Vacuolar serine protease is a major allergen of Cladosporium cladosporioides.
BACKGROUND
Cladosporium is an important allergenic fungus worldwide. We report here a major allergen of C. cladosporioides.


METHODS
Major C. cladosporioides allergens were characterized by immunoblotting, N-terminal amino acid sequencing, protein purification and cDNA cloning.


RESULTS
Seventy-four sera (38%) from 197 bronchial asthmatic patients demonstrated IgE binding against C. cladosporioides extracts. Among these 74 sera, 41 (55%) and 38 (51%) showed IgE binding against a 36- and a 20-kDa protein of C. cladosporioides, respectively. Both IgE-reacting components reacted with FUM20, a monoclonal antibody against fungal serine proteases. N-terminal amino acid sequencing results suggest that they are vacuolar serine proteases, and the 20-kDa component is possibly a degraded product of the 36-kDa allergen. A corresponding 5'-truncated 1,425-bp cDNA fragment was isolated. The mature protein after N-terminal processing starts with an N-terminal serine that is the ninth residue encoded by the 5'-truncated cDNA. The protein sequence deduced shares 69-72% sequence identity with Penicillium vacuolar serine proteases and was designated as Cla c 9. The purified 36-kDa Cla c 9 allergen showed proteolytic activity with peptide Z-Ala-Ala-Leu-pNA as substrate. IgE cross-reactivity was detected between the purified Cla c 9 and serine protease allergens from Aspergillusfumigatus and Penicillium chrysogenum.


CONCLUSIONS
We identified a vacuolar serine protease as a major allergen of C. cladosporioides (Cla c 9) and a major pan-allergen of prevalent airborne fungi. IgE cross-reactivity among these highly conserved serine protease pan-fungal allergens was also detectable.
Chou
Hong
H
Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan.
Tam
Ming F
MF
Lee
Lin-Hau
LH
Chiang
Chi-Huei
CH
Tai
Hsiao-Yun
HY
Panzani
Raphael C
RC
Shen
Horng-Der
HD
D000328:Adult; D000485:Allergens / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D001249:Asthma / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D001483:Base Sequence; D002963:Cladosporium / Q000201:enzymology* / Q000235:genetics / Q000276:immunology*; D003001:Cloning, Molecular; D003429:Cross Reactions; D018076:DNA, Complementary / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000276:immunology; D006801:Humans; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000276:immunology; D008969:Molecular Sequence Data; D012331:RNA, Fungal / Q000737:chemistry / Q000235:genetics; D011994:Recombinant Proteins / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification
D000485:Allergens; D018076:DNA, Complementary; D005656:Fungal Proteins; D012331:RNA, Fungal; D011994:Recombinant Proteins; D007073:Immunoglobulin E; D012697:Serine Endopeptidases