Isolation and immunological characterization of a novel Cladosporium herbarum allergen structurally homologous to the alpha/beta hydrolase fold superfamily.
Because the ascomycete Cladosporium herbarum embodies one of the most important, world-wide occurring fungal species responsible for eliciting typical IgE-mediated hypersensitivity reactions ranging from rhinitis and ocular symptoms to severe involvement of the lower respiratory tract, a more comprehensive definition of its detailed allergen repertoire is unquestionably of critical medical as well as therapeutic significance. By screening a C. herbarum cDNA library with IgE antibodies pooled from 3 mold-reactive sera, we were able to identify, clone and affinity-purify a novel allergen candidate (29.9 kDa) exhibiting considerable (three-dimensional) homology to the alpha/beta hydrolase fold superfamily. The latter covers a collection of hydrolytic enzymes of widely differing phylogenetic origin as well as catalytic activity (operating in countless biological contexts) that in general exhibit only little sequence similarity yet show a remarkable conservation of structural topology. Our present study (i) characterizes recombinant non-fusion C. herbarum hydrolase as a natively folded, minor mold allergen that displays a prevalence of IgE reactivity of approximately 17% in our in vitro immunoblot experiments, (ii) proposes the existence of several putative (speculatively cross-reactive) ascomycete orthologues as determined via genome-wide in silico predictions, and (iii) finally implies that C. herbarum hydrolase could be included in forthcoming minimal testing sets when fungal allergy is suspected.
Rid
Raphaela
R
Department of Cell Biology, Division of Genetics, University of Salzburg, Salzburg, Austria. Raphaela.Rid@sbg.ac.at
Onder
Kamil
K
Hawranek
Thomas
T
Laimer
Martin
M
Bauer
Johann W
JW
Holler
Claudia
C
Simon-Nobbe
Birgit
B
Breitenbach
Michael
M
D000485:Allergens / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002963:Cladosporium / Q000201:enzymology* / Q000276:immunology*; D006801:Humans; D006867:Hydrolases / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification*; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000276:immunology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D020673:Protein Renaturation; D011994:Recombinant Proteins / Q000276:immunology; D016415:Sequence Alignment; D040681:Structural Homology, Protein
D000485:Allergens; D011994:Recombinant Proteins; D007073:Immunoglobulin E; D006867:Hydrolases