Objective: To compare the efficiency of pamidronate (PAM) and isopentenyl pyrophosphate (IPP) to stimulate γδ T cell expansion from human peripheral blood and explore the optimized expansion conditions.
Methods: Peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll-Paque gradient centrifugation, and then cultured in RPMI1640 medium supplemented with 10% fetal bovine serum, IPP (1.0, 5.0, 10.0, 15.0 μg/mL) or PAM (2.0, 5.0, 8.0, 12.0 μg/mL), and IL-2 (100.0, 200.0, 500.0 IU/mL). The cells were observed and collected. The number and proportion of CD3⁺TCRδ2⁺ γδ T cells stimulated by PAM or IPP in total lymphocytes were evaluated by flow cytometry and the expansion efficiency was calculated.
Results: After 14 days, the ratios of γδ T cells in total lymphocytes in IPP group and PAM group increased to 81.3% and 78.5%, respectively. This indicated that both IPP and PAM could effectively stimulate γδ T cell expansion and there was no significant difference in the efficiency of expansion between the two groups (P>0.05).
Conclusion: PAM has the similar ability with IPP to stimulate γδ T cell expansion in vitro. PAM could become more economical and practical choice for stimulating γδ T cell expansion.