Five pigs free of A. pleuropneumoniae were inoculated intratracheally at dose of 1.0 × 107CFU/pig

in PBS to prepare the convalescent sera, and three pigs survived. Twenty days after the first infection, the survivors were rechallenged with another identical dose of JL03. Sera were collected a week after the second inoculation and evaluated. Antibody titer of mixed sera from survivors 1:512 was selleck chemical measured by IHA kit (Lanzhou Bioproducts Factory, Lanzhou, China). Sera were collected before inoculation as control sera. All animals were housed and maintained in isolation facilities in accordance with the Animal Care and Use Committee guidelines of Huazhong Agricultural University. 2-DE and immunoblotting analysis IEF was performed with the IPGphor II™ system (GE Healthcare, USA) and the Immobiline DryStrip™ IPGstrips of 13 cm

(linear 3–10 pH gradient) according to Gorg et al[54]. The prepared ECPs and OMPs (150 μg/strip) was mixed with rehydration buffer (7 M urea, 2 M thiourea, 2% w/v CHAPS, 1%w/v DTT, 0.5%v/v IPG buffer, 0.002% w/v bromophenol blue). The ECPs and OMPs samples were focused for 50 kVh and 75 kVh respectively. After IEF, three gels were run as follows. The IPGstrips were respectively equilibrated for 15 min with 10 mg/ml DTT and 40 mg/ml iodoacetamide in equilibration selleck chemicals llc buffer (6 M urea, 2% w/v SDS, 30% v/v glycerol, 0.002% w/v bromophenol blue, 50 mM Tris-HCl, pH 8.8). After equilibration, the second dimension electrophoresis was performed on a 10% SDS polyacrylamide gel using Hoefer SE600 Ruby (Amersham Biosciences). Proteins of one gel were visualized by staining with silver nitrate (Bio Basic Inc). And gel evaluation and data analysis were carried out

using the ImageMaster v 6.01 program (GE Healthcare, USA). Immunoblot was performed according to Mansfield [55]. Gels were blotted onto PVDF transfer membranes (Hybond-P, 0.45 mm; Amersham Biosciences). The membranes were blocked in 5% BSA in TBS +0.05%(v/v) Tween 20 for 1 h at room temperature and probed with the convalescent swine sera and control sera (1:1000), for 1 h at room temperature, and then were washed and incubated with goat anti-porcine IgG (H+L) -HRP (1:5,000) MycoClean Mycoplasma Removal Kit (Southern Biotech, Birmingham, AL, USA) for 1 h at room temperature, followed by development with Supersignal west pico chemiluminescent substrate (Pierce, Rockford, IL, USA) and imaged on the Image Station 2000 MM (Kodak, Rochester, NY, USA). All experiments were done in triplicate. In-gel digestion of proteins[5] Protein spots of interest were excised from gels and detained with 100 μl 30 mM potassium ferricyanide and 100 μl 100 mM sodium thiosulfate (at a ratio of 1:1). And the gel pieces were selleck compound shrunken with 50 μl acetonitrile and then re-swollen with 5 μl of 25 mM ammonium bicarbonate containing 10 ng of trypsin at 4°C for 30 min. In-gel tryptic degradation was performed overnight at 37°C, followed by three subsequent extractions.