This truncated TSOL16A cDNA (herein referred to as TSOL16 with respect to the cDNA and encoded protein) was cloned directionally into the EcoRI and XhoI sites of pGEX-1TEX and transformed into E. coli JM109 strain by electroporation. Use of the pGEX plasmid allowed
expression and purification of TSOL16 as a fusion with glutathione S-transferase (GST) . The truncated TSOL16 cDNA was excised from pGEX-1 by digestion with EcoRI and XhoI, HKI-272 order and cloned into EcoRI/SalI-digested pMAL-C2. The pMAL-C2 plasmid allowed expression and purification of TSOL16 as a fusion with maltose binding protein (MBP) . The plasmid construct was transformed into E. coli JM109. The TSOL45-1A protein was cloned into the pGEX and pMAL-C2 plasmids, and expressed in E. coli as a fusion protein with GST and MBP as described in . The TSOL45-1A fusion proteins lacked 16 N-terminal amino acids that encoded a predicted secretory signal. The TSOL45-1B
cDNA was originally cloned from T. solium oncosphere mRNA as described in . TSOL45-1B lacked exon II of the TSOL45-1 gene. PCR amplification was used to produce a cDNA construct that encoded a protein also lacking the 16 N-terminal amino acids of the secretory signal. The following PCR primers were used to amplify TSOL45-1B for cloning into pGEX and pMAL as described above: 5′CCG GAA TTC GGA AAC CAC AAG GCA ACA TC3′; 5′CCG CTC GAG GGA AAT GGG CAT TGA CCG3′. E. coli SAR405838 molecular weight cultures expressing TSOL16, TSOL45-1A and TSOL45-1B were prepared and recombinant fusion proteins were purified as detailed in . Freeze-dried aliquots of antigens were prepared by the addition of Quil A adjuvant (1 mg per dose) and a much sixfold (w/w) amount of maltose as a stabilizing agent for transport to Lima, Peru, where
the vaccine trial was conducted. Aliquots of GST and MBP, for use as negative controls, were also prepared for the vaccine trial. The antigens were reconstituted in sterile de-ionized water immediately prior to vaccination of pigs. The purified GST and MBP fusions of TSOL16, TSOL45-1A and TSOL45-1B were tested in a pig vaccine trial against challenge infection with T. solium. The study was reviewed and approved by the Animal Ethics Committee of the School of Veterinary Medicine, Universidad de San Marcos, Lima, Peru. Twenty 8-week old piglets were obtained from a cysticercosis free farm located in Huaral, Lima. Animals were divided into four groups of 5 pigs each. All animals were vaccinated against Classical Swine Fever prior to the start of the trial. Each pig received 200 μg of antigen and 1 mg Quil A (Brenntag Biosector, Denmark) per immunization in a 1 ml dose. Immunizations were given intramuscularly in the right hind-quarter via a 0.9 mm × 38 mm needle and 1 ml syringe (Becton Dickinson, U.K.). Piglets received their first immunization with recombinant antigen prepared as a GST fusion.