High Epstein-Barr virus (EBV) susceptibility of both lymphoblastoid and lymphoma cell lines derived from a Japanese patient with EBV genome-positive Burkitt's lymphoma

Epstein-Barr virus (EBV) hypersensitivity of peripheral B lymphocytes in patients with EBV genome-positive Burkitt's lymphoma

Peripheral blood mononuclear cells (PBMC) from four Japanese patients with Epstein-Barr virus (EBV) genome-positive Burkitt's lymphoma (BL) during remission were exposed to the B95-8 strain of EBV. Maximum concentrations of the EBV-determined nuclear antigen (EBNA) before cellular DNA synthesis were similar to those of healthy counterparts. Subsequently, EBV-immortalised cell lines were established. These immortalised lymphoblastoid cells were treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) and superinfected with the P3HR-1 strain of EBV. EBV early antigens (EA) and viral capsid antigen (VCA) were expressed in approximately 3-10 fold higher concentrations by these lymphoblastoid cells than by those from patients with other types of malignant neoplasia including EBV genome-negative BL and from healthy counterparts. Moderate to extremely high IgG antibody titres to EBV VCA as well as IgG antibodies to EA were demonstrated in these patients during the study. These results suggest that defective underlying cellular mechanisms for regulating the replication of EBV may be present in patients with EBV genome-positive BL.

Decreased cytoplasmic immunoglobulin A production during Epstein-Barr virus immortalization on lymphocytes from patients with ataxia-telangiectasia

Previously, we have reported significantly lower immunoglobulin (Ig) A production in supernatants of cultured lymphoblastoid cells using enzyme-linked immunosorbent assay from patients with ataxia-telangiectasia (AT) when compared to that of age- and sex-matched healthy individuals. Here, we further assess the degree of cytoplasmic Ig production in these cells and also analyze it during the early phase of Epstein-Barr virus immortalization. All classes of cytoplasmic IgM, IgG, and IgA productions were demonstrated in cells from healthy controls. In contrast, cells from patients with AT showed only cytoplasmic IgM and IgG with low or nondetectable levels of IgA during and after the immortalizing process. These results suggest B lymphocytes bearing IgA are functionally immature and/or defective in patients with AT.