Human B-Cell Interleukin-10: B-Cell Lines Derived From Patients With Acquired Immunodeficiency Syndrome and Burkitt’s Lymphoma Constitutively Secrete Large Quantities

A recent addition to the lymphokine network is human IL-10 (hlL-10). This novel lymphokine has striking homology to BCRFl protein, the product of a previously uncharacterized open-reading frame in the Epstein-Barr virus (EBV) genome. To date, IL-10 expression has been described in several T clones induced with antLCD3 and phorbol myristate acetate (PMA), in monocytes stimulated with lipopolysaccharide (LPS), and in murine B-cell lymphomas. We sought to determine whether human B cells express hlL-10 and, if so, its relationship to EBV and to other B-cell lymphokines. We studied 21 EBV-positive B-cell lines derived from patients with acquired immunodeficiency syndrome (AIDS) and Burkitt’s lymphoma (n = 6). American Burkitt’s (n = 3). African Burkitt’s (n = 5). and normal lymphoblastoid cell lines (n = 7). in comparison with seven EBV-negative cell lines. All cell lines were activated with the tumor promoters PMA and teleocidin and were studied by Northern blot analysis, reverse transcription-polymerase chain reaction (RT-PCR), and enzyme-linked immunoadsorbent assay (ELISA). We demonstrated that EBV-positive cell tines derived from patients with American Burkitt’s lymphoma, and especially those from patients with AIDS, constitutively express large quantities of hlL-10 by Northern blot analysis and ELISA (range, 3,101 t o 25,915 pg/mL), and that both teleocidin and‘PMA induce hlL-10 in these cell lines. In contrast, six of seven