2 (Kleber-Janke et al. 1999). Ara h 8 is a major allergen in patients with combined birch pollen and peanut allergy as it shows homology to Bet v 1; both are members of the pathogenesis-related protein (PR10) family (Mittag et al. 2004). Ara h 1 is the most abundant major peanut allergen comprising 12-16% of total peanut protein (Koppelman et al. 2001, de Leon et al. 2007) while several studies have confirmed that Ara h 2 is the most potent peanut allergen (Blanc et al. 2009, Koppelman et al. 2004, Palmer et al. 2005). There is consensus that both Ara h 1 and Ara h 2 are important in clinical peanut allergy and would need to be considered in a novel therapy. The two allergens have been cloned and sequenced (Burks et al., 1995, Chatel et al. 2003) facilitating molecular characterization and design of a composite therapeutic.
Production of bioactive recombinant ovine cysteine-rich secretory protein 1 in Escherichia coli
Published in Systems Biology in Reproductive Medicine, 2021
Kalpana Jorasia, Rajani Kr. Paul, N. S. Rathore, Pyare Lal, R. Singh, Meenaxi Sareen
Cysteine-rich secretory proteins (CRISPs) are a subgroup of CRISP, antigen 5, pathogenesis-related protein 1 (CAP) super-family, characterized by the presence of N-terminal CAP domain (21 kDa) that contains six conserved cysteine residues, and the C-terminal CRISP domain (6 kDa) that contains 10 conserved cysteine residues (Gibbs et al. 2008). These are acidic glycoproteins of epididymal origin and are reported to bind to the sperm surface. In vitro studies have revealed that CRISP-1 prevents protein tyrosine phosphorylation and acrosome reaction reversibly, and its disassociation from the sperm surface was required for inducing capacitation (Roberts et al. 2003). However, a part of the protein remains on spermatozoa after capacitation, localized in the equatorial segment of sperm, and is involved in gamete fusion (Cohen et al. 2000; Busso et al. 2007). The observations of several studies have suggested that CRISP-1 is a multi-functional protein playing different roles during fertilization through various associations with and localization on spermatozoa (Cohen et al. 2013).
Update on pollen-food allergy syndrome
Published in Expert Review of Clinical Immunology, 2020
Pascal Poncet, Hélène Sénéchal, Denis Charpin
The diagnosis of PFAS should be considered in a patient known to suffer from a pollen allergy who consults an allergist most of the time because of ENT symptoms. The foremost deciding factor is the timing of the reaction occurring during or just following ingested food. Investigations consist first in skin prick tests performed using commercial extracts to food related to the patient’s geographic location and dietary habits. The diagnostic exactness of these tests is highly variable. When the results of the commercial testing are unexpectedly negative, the patient may be asked to plan another visit and bring fresh food to be tested. Both commercial skin prick tests and measurement of specific IgE are of reasonable sensitivity (70–100%) but moderate (40–70%) specificity using the double-blind food challenge as a reference test [17]. When available, component-resolved diagnostics is a reliable instrument in the diagnosis of PFAS, as it provides profiles based on the cross-reactive proteins. In component-resolved diagnostics, specific IgE antibodies are measured against individual allergenic molecules. This can be performed either as a single test format or in a microarray testing a range of purified allergens simultaneously. However, few allergens of classes I and II have been cloned, sequenced, and expressed as recombinant proteins. The main pan-allergens include three protein families: profilins, pathogenesis-related protein type 10 (PR-10), and nonspecific lipid transfer proteins (LTPs) (see detailed characteristics of allergens in the second chapter of this review). In Northern and Central Europe, where pollen allergy is predominantly related to birch and alder pollens, PR-10 proteins are the main cause of PFAS. Symptoms are mostly triggered by PR-10-containing Rosaceae (e.g., apple, peach). Therefore, in Northern countries PFAS represents a distinct disease with a quite unique pathogenesis [18]. In contrast, the molecules involved in PFAS in Mediterranean countries are distributed in several pollens occurring during the year. Moreover, in Mediterranean countries, patients with seasonal allergic rhinitis are frequently pollen-polysensitized. In this context, the contribution of component-resolved diagnostics to the diagnosis is probably still greater [19].