[The promoting effects of mGM-CSF gene modified tumor vaccine immunization on peritoneal antigen presenting cells in mice].
To investigate the effects of immunization with granulocyte-macrophage colony-stimulating factor (GM-CSF) gene-modified tumor vaccine on the number and function of antigen presenting cells (APCs). FBL-3 murine erythroleukemia cells were transfected with mGM-CSF recombinant adenovirus and then irradiated to prepare vaccine. The specific cytotoxic T lymphocyte(CTL) activity in vivo and survival of the mice i.p. immunized with this vaccine were observed. The percentage of 33D1+ dendritic cells(DCs) in peritoneal adherent cells were analyzed with flow cytometry. The number of peritoneal cell and function of peritoneal adherent cells of immunized mice were also investigated. High level of specific CTL activity were induced in the mice i.p. immunized with this vaccine and all of the mice were resistant to the subsequent challenge with the parental FBL-3 cells. The number of peritoneal APCs-increased. FACS analysis showed that the percentage of 33D1+ DCs in peritoneal adherent cells also increased. The allo-mixed lymphocyte reaction(MLR) stimulating activity of these APCs was enhanced. mGM-CSF gene-modified tumor vaccine has potent anti-tumor effect, and this may be related to the increased number and function of peritoneal APCs induced by mGM-CSF through paracrine mechanism at the vaccination site.