BACKGROUNDTo study the cell immunity induced by lung cancer B7 vaccine, FLB2C cells.

METHODSCompared withparental lung cancer cell LA795 line, proliferation of mouse T lymphocytes stimulated by FLB2C was observed through mixed lymphocyte culture. CTLL cell MTT test was used to detect whether FLB2C stimulated T lymphocyte to secrete IL-2. After immunized with the FLB2C and LA795 cells, the CTL activity of mouse was observed in vivo.

RESULTSThe spleen lymphocyte proliferation stimulated by FLB2C cells was remarkably stronger than that by LA795 . FLB2C might stimulated the T lymphocyte to secrete IL-2 in vitro, but LA795 didn't. FLB2C cell could induce CTL activity in vivo and the induced CTL killed FLB2C cells and LA795 in vitro, with the killing rate of 34% and 25.3% respectively; while LA795 induced CTL killing rate being 10.5% and 12.25% respectively (P < 0.01).

CONCLUSIONSFLB2C can stimulate T cell immunity in vivo or in vitro. The effect of FLB2C is significantly stronger than that of LA795 . The results suggest that FLB2C may be used to treat lung cancer through improving immunity. This provides immunological basis for applying FLB2C as a vaccine to clinical use.