[Prokaryotic expression and immunization of glutamyl tRNA synthetase of Streptococcus suis].
OBJECTIVE
Glutamyl tRNA Synthetase (Gts) is a protease which catalyzes esterification between tRNA and glutamine. The immunogenicity of Gts was evaluated through immunization and challenge experiment.


RESULTS
We cloned gts from the genome of SC19, and inserted it into prokaryotic expression plasmid pET28a-gts. The recombinant vector was transformed into E. coli BL21. Induced by IPTG, one 58 kD protein, was expressed and purified by using Ni - NTA column (Novagen). The purity of rGtS was 93.3% and the concentration of purified protein was 433 microg/mL. We proved the immunogenicity of recombinant protein rGtS by western blot analysis. We immunized Balb/c mice with rGtS and Freund's adjuvant, and after two boost vaccinations, all mice were challenged with 4 times LD50 amount of SC19 (1.2 x 10(9) CFU). The survive rate of vaccination group is 50% (4/8), significantly higher than blank vector control group (1/8).


CONCLUSIONS
These results proved that GtS has certain immunogenicity and can offer partial protection against high dose challenge. Therefore Gts could be a potential candidate of subunit vaccine against Streptococcus suis.
Hu
Ruiming
R
State Key Laboratory of Agriculture Microbiology, Huazhong Agricultural University, Wuhan 430070, China. huruiming@gmail.com
Zhao
Zhanqin
Z
Li
Lunyong
L
Li
Zengqiang
Z
Tang
Xibiao
X
Duan
Longchuan
L
Wu
Bin
B
D000595:Amino Acid Sequence; D000818:Animals; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D015153:Blotting, Western; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005620:Freund's Adjuvant / Q000276:immunology; D005975:Glutamate-tRNA Ligase / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011897:Random Allocation; D017386:Sequence Homology, Amino Acid; D017011:Streptococcus suis / Q000201:enzymology* / Q000235:genetics
D001428:Bacterial Vaccines; D005620:Freund's Adjuvant; D005975:Glutamate-tRNA Ligase