Identification of the major allergen of Malassezia globosa relevant for atopic dermatitis.

Autor: Ishibashi Y; Department of Immunobiology, Meiji Pharmaceutical University, Tokyo, Japan., Kato H, Asahi Y, Sugita T, Nishikawa A
Jazyk: angličtina
Zdroj: Journal of dermatological science [J Dermatol Sci] 2009 Sep; Vol. 55 (3), pp. 185-92. Date of Electronic Publication: 2009 Jun 18.
DOI: 10.1016/j.jdermsci.2009.05.005
Abstrakt: Background: Malasseziaglobosa constitutes a part of the normal flora of human skin, but may induce IgE production in atopic dermatitis (AD). However, information on M.globosa allergens is scant.
Objective: To identify the major M. globosa allergens by using proteomic analysis.
Methods: Immunoglobulin E (IgE) immunoblotting and cross-inhibition tests for M. globosa allergens were performed using sera from AD patients and control subjects. These allergens were identified and characterized using the proteomics approach involving a combination of two-dimensional (2D) electrophoresis, mass spectrometry, and bioinformatics tools. We cloned the cDNA of this allergen using sequences obtained by 5'- and 3'-rapid amplification of cDNA ends polymerase chain reaction.
Results: The sera of the AD patients had IgE-reactive 40-45-kDa protein components. By 2D immunoblotting, we detected a 42-kDa protein spot with an isoelectric point (pI) of 4.8; the protein was highly reactive to IgE and was designated MGp42. Full-length MGp42 cDNA contained a 1908-bp open reading frame encoding 635 amino acid residues (calculated molecular mass, 69.7kDa; pI, 6.02). The N-terminal MGp42 sequence started from the 250th residue (Asp-250) of the deduced amino acid sequence and consisted of 386 amino acid residues; these results are consistent with those of 2D immunoblotting. MGp42 showed sequence similarity to members of the heat shock protein 70 (hsp70) family. Immunoblot inhibition tests revealed no IgE cross-reactivity between MGp42 and human HSP70.
Conclusions: MGp42 may be a cleavage product of intact HSP70. This novel M. globosa allergen could be useful for the diagnosis of AD.
Databáze: MEDLINE
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