<i>Fusarium solani</i>: Immunochemical Characterization of Allergens

Abstract

Allergenic components of the fungus Fusarium solani were isolated using (NH₄)₂SO₄ precipitation and ion-exchange column chromatography. The allergenicity of fractions was studied by enzyme-linked immunosorbent assay and radioallergosorbent test inhibition techniques. Proteins of culture filtrate (CF), mycelium (MY), and spore (SP) extracts of F. solani were characterized by isoelectrofocusing, sodium dodecyl sulphate-polyacrylamide gel electrophoresis, and IgE-specific immunoblotting. CF antigen of F. solani contained more allergenic proteins than MY and SP, visible on immunoblot analysis using allergenic serum pool. A 65-kD protein component of CF was found to be a major allergen, as it was strongly visible on immunoblots of all 15 patient sera tested. Crossed immunoelectrophoresis and enzyme-linked immunosorbent assay inhibition using rabbit antibodies raised against F solani CF demonstrated shared antigenicity between CF, MY, and SP extracts. It was observed that F. solani is a significant allergen, and most of the allergens of MY and SP extracts were found in CF extract. Therefore, CF alone can be used in the preparation of a standard extract. However, few unique allergenic proteins were observed in MY as well as in SP extracts of F. solani. Hence, the use of combined CF, MY, and SP extracts of F. solani is recommended for diagnosis and immunotherapy.

Immunobiology of Fungal Allergens

“…In addition to these fungi, Saccharomyces, M. furfur, C. albicans and Trichophyton species that invade the skin have been implicated in allergic diseases [6, 9, 59, 60, 61, 62, 63]. Several mushrooms and other Basidiomycetes spores have also been implicated in fungal allergy [59].…”

Culture filtrate antigens and allergens of Epicoccum nigrum cultivated in modified semi-synthetic medium

“…The use of peptone and other natural ingredients for preparing CF antigens have been refuted, and the use of synthetic media is suggested [11]. The CF components of A. fumigatus, Fusarium species, C. albicans, and Penicillium notatum are more potent and are easily obtained by cultivating them in the synthetic medium [23,13,7]. The growth of EN in synthetic medium was poor [1].…”

“…Spores, mycelia and culture filtrate (CF) allergens of Alternaria alternata, Aspergillus fumigatus, Candida albicans, Cladosporium herbarum, and Fusarium solani, etc. have been documented as important sources of fungal allergens [21,23,24,13]. The CF extracts from these fungi have been standardized and used for purifying and characterizing one or more major allergens.…”

“…However, the metabolic or CF allergens of this fungus have not been described. In general, the culture fluid obtained with other fungi contains a greater variety of antigens than do cellular extracts and hence is used successfully for allergy diagnosis [23,24,13]. CF allergens are obtained by growing the fungi in complete synthetic medium.…”

Spectrum of Allergens and Allergen Biology in India

“…Most of the allergy-eliciting indoor moulds reported from different Indian megacities were filamentous and present in the air around the year. Extracts of the Fusarium solani culture filtrate, mycelium, and spores were analysed by immunoblotting with sera from asthmatics that led to the identification of 23 new allergens [79]. A 45-kDa cross-reactive protein displayed IgE reactivity with all of the test sera (i.e., 100% frequency) and thus is considered as a major allergen [80].…”