Basidiomycete Allergy: Identification and Characterization of an Important Allergen from <i>Calvatia cyathiformis</i>

Abstract

Basidiomycetes were not considered as major aeroallergen sources until spore traps revealed the prevalence of basidiospores, which were in some cases associated with epidemic outbreaks of asthma. More recently, we established that approximately one third of subjects with respiratory allergic disease were skin prick test positive to basidiospore extracts. Bronchial challenge with these extracts induced reversible immediate and late phase bronchospasm in sensitive subjects. Screening individual RAST-positive sera for reactivity to immunoprinted Calvatia cyathiformis spore extract indicated that a basic component with pI 9.3 reacted with 63% of test sera. Further analysis by RAST and immunoprint (IP) inhibition showed that this component, Calc Bd9.3, appeared to cross-react with spore extracts from 3 of 5 other species tested. To isolate this component for additional analysis, a protocol was used with two sequential stages of preparative isoelectric focusing (IEF) followed by hydrophobic interaction chromatography. This yielded purified Cal c Bd9.3 that retained IgE-binding activity by IP, was a single band by IEF and SDS-PAGE (16 kD) analysis when stained with Coomassie blue. Double diffusion in gel with rabbit antiserum to Cal c BD9.3 demonstrated a single precipitin band in crude extract that was identical to that obtained with purified Cal c Bd9.3. By IP this antiserum recognized pure Cal c Bd9.3 and the 9.3 band in crude extracts from C. cyathiformis and 3 other species, corroborating the cross-reactivity. However, other bands were also recognized. These studies indicate that basidiospores are major fungal aeroallergens, many of which contain a common basic allergen to which most sensitized subjects react.

Identification of <i>Psilocybe cubensi</i><i>s</i> Spore Allergens by Immunoprinting

“…Unpublished studies indicate that the pi 9.3 band in P. cubensis has a molecular weight of less than 20 kD. This is similar to the Cal c Bd9.3, the pi 9.3 al lergen from P cyathiformis spores which has a molecular weight of 16 kD [25]. The 9.3 allergen cross-reacts by im munoprint inhibition among C. cyathiformis, Pleurotus ostreatus, Coprinus quadrifdus and P. cubensis [20].…”

“…By each electrophoresis method, one allergen, at 35 kD and pi 9.3, reacted with all sera tested. Such highly reactive allergens have not been reported from other Basidiomycetes investigated [24][25][26][27][28][29][30], The most reac tive basidiomycete allergen yet described, designated as Cal c Bd9.3 from Calvaba cyathiformis, reacted with only 68% of test sera. The number of allergens recognized var ied among sera.…”

Sensitization to Airborne Ascospores, Basidiospores, and Fungal Fragments in Allergic Rhinitis and Asthmatic Subjects in San Juan, Puerto Rico

“…These antibodies allowed the detection and quantification of sensitization to specific and characterized allergens; however, this is not possible with many airborne allergens, including fungal spores and fragments, as there are only monoclonal antibodies to few fungi. In the case of basidiomycetes, allergens have been fully described in just a few cases [32,33] and, to our knowledge, there are no published studies of monoclonal antibodies to basidiomycete allergens. …”

“…), 1 ascomycete ( Chaetomium spp. ), animals (dog, cat, mite, and cockroach), pollen (Bermuda, Johnson, Bahia, and trees), and crude extracts from basidiomycetes’ spore prints (Ganoderma applanatum, Chlorophyllum molybdites, and Pleurotus ostreatus) which were prepared as previously described by Horner et al [32]. …”

“…This is not the case in temperate regions, in which mitospores (deuteromycetes or Fungi Imperfecti) such as Cladosporium and Alternaria are the most common. Numerous studies have described the allergenic potential of these spores in temperate areas [16,29,30,31], but very few have demonstrated the same potential with basidiospores and ascospores, or directly with airborne fungal spores, due to the difficulty of preparing extracts [24,25,26,32,33]. …”