[Cloning and expression of subunit genes of pertussis toxin and its immunological evaluation].
OBJECTIVE
To clone the gene encoding pertussis toxin (PT) from Bordetella Pertussis CS strain and five genes encoding subunits of PT, to investigate the possibility of expressing the genes encoding for mature methionyl subunits of PT in insect cell and to evaluate the immunological characteristics of recombinant subunits.


METHODS
The genes encoding for PT and its subunits were cloned by PCR and confirmed by restriction enzyme digestion and Southern blot. Using recombinant baculovirus technology, the recombinant subunits were expressed in Sf9 insect cells and analyzed by immunofluorescence assay. The immunological properties of recombinant subunits were analyzed by ELISA.


RESULTS
The genes encoding for PT and its subunits were cloned and expressed in Sf9 cells. The level of specific antibodies against nature PT induced by five recombinant subunits polymerized was higher than that unpolymerized and polymerized by four recombinant subunits (without S1) in mice. The results indicate that PT subunits had weak ability to induce specific antibodies against PT, and also anti-nature PT sera had poor recognition to PT subunits.


CONCLUSIONS
The ability of PT to induce specific antibody is conformation dependent of intact PT, and antibody induction domains are located dominantly in S1 subunit of intact PT.
National Vaccine Serum Institute, Beijing.
F
F
Han
D
D
Liu
Z
Z
Xiao
D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D001886:Bordetella pertussis / Q000235:genetics; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D051379:Mice; D037342:Pertussis Toxin; D011994:Recombinant Proteins; D010566:Virulence Factors, Bordetella / Q000235:genetics* / Q000276:immunology
D011994:Recombinant Proteins; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin