Screening specific allergens of allergic asthma from DNA expression library of Humulus pollen

Objective To screen the allergic asthma-specific allergen from complementary DNA (cDNA)expression library of humulus pollen.Methods Screened the humulus pollen λTripIEx2 cDNA expression library which had been constructed using the method of immunological screening with patients' blood serum of humulus pollen allergic asthma,extracted the positive phage DNA and the positive phage DNA.and identitied by double restriction enzyme with EcoR Ⅰ,Hind Ⅲ and agarose gel electrophoresis.Then the DNA fragments were sequenced and the repeats and sequence homology were analyzed.Results After 3 rounds of screening,three specific allergic cDNA clone of humulus pollen were obtained and the sequences were 868,550 and 592 base pairs respectively.The results of sequencing showed that these three clones represented different cDNA sequences.The repeats analysis found no repeats and these clones had no high homology with any known gene.Conclusions Three specific allergic cDNA clones of humulus pollen obtained may be new genes.It provides a rational basis for constructing a recombinant allergen or nuclear acid vaccine. Key words: Humulus; Pollen; Asthma; Allergens; DNA; complementary; Sequence analysis