Cloning of a cDNA encoding a group-V (group-IX) allergen isoform from rye-grass pollen that demonstrates specific antigenic immunoreactivity
We have isolated and characterized the cDNA clone, 19R, that encodes an isoform of a major rye-grass pollen allergen, Lol p V [previously referred to as Lol p 1b; Singh et al., Proc. Natl. Acad. Sci. USA 88 (1991) 1384–1388; and Lol p IX; Suphioglu et al., Lancet 339 (1992) 569–572]. Clone 19R was i...
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Veröffentlicht in: | Gene 1993-12, Vol.134 (2), p.235-240 |
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Zusammenfassung: | We have isolated and characterized the cDNA clone, 19R, that encodes an isoform of a major rye-grass pollen allergen,
Lol p V [previously referred to as
Lol p 1b; Singh et al., Proc. Natl. Acad. Sci. USA 88 (1991) 1384–1388; and
Lol p IX; Suphioglu et al., Lancet 339 (1992) 569–572]. Clone 19R was isolated from a rye-grass pollen cDNA expression library using grass pollen-specific immunoglobulin E (IgE) antibodies (Ab) from an allergic serum pool. The nucleotide (nt) sequence of clone 19R potentially encodes a 33.8-kDa protein of 339 amino acids (aa). It possesses a leader peptide essentially identical to the previously characterized isoform of
Lol p V (
Lol p VA). This indicates a mature processed 31.3-kDa protein of 314aa, correlating well with the size of the polypeptides revealed by Western analysis of pollen proteins using IgE Ab affinity purified from recombinant fusion protein (reFP) encoded by clone 19R as solid matrix. There is no
N-glycosylation motif. The protein encoded by clone 19R, designated
Lol p VB, has 66.4% identity and 80.4% similarity with
Lol p VA. However, a
Lol p VA-specific monoclonal Ab, FMC A7, does not recognize reFP encoded by clone 19R, indicating that
Lol p VB does not share this epitope. Cross-reactivity studies using affinity purified IgE Ab showed that both isoforms share similar allergenic epitopes. Immunoblot analysis using sera from a population of 30 patients showed that 80% possess IgE Ab that recognize both
Lol p V isoforms. Variation occurred in the signal intensities of IgE binding. Like
Lol p VA,
Lol p VB is pollen specific and is part of the same multigene family. |
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ISSN: | 0378-1119 1879-0038 |
DOI: | 10.1016/0378-1119(93)90099-O |