title: Stable expression of EBV-gp350 on the surface of NC37 cells confers natural killer (NK)-cell susceptibility or resistance, depending on the assay used to assess NK-mediated function.
abstract: NC37 cells containing the Epstein-Barr virus (EBV) genome do not express the viral glycoprotein-350 (gp350) on the cell surface. Despite being a cancer cell line, NC37 cells show resistance to natural killer (NK) cell cytotoxicity by the standard chromium ((51)Cr) release assay (CRA). EBV-gp350 has been identified as a ligand for antibody dependent cell-mediated cytotoxicity (ADCC). The stable expression of gp350 on the NC37 cell surface membrane could make this cell line a suitable target for measuring ADCC antibody. The pcDNA3.1-gp350 was transfected into the stably expressing enhanced green fluorescent protein (EGFP)-NC37 cell line. The transfected cells were then selected for expression of gp350 on the cell surface using immunomagnetic bead-based sorting. The gp350-EGFP-NC37 cell line was then re-examined for resistance to NK cytotoxicity, and compared with the standard K562 and EGFP-K562 cell lines using the CRA and a flow cytometric method, respectively. Surprisingly, the gp350-EGFP-NC37 cells, like the parental NC37 cell line, showed comparable resistance to NK cell-mediated cytotoxic activity by the CRA, while demonstrating susceptibility to NK cell cytotoxicity comparable to EGFP expressing K562 cells by the flow cytometric method. The susceptibility of gp350-EGFP-NC37 cells to NK cell cytotoxic activity is dependent on the type of assay.
authors.affiliation: Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Manutsanun
authors.initials: M
authors.lastname: Sumonwiriya
authors.forename: Navin
authors.initials: N
authors.lastname: Horhthongkham
authors.forename: Kovit
authors.initials: K
authors.lastname: Pattanapanyasat
authors.forename: Silawun
authors.initials: S
authors.lastname: Ampol
authors.forename: Reungpung
authors.initials: R
authors.lastname: Sutthent
authors.forename: Wannee
authors.initials: W
authors.lastname: Kantakamalakul
mesh_terms: D045744:Cell Line, Tumor; D002860:Chromium Radioisotopes / Q000378:metabolism; D003601:Cytotoxicity Tests, Immunologic / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D014763:Viral Matrix Proteins / Q000096:biosynthesis* / Q000276:immunology*
chemical_list: D002860:Chromium Radioisotopes; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D014763:Viral Matrix Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins