Th-1 drift induced by glioma cell vaccine with high immunogenicity in vitro

Objective To observe Th-1 drift induced in vitro by high immunogenic glioblastoma multiforme (GBM) U251 cell vaccine with high expression of membrane-enriched heat shock protein 70 (Hsp70) and major histocompatibility complex class Ⅰ (MHC-Ⅰ) molecules. Methods The high expression of MHC-Ⅰ and Hsp70 in U251 cells were induced by 500 U/ml IFN-γ for 48 h, heat shock at 43 ℃ for 2 h, or their combination. The cells were then inactivated by the mitomycin C (MMC) to prepare the cell vaccine. Peripheral blood mononuclear cells (PBMCs) from healthy donators were incubated with GBM U251 cell vaccines as the effector cells. Flow cytometry was applied to analyze the changes of CD4 and CD8 T lymphocytes in the PBMCs. The secretion of IFN-γ and IL-2 of the effector cells, after assaulting the target cells, was evaluated by ELISA. Results The percentages of CD4 and CD8 T lymphocytes of the PBMCs incubated with the U251 cell vaccine increased significantly as compared to that stimulated by the membrane-enriched MHC class Ⅰ or Hsp 70 molecule U251 cell vaccines (P<0.05), and so was the secretion of IFN-γ and IL-2 (P<0.05). Conclusions Th-1 drift stimulated by GBM U251 cell vaccine with high immunogenicity, high expression of Hsp 70 and membrane-enriched MHC class Ⅰ molecules plays an important role in antitumor mechanism in vitro. Key words: U251 cells; Major histocompatibility complex class Ⅰ; Membrane-enriched heat shock protein 70; Immunotherapy; Th-1 cells; Th-2 cells