In vivoproduction of interleukin‐10 by malignant cells in AIDS lymphomas

摘要

AbstractExpression of the interleukin (IL)‐10/BCRF1 gene was studied byin situhybridization in tissue samples from acquired immunodeficiency syndrome (AIDS) lymphomas using a BCRF1 probe which also recognizes the human IL‐10 sequence. Hybridization was detected in 8 out of 15 lymphomas. In contrast, the IL‐10/BCRF1 gene expression was detected in only 1 out of 11 lymphomas from human immunodeficiency virus (HIV)‐seronegative patients (p= 0.05). In AIDS lymphomas, the number of cells labeled with a BCRF1‐specific probe was dramatically lower than that of cells labeled with the IL‐10/BCRF1 probe. Thus, the IL‐10 rather than the BCRF1 gene was expressed. Production of IL‐10 was associated with that of IL‐10 mRNA, as shown by immunodetection of the protein in numerous cells. In contrast, BCRF1‐producing cells were rarely detected. Bothin situhybridization and immunochemical experiments indicated that malignant cells were involved in this IL‐10 synthesis. IL‐10 production in AIDS lymphomas was associated with the presence of Epstein‐Barr virus (EBV) in lymphomatous cells (p= 0.02). As IL‐10 is a potent growth factor for human B lymphocytes, these results suggest that IL‐10 may stimulate the proliferation of malignant cells in an autocrine pathway in a number of AIDS lymphomas, and that EBV and HIV may synergist