title: Aberrant expression of HLA class-I antigens in Burkitt lymphoma cells.
abstract: HLA class-I expression has been investigated by biochemical methods in 14 Burkitt lymphoma (BL) cell lines and the corresponding Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL) derived from the same individuals. Selective down-regulation of one or more HLA class-I specificities was demonstrated in 9 out of 14 BL lines. The defect was restricted to a single HLA-A allele in 3 of the lines (BL29, BL72, WW-I-BL). Four lines (BL28, BL37, BL41 and Jijoye M13) showed down-regulation of both HLA-A and -C alleles, and one (BL36) failed to express one HLA-C allele. Only one BL line (WW-2-BL) had lost one HLA-A and one HLA-B allele. The allele-specific defects were mainly detected in cell lines that had maintained the phenotypic characteristics of the original tumor. Expression of B-cell activation markers and the EBV-encoded nuclear antigen (EBNA)-2 correlated with up-regulation of the Cw4 allele in the P79 subline of the BL line Jijoye. Treatment with gamma-interferon (IFN) resulted in full or partial reversion of the HLA class-I defects in some of the cases but had no significant effect in others. This was not due to a cell-line-related unresponsiveness to IFN, nor did it reflect an allele-specific mode of regulation because the same allele could respond differently in different cell lines. The data suggest that defective expression of HLA class-I antigens, which appears to be more prevalent for alleles within the HLA-A and -C loci, is a common feature of BL cell lines. Different regulatory mechanisms appear to be involved.
authors.affiliation: Dept. of Tumor Biology, Karolinska Institute, Stockholm, Sweden.
authors.forename: M L
authors.initials: ML
authors.lastname: Andersson
authors.forename: N J
authors.initials: NJ
authors.lastname: Stam
authors.forename: G
authors.initials: G
authors.lastname: Klein
authors.forename: H L
authors.initials: HL
authors.lastname: Ploegh
authors.forename: M G
authors.initials: MG
authors.lastname: Masucci
mesh_terms: D000483:Alleles; D000956:Antigens, Viral / Q000032:analysis; D002051:Burkitt Lymphoma / Q000276:immunology*; D019309:Epstein-Barr Virus Nuclear Antigens; D016259:Genes, myc; D015395:Histocompatibility Antigens Class I / Q000032:analysis* / Q000235:genetics; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D010641:Phenotype; D014407:Tumor Cells, Cultured
chemical_list: D000956:Antigens, Viral; D019309:Epstein-Barr Virus Nuclear Antigens; D015395:Histocompatibility Antigens Class I; D007371:Interferon-gamma