OBJECTIVETo develop a novel dual-modified vaccine, the superantigen-linked intestine-carcinoma cells expressing membrane-bound heat shock protein 70 (HSP70), and further examine its anticancer therapeutic effect.

METHODSThe pre-established intestine carcinoma CT26 line expressing membrane-bound heat shock protein 70 (HSP70) was amplified and incubated with superantigen fusion protein, staphylococcal enterotoxin A (SEA) fused with transmembrane sequence (SEA-TM), thereby the dual-modified vaccine was prepared after inactivation. The anticancer efficacy of the vaccine was examined.

RESULTSThe laser confocal microscopy and flow cytometry showed that there co-existed much HSP70 and SEA on the vaccine membrane surface. Both of the single-modified vaccines, the SEA-linked vaccine and membrane-bound-HSP70-expressing one, displayed marked tumor suppression, a prolonged survival period, augmented lymphocyte proliferation and higher NK and CTL activity in the vaccinated mice when compared with its counterpart. Furthermore, the dually modified vaccine induced lymphocyte proliferation most intensively, generated the highest NK and CTL activity as well as the strongest tumor rejection in the vaccinated mice. The survival period of the mice was further prolonged.

CONCLUSIONA new vaccine, SEA-linked and membrane-bound-HSP70-expressing intestine-carcinoma cells can induce more potent anticancer immunity and produce better therapeutic efficacy.