1 volumes of 25% fresh yeast extract. Mycoplasmas were grown at 37°C in 5% CO2 until stationary growth phase and harvested by centrifugation at 20000 g for 20 min. For genetic manipulation and subcloning, E. coli strains TG1 (Stratagene, La Jolla, CA, USA), DH5α, Top10 (Invitrogen, Carlsbad, CA, USA) and BL21 Star™ (DE3) (Invitrogen) were used. The phage display vector fdtet 8.53 was a gift from Dr. V. K. Chaudhary, University of Delhi, New Delhi, India. Antisera, antibodies, and immunoblot analysis
Anti-ORF5 immune serum was obtained by injecting rabbits with amino acid residues 328-478 of the 486 aa proline-rich MmmSC ORF5 [22]. Bovine sera and bronchoalveolar lavage (BAL) from animals C11 (recovered from a sub-acute to chronic experimental infection) and T1 (uninfected control) were from 10058-F4 molecular weight Dr. M. Niang, Central Veterinary Laboratory, Bamako, Mali [4, 19]. The seven bovine sera used in screening and immunoblotting were a kind gift from the Botswana National Veterinary Laboratory in Gabarone, buy PF-01367338 Botswana [18].
Antibodies were isolated using ImmunoPure® Protein G columns (Pierce, Rockford, IL, USA). Antibody-containing fractions were applied to Excellulose™ GF-5 Desalting columns (Pierce). Before selection by panning, unwanted filamentous phage antibodies were removed from the C11 serum by cross-absorption [41]. BAL IgA from animal C11 and serum IgA from Botswana cattle were used in pannings, but a limited volume was available and the samples were not cross-absorbed. Negative control pannings using BAL IgA and total IgG from the control animal (T1) were also performed. Immunoblotting was performed according to IKBKE standard protocols. A volume of 10 μl of each of the seven sera from Botswana were added to 5 ml of 1% milk powder (MP) suspended in PBS, pH 7.4. Blots were incubated overnight in the pool of diluted sera at room temperature. For the detection of bound antibodies, sheep horseradish peroxidise conjugated anti-bovine IgG (catalogue No. PP200; The Binding Site, Birmingham, UK) was diluted 1:10000 and incubated with the blot for an hour at room temperature. Bound antibodies were detected after incubation of the blot with SuperSignal® West Pico PCI-32765 ic50 chemiluminescent substrate
(Pierce) using the Lumi-Imager from Roche Molecular Biochemicals. Display library construction Phage library construction using the pIII phage display vector fdtet 8.53 was as described by Gupta and co-workers [42]. This entailed ligating blunt-ended fragments of MmmSC genomic DNA in the presence of the restriction enzyme SrfI and T4 DNA ligase. The extent to which the genome was represented in the primary library with a theoretical probability of 0.99 was calculated using the method of Clarke and Carbon [43]. To deplete the resulting phage repertoire of any peptides that may have been susceptible to binding by irrelevant antibodies present in healthy bovine serum, a 50 μl volume was incubated with 2 mg of naïve bovine IgG at 4°C overnight.