Cytotoxicity ofγδT cells against methotrexate-resistant osteosarcoma U2OS cells / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the cytotoxic activities of γδT cells against methotrexate (MTX)-resistant osteosarcoma (OS) cells.Methods The MTX-resistant U2OS cell line (U2OS/MTX) was established by in vitro exposing the parental cells to MTX at stepwise-increasing concentrations.Periph-eral blood mononuclear cells ( PBMCs) were isolated from healthy subjects and stimulated with zoledronate ( ZOL) in combination with IL-2 to induce the proliferation ofγδT cells.The cytotoxicity ofγδT cells against U2OS/MTX cells was analyzed by using a standard lactate dehydrogenase release assay (LDH).Flow cy-tometry analysis and ELISA were performed to detect the expression of CD69 and IFN-γby γδT cells, re-spectively.Results The γδT cells derived from healthy subjects showed cytotoxicity against the U2OS/MTX cells.Moreover, stronger cytotoxic activities of γδT cells were detected after pretreatment of U2OS/MTX cells with ZOL (1 μmol/L) for 24 hours (P<0.01).Stimulation with U2OS or U2OS/MTX cells in-creased the expression of CD69 onγδT cells and enhanced the secretion of IFN-γbyγδT cells (P<0.05). Increased expression of CD69 and enhanced secretion of IFN-γwere induced in γδT cells in response to stimulation with ZOL-pretreated U2OS/MTX cells (P<0.01).Conclusion TheγδT cells showed cytotox-icity against U2OS/MTX cells.Pretreatment of U2OS/MTX cells with ZOL could enhance the cytotoxic ac-tivity of γδT cells.