Cloning and expression of Taenia ovis antigens in Escherichia coli

摘要: Double stranded DNA complementary to poly(A)+ mRNA from the tapeworm Taenia ovis was cut with Sau 3A an average length of about 300 bp and inserted into Bam HI site expression plasmids pEX1, pEX2 pEX3. These express a hybrid protein derived fusion cro gene lac Z (truncated at its 5' end by 53 bp) phage lambda. Cloning sites lie downstream fusion. Escherichia coli infected another plasmid (pCI857) bearing temperature sensitive repressor lambda transformed pEX which T. had been inserted; recombinants were selected growth 30 degrees C in presence ampicillin 100 micrograms ml-1. Replicas made induced transferring them 42 C. Several expressing antigenic determinants detected sheep serum that absorbed remove antibodies E. coli. Of five for further study, three expressed proteins between 165 170 kDa component contributed 48 55 kDa; other two, contribution 0.5 1.5 kDa. may be some interest respect vaccine development since they are during normal course infection sheep, also present oncosphere - infective larva parasite stimulates immunity sheep. The native antigens adult worms oncospheres correspond produced recombinant clones comprise number species ranging 92.5 180 Tests affinity purified indicate products represent different epitopes on same subset polypeptides both oncospheres.