title: Expression of HLA class I, beta(2)-microglobulin, TAP1 and IL-10 in Epstein-Barr virus-associated nasal NK/T-cell lymphoma: Implications for tumor immune escape mechanism.
abstract: Several mechanisms of immune escape might be in operation in Epstein-Barr virus (EBV)-associated nasal NK/T-cell lymphoma. We have previously shown the downregulation of the immunogenic EBV nuclear antigens by alternative promoter usage and the preferential selection of the deletion genotype of latent membrane protein 1 in nasal lymphoma. To understand further the strategies used for immune escape by this tumor, we examined by immunohistochemistry HLA class I expression in 15 cases using frozen sections, along with beta(2)-microglobulin and transporter associated with antigen processing 1 (TAP1) expression in 39 cases using paraffin sections. All nasal NK/T-cell lymphomas showed positive staining for HLA class I, beta(2)-microglobulin and TAP1 on most tumor cells, except for two cases (5%) in which most of the tumor cells lacked beta(2)-microglobulin staining. We next immunostained for interleukin-10 on frozen sections in 13 cases, all of which showed strong expression by most tumor cells. Transcription of human interleukin-10 but not EBV BCRF1 (viral interleukin-10) was identified by reverse transcriptase-polymerase chain reaction in these nasal NK/T-cell lymphomas. Overall, our data suggest that global downregulation of HLA class I or TAP1 rarely accounts for the ability of nasal NK/T-cell lymphoma to evade immunosurveillance and that other immune escape mechanisms may be operating in nasal NK/T-cell lymphoma, such as production of interleukin-10 to suppress the local immune response.
authors.affiliation: Department of Pathology, The University of Hong Kong, Queen Mary Hospital Compound, 102 Pokfulam Road, Hong Kong, ROC.
authors.forename: L
authors.initials: L
authors.lastname: Shen
authors.forename: A K
authors.initials: AK
authors.lastname: Chiang
authors.forename: W P
authors.initials: WP
authors.lastname: Liu
authors.forename: G D
authors.initials: GD
authors.lastname: Li
authors.forename: R H
authors.initials: RH
authors.lastname: Liang
authors.forename: G
authors.initials: G
authors.lastname: Srivastava
mesh_terms: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters / Q000032:analysis*; D020031:Epstein-Barr Virus Infections / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D016753:Interleukin-10 / Q000032:analysis*; D016399:Lymphoma, T-Cell / Q000276:immunology*; D009669:Nose Neoplasms / Q000276:immunology*; D001613:beta 2-Microglobulin / Q000032:analysis*
chemical_list: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters; D015395:Histocompatibility Antigens Class I; C073119:TAP1 protein, human; D001613:beta 2-Microglobulin; D016753:Interleukin-10