Immortalized Epstein-Barr virus-positive B-cell lines obtained by prolonged culture of peripheral blood mononuclear cells from human immunodeficiency virus type 1-positive patients

Objectives: To study the factors that determine malignant B cell growth in human immunodeficiency virus type 1 (HIV-1)-infected patients. Study Design: B-cell lines (lymphocyte cell lines [LCL]) were developed after nonstimulated culture of peripheral blood mononuclear cells (PBMC) from HIV-1-positive (HIV-1(+)) patients. Human immunodeficiency virus type I replication in culture, Epstein-Barr virus (EBV) latent oncogene expression, and cell-to-cell interaction were studied after nonstimulated culture of HIV-1(+) PBMC, analyzing their contribution to LCL appearance. Methods: Nonstimulated PBMC cultures of HIV-1+ PBMC and controls (N-PBMC) were established. Lymphocyte cell lines were characterized. Epstein-Barr virus latent membrane protein 1 (LMP-1) and Epstein-Barr nuclear antigen 2 were detected by polymerase chain reaction (PCR). Clonality of LCL was determined by light chain restriction (flow cytometry) and immunoglobulin H chain rearrangement (semi-nested PCR). Peripheral blood mononuclear cell phenotypes were studied at different intervals of culture, Results: Lymphocyte cell lines were obtained in 73% of HIV-1(+) PBMC cultures, compared with 6% in N-PBMC. Ali LCL were EBV-positive (EBV+). B-cell lineage was established, and up to 12 different B-cell clones were expanded from the same individual. Occurrence of LCL was more frequent in cultures with HIV-1 replication, high LMP-1 expression in viable B cells, and high CD4:CD8 ratio. Human immunodeficiency virus type 1 replication persisted in 53% of the LCL. Conclusions: In vitro HIV-1 replication and persistence of viable EBV+ lymphoblasts favor spontaneous in vitro outgrowth of LCL in HIV-1(+) patients.