Published online Apr 15, 2002. doi: 10.3748/wjg.v8.i2.294
Revised: June 3, 2001
Accepted: July 10, 2001
Published online: April 15, 2002
AIM: To characterize the biochemical and immunological properties of an experimental ISCOMS vaccine prepared from a novel therapeutic polypeptide based on T cell epitopes of HBsAg, and a heptatis B-ISCOMS was prepared and investigated.
METHODS: An immunostimulating complexes (ISCOMS)-based vaccine containing a novel therapeutic hepatits B polypeptide was prepared by dialysis method, and its formation was visualized by electron microscopy and biochemically verified by SDS-polyacrylamide gel electrophoresis. Amount of the peptide within ISCOMS was determined by Bradford assay, and specific CTL response was detected by ELISPOT assay.
RESULTS: Typical cage-like structures of submicroparticle with a diameter of about 40 nm were observed by electron microscopy. Results from Bradford assay showed that the level of peptide incorporation was about 0.33 g•L⁻¹. At the paralleled position close to the sixth band of the molecular weight marker (3480 kDa) a clear band was shown in SDS-PAGE analysis, indicating successful incorporation of polypeptide into ISCOMS. It is suggested that ISCOMS delivery system could efficiently improve the immunogenicity of polypeptide and elicit specific immune responses in vivo by the results of ELISPOT assay, which showed that IFN-γ producing cells (specific CTL responses) were increased (spots of ISCOMS-treated group: 47 ± 5, n = 3; control group: 5 ± 2, n = 3).
CONCLUSION: ISCOMS-based hepatitis B polypeptide vaccine is successfully constructed and it induces a higher CTL response compared with short polypeptides vaccine in vivo.