5°C, 1 min; 72°C, 1 min and a 72°C 10 min final extension. The VP4 gene PCR product was cleaved with BamHI and XhoI and ligated into the corresponding sites of pPG612.1 digested with BamHI and XhoI, respectively, giving rise to pPG612.1-VP4. A gene fragment of about 375 bp encoding the E. coli LTB

structural polypeptide was amplified by PCR using the forward primer 5′-AAGGTCGACTGCTGTVVGATGAATAAAGTAAAATGTTAT-3′ (SalI site underlined) and the reverse primer 5′-AAGCTCGAGCTAGTTTTCCATACTGATTGCCG-3′(XhoI site underlined). PCR amplification conditions were as follows: 95°C, 5 min followed by 30 cycles of 1 min at 94°C; 1 min, 56°C; 1 min, 72°C and a final extension at 72°C for 10 min. The LTB PCR product was cleaved with SalI and XhoI and inserted into the corresponding sites in pPG612.1-VP4 digested with SalI and XhoI, giving rise to pPG612.1-VP4-LTB (Figure 8). Figure 8 click here Target amplification fragments of VP4 and VP4-LTB fusion Avapritinib cost gene. Lane 1,5: Blank controls; Lanes 2: Target amplification fragment of VP4 gene; Lanes 3: 2000 bp DNA marker; Lane 4:Target amplification fragment of VP4-LTB fusion

gene. Electroporation of L. casei was carried out as previously described [44]. Briefly, plasmid DNA (10 μl) was added to 150 μl of L. casei 393, gently mixed at 4°C for 5 min and subjected to a single electric pulse (25 μF of 2.5 kV/cm). The mix was then incubated in MRS medium without Cm at 37°C anaerobically for 2 h. Recombinant strains were selected on MRS-agar medium containing 10 μg/ml of Cm. The sequences of the respective L. casei 393 transformants were confirmed by plasmid DNA sequencing. Protein expression and Western-blot analysis To analyze buy AZD5582 the expression of the VP4 and VP4-LTB fusion protein following xylose induction of rLc393:pPG612.1-VP4 and pPG612.1-VP4-LTB, respectively, overnight cultures grown in basal MRS broth Glycogen branching enzyme supplemented with xylose (or glucose as a negative induction control)

and pellets collected by centrifugation at 12,000 × g for 10 min. The pellets were washed twice with sterile 50 mM Tris-Cl, pH 8.0 and treated with 10 mg/ml lysozyme at 37°C for 60 min. The lysates were centrifuged at 12000 × g for 10 min and subjected to 10% sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and either stained with Coomassie blue or electrotransferred onto nitrocellulose membranes. The immunoblots were blocked with PBS containing 5% skimmed milk for 2 hr at 37°C. Blots were washed three times between all steps for ten minutes. Blots were incubated with 1:800 dilution(100 μL) of mouse anti-VP4 antibodies in phosphate-buffered saline (PBS), washed and then probed with a horseradish peroxidase (HRP)-conjugated goat anti-mouse IgG (Sigma) diluted at 1:2500(100 μL) in PBS. The blots were washed and incubated with the Chemiluminescent Substrate reagent (Pierce, Rockford, IL) according to the manufacturer’s instruction. Control blots incubated with secondary antibody only did not result in visible protein band reactivity.