Effect of RetroNectin on the proliferation of CIK cells and the possible mechanisms

Objective:To investigate the effect of RetroNectin on CIKs cells and the related mechanisms. Methods:Peripheral blood mononuclear cells (PBMC) were collected from patients and divided into two groups:group Ⅰ and group Ⅱ.Samples in group Ⅰ were seeded into culture flask precoated with RetroNectin and CD3mAb to induce CIKs.While samples in group Ⅱ were seeded into common culture flask.The proliferation of CIKs was detected by cytometric analysis.The cytotoxic activity of CIKs was determined by LDH assays.The phenotype changes and cell cycle of CIKs were identified by flow cytometry.The apoptosis of cells was detected by Annexin V/PI.Western blot was employed to detect the level of protein Vav1.The CD49d and CD49e were blocked by anti-CD49d and anti-CD49e and the proliferation of cells was tested by cytometric analysis after the blockage.The phenotype changes of cells were identified by flow cytometry after the blockage.Results:RetroNectin enhanced the proliferation of CIKs (P0.05).Flow cytometric analysis showed that RetroNectin significantly increased the number of CD25+ T cells (P0.05).RN-CIK was more active than CIK in killing HCT-8 cell lines in vitro (P0.05).RetroNectin could block the CIKs at G_1 phase (P 0.05) and resist apoptosis.There was no significant difference in the proliferation between the two groups after the blockage with CD49d and CD49e (P0.05).The expression of protein Vav1 was associated with CD25+T cells.Conclusion:RetroNectin enhances the proliferation of CIKs by influencing the cell cycle,resisting apoptosis possibly through the site of CD49d and CD49e,and inducing T cell activation as the second signaling through Vav1.