Agar

Example 6

TbpB and NMB0313 genes were amplified from the genome of Neisseria meningitidis serotype B strain B16B6. The LbpB gene was amplified from Neisseria meningitidis serotype B strain MC58. Full length TbpB was inserted into Multiple Cloning Site 2 of pETDuet using restriction free cloning ((F van den Ent, J. Löwe, Journal of Biochemical and Biophysical Methods (Jan. 1, 2006)).). NMB0313 was inserted into pET26, where the native signal peptide was replaced by that of pelB. Mutations and truncations were performed on these vectors using site directed mutagenesis and restriction free cloning, respectively. Pairs of vectors were transformed into E. coli C43 and were grown overnight in LB agar plates supplemented with kanamycin (50 μg/mL) and ampicillin (100 μg/mL).

tbpB genes were amplified from the genomes of M. catarrhalis strain 035E and H. influenzae strain 86-028NP and cloned into the pET52b plasmid by restriction free cloning as above. The corresponding SLAMs (M. catarrhalis SLAM 1, H. influenzae SLAM1) were inserted into pET26b also using restriction free cloning. A 6His-tag was inserted between the pelB and the mature SLAM sequences as above. Vectors were transformed into E. coli C43 as above.

Cells were harvested by centrifugation at 4000 g and were twice washed with 1 mL PBS to remove any remaining growth media. Cells were then incubated with either 0.05-0.1 mg/mL biotinylated human transferrin (Sigma-aldrich T3915-5 MG), α-TbpB (1:200 dilution from rabbit serum for M. catarrhalis and H. influenzae; 1:10000 dilution from rabbit serum for N. meningitidis), or α-LbpB (1:10000 dilution from rabbit serum-obtained a gift from J. Lemieux) or α-fHbp (1:5000 dilution from mouse, a gift from D. Granoff) for 1.5 hours at 4° C., followed by two washes with 1 mL of PBS. The cells were then incubated with R-Phycoerythrin-conjugated Streptavidin (0.5 mg/ml Cedarlane) or R-phycoerythrin conjugated Anti-rabbit IgG (Stock 0.5 mg/ml Rockland) at 25 ug/mL for 1.5 hours at 4° C. The cells were then washed with 1 mL PBS and resuspended in 200 uL fixing solution (PBS+2% formaldehyde) and left for 20 minutes. Finally, cells were washed with 2×1 mL PBS and transferred to 5 mL polystyrene FACS tubes. The PE fluorescence of each sample was measured for PE fluorescence using a Becton Dickinson FACSCalibur. The results were analyzed using FLOWJO software and were presented as mean fluorescence intensity (MFI) for each sample. For N. meningtidis experiments, all samples were compared to wildtype strains by normalizing wildtype fluorescent signals to 100%. Errors bars represent the standard error of the mean (SEM) across three experiments. Results were plotted statistically analysed using GraphPad Prism 5 software. The results shown in FIG. 6 for the SLPs, TbpB (FIG. 6A), LbpB. (FIG. 6B) and fHbp (FIG. 6C) demonstrate that SLAM effects translocation of all three SLP polypeptides in E. coli. The results shown in FIG. 10 demonstrate that translocation of TbpB from M. catarrhalis (FIG. 10C) and in H. influenzae (FIG. 10D) in E. coli require the co-expression of the required SLAM protein (Slam is an outer membrane protein that is required for the surface display of lipidated virulence factors in Neisseria. Hooda Y, Lai C C, Judd A, Buckwalter C M, Shin H E, Gray-Owen S D, Moraes T F. Nat Microbiol. 2016 Feb. 29; 1:16009).

Example 8

In selecting genomes for a given bacterial species where a SLAM homolog was identified, preference was given to reference genomes that contained fully sequenced genomes. SLAM homologs were identified using iterative Blast searches into closely related species to Neisseria to more distantly related species. For each of the SLAM homologs identified in these species, the corresponding genomic record (NCBI genome) was used to identify genes upstream and downstream along with their corresponding functional annotations (NCBI protein database, Ensembl bacteria). In a few cases, no genes were predicted upstream or downstream of the SLAM gene as they were too close to the beginning or end of the contig, respectively, and thus these sequences were ignored.

Neighbouring genes were analyzed for 1) an N-terminal lipobox motif (predicted using LipoP, SignalP), and 2) a solute binding protein, Tbp-like (InterPro signature: IPR or IPR011250), or pagP-beta barrel (InterPro signature: IPR011250) fold. If they contained these elements, we identified the adjacent genes as potential SLAM-dependent surface lipoproteins.

A putative SLAM (PM1515, SEQ ID NO: 1087) was identified in Pasteurella multocida using the Neisseria SLAM as a search. The putative SLAM (PM1515, SEQ ID NO: 1087) was adjacent to a newly predicted lipoprotein gene with unknown function (PM1514, SEQ ID NO: 1083) (FIG. 11A). The putative SLAM displayed 32% identity to N. meningitidis SLAM1 while the SLP showed no sequence similarity to known SLAM-dependent neisserial SLPs.

The putative SLAM (PM1515, SEQ ID NO: 1087) and its adjacent lipoprotein (PM1514, SEQ ID NO: 1083) were cloned into pET26b and pET52b, respectively, as previously described and transformed into E. coli C43 and grown overnight on LB agar supplemented with kanamycin (50 ug/ml) and ampicillin (100 ug/ml).

Cells were grown in auto-induction media for 18 hours at 37 C and then harvested, washed twice in PBS containing 1 mM MgCl2, and labeled with α-Flag (1:200, Sigma) for 1 hr at 4 C. The cells were then washed twice with PBS containing 1 mM MgCl2 and then labeled with R-PE conjugated α-mouse IgG (25 ug/mL, Thermo Fisher Scientific) for 1 hr at 4 C. following straining, cells were fixed in 2% formaldehyde for 20 minutes and further washed with PBS containing 1 mM MgCl2. Flow Cytometry was performed with a Becton Dickinson FACSCalibur and the results were analyzed using FLOWJO software. Mean fluorescence intensity (MFI) was calculated using at least three replicates was used to compare surface exposure the lipoprotein in strains either containing or lacking the putative SLAM (PM1515) and are shown in FIG. 11C and FIG. 11D. PM1514 could be detected on the surface of E. coli illustrating i) that SLAM can be used to identify SLPs and ii) that SLAM is required to translocate these SLPs to the surface of the cell—thus identifying a class of proteins call “SLAM-dependent surface lipoproteins”. Antibodies were raised against purified PmSLP (PM1514) and the protein was shown to be on the surface of Pasteurella multocida via PK shaving assays.

Example 12

Plant transformation—The Arabidopsis thaliana var Columbia (To plants) were transformed according to the Floral Dip procedure [Clough S J, Bent A F. (1998) Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana. Plant J. 16(6): 735-43; and Desfeux C, Clough S J, Bent A F. (2000) Female reproductive tissues were the primary targets of Agrobacterium-mediated transformation by the Arabidopsis floral-dip method. Plant Physiol. 123(3): 895-904] with minor modifications. Briefly, Arabidopsis thaliana Columbia (C010) T₀ plants were sown in 250 ml pots filled with wet peat-based growth mix. The pots were covered with aluminum foil and a plastic dome, kept at 4° C. for 3-4 days, then uncovered and incubated in a growth chamber at 18-24° C. under 16/8 hours light/dark cycles. The T₀ plants were ready for transformation six days before anthesis.

Single colonies of Agrobacterium carrying the binary vectors harboring the genes of some embodiments of the invention were cultured in YEBS medium (Yeast extract 1 gr/L, Beef extract 5 gr/L, MgSO₄*7H₂O, Bacto peptone 5 gr/L) supplemented with kanamycin (50 mg/L) and gentamycin (50 mg/L). The cultures were incubated at 28° C. for 48 hours under vigorous shaking to desired optical density at 600 nm of 0.85 to 1.1. Before transformation into plants, 60 μl of Silwet L-77 was added into 300 ml of the Agrobacterium suspension.

Transformation of T₀ plants was performed by inverting each plant into an Agrobacterium suspension such that the above ground plant tissue was submerged for 1 minute. Each inoculated T₀ plant was immediately placed in a plastic tray, then covered with clear plastic dome to maintain humidity and was kept in the dark at room temperature for 18 hours to facilitate infection and transformation. Transformed (transgenic) plants were then uncovered and transferred to a greenhouse for recovery and maturation. The transgenic T₀ plants were grown in the greenhouse for 3-5 weeks until siliques were brown and dry, then seeds were harvested from plants and kept at room temperature until sowing.

For generating T₁ and T₂ transgenic plants harboring the genes of some embodiments of the invention, seeds collected from transgenic T₀ plants were surface-sterilized by exposing to chlorine fumes (6% sodium hypochlorite with 1.3% HCl) for 100 minutes. The surface-sterilized seeds were sown on culture plates containing half-strength Murashig-Skoog (Duchefa); 2% sucrose; 0.5% plant agar; 50 mg/L kanamycin; and 200 mg/L carbenicylin (Duchefa). The culture plates were incubated at 4° C. for 48 hours and then were transferred to a growth room at 25° C. for three weeks. Following incubation, the T₁ plants were removed from culture plates and planted in growth mix contained in 250 ml pots. The transgenic plants were allowed to grow in a greenhouse to maturity. Seeds harvested from T₁ plants were cultured and grown to maturity as T2 plants under the same conditions as used for culturing and growing the T₁ plants.