title: Proteomic comparison of 3D and 2D glioma models reveals increased HLA-E expression in 3D models is associated with resistance to NK cell-mediated cytotoxicity.
abstract: Three-dimensional cell culture techniques can better reflect the in vivo characteristics of tumor cells compared with traditional monolayer cultures. Compared with their 2D counterparts, 3D-cultured tumor cells showed enhanced resistance to the cytotoxic T cell-mediated immune response. However, it remains unclear whether 3D-cultured tumor cells have an enhanced resistance to NK cell cytotoxicity. In this study, a total of 363 differentially expressed proteins were identified between the 2D- and 3D-cultured U251 cells by comparative proteomics, and an immune-associated protein-protein interaction (PPI) network based on these differential proteins was constructed by bioinformatics. Within the network, HLA-E, as a molecule for inhibiting NK cell activation, was significantly up-regulated in the 3D-cultured tumor cells. Then, we found that the 3D-cultured U251 cells exhibited potent resistance to NK cell cytotoxicity in vitro and were prone to tumor formation in vivo. The resistance of the 3D-cultured tumor cells to NK cell lysis was mediated by the HLA-E/NKG2A interaction because the administration of antibodies that block either HLA-E or NKG2A completely eliminated this resistance and significantly decreased tumor formation. Taken together, our findings indicate that HLA-E up-regulation in 3D-cultured cells may result in enhanced tumor resistance to NK cell-mediated immune response.
authors.affiliation: Department of Neurosurgery, General Hospital of People's Liberation Army Chengdu Military Region, Chengdu 610083, China.
authors.forename: Weiqi
authors.initials: W
authors.lastname: He
authors.forename: Yongqin
authors.initials: Y
authors.lastname: Kuang
authors.forename: Xuemin
authors.initials: X
authors.lastname: Xing
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Simpson
authors.forename: Haidong
authors.initials: H
authors.lastname: Huang
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.forename: Jingmin
authors.initials: J
authors.lastname: Chen
authors.forename: Libin
authors.initials: L
authors.lastname: Yang
authors.forename: Enyu
authors.initials: E
authors.lastname: Liu
authors.forename: Weifeng
authors.initials: W
authors.lastname: He
authors.forename: Jianwen
authors.initials: J
authors.lastname: Gu
mesh_terms: D000818:Animals; D019138:Antibodies, Blocking / Q000276:immunology / Q000494:pharmacology; D015153:Blotting, Western; D018929:Cell Culture Techniques / Q000379:methods*; D045744:Cell Line, Tumor; D002853:Chromatography, Liquid; D003602:Cytotoxicity, Immunologic / Q000187:drug effects / Q000276:immunology*; D015870:Gene Expression / Q000276:immunology; D005910:Glioma / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008954:Models, Biological; D055654:NK Cell Lectin-Like Receptor Subfamily C / Q000276:immunology / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects / Q000276:immunology; D060066:Protein Interaction Maps / Q000276:immunology; D040901:Proteomics / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053719:Tandem Mass Spectrometry; D023041:Xenograft Model Antitumor Assays / Q000379:methods; D000097625:HLA-E Antigens
chemical_list: D019138:Antibodies, Blocking; D015395:Histocompatibility Antigens Class I; D055654:NK Cell Lectin-Like Receptor Subfamily C; D000097625:HLA-E Antigens