A novel Hodgkin's disease (HD) derived cell line, L1236, was established from the peripheral blood of a patient with advanced Hodgkin's disease. Analysis of immunoglobulin (Ig) gene rearrangements revealed a biallelic Ig heavy chain and a monoallelic Ig kappa light chain gene rearrangement, pointing to a B-lymphoid origin of these cells. No DNA of Epstein-Barr virus was detected in L1236. The cells expressed the HD-associated surface antigens CD30 and CD15 as well as the transferrin receptor (CD71). Cytogenetic analysis of early passages of L1236 cells revealed a grossly disordered karyotype including cytogenetic aberrations described previously in other HD-derived cell lines. The Hodgkin/Reed-Sternberg (H-RS) cell origin of L1236 cells is further confirmed by Kanzler et al (Blood 87:3429, 1996), who found identical Ig gene rearrangement sequences in L1236 cells and H-RS cells of the same patient's bone marrow. L1236 cells expressed antigens necessary for efficient antigen presentation to T cells including HLA class I and II, B7.1 and B7.2, as well as adhesion molecules ICAM 1 and LFA 3. The cells secreted the interleukins (IL)-6, -8, -10, tumor necrosis factor (TNF) alpha, interferon (IFN) gamma, transforming growth factor (TGF) beta, and the granulocyte-macrophage colony stimulating factor (GM-CSF). After subcutaneous inoculation into SCID mice, a necrotic regression of initially growing tumors at the injection site was followed by disseminated intralymphatic growth. Our findings, together with the results of Kanzler et al, demonstrate that H-RS cells of B-lymphoid origin were present in the peripheral blood of a patient with advanced HD. These cells exerted a malignant phenotype with regard to their in vitro and in vivo characteristics.

Plasmids carrying the Epstein-Barr virus (EBV) latent gene obtained with these EBV-based vectors were compared EBNA1 and the EBV latent origin of replication (oriP) stay with another plasmid, not carrying EBNA1 and oriP. cDNAs in transfected human cells as autonomously replicating coding for GM-CSF, IL6, TNF␣, the chloramphenicolacetylextrachromosomal genetic units. They thus might reptransferase (CAT) and the ␤-galactosidase (lacZ) gene resent a suitable tool for cytokine gene introduction into were transfected into the EBV-positive Burkitt's lymphoma human tumor cells with the prospect of therapeutic anticell line BL60 and the EBV-negative B cell lymphoma cell tumor vaccination. The aim of this study was to analyze line BJA-B. EBV-derived vectors permitted a high, host cell whether such plasmids permit stable and efficient independent transfection efficiency and high and host cell expression of cytokine genes in human non-Hodgkin lymindependent levels of expression. After removal of the phoma cells. We tested physical stability and expression selection pressure (hygromycin B) cytokine expression levels of plasmids carrying EBNA1 and oriP for episomal could be detected for several weeks in vitro and in vivo maintenance, immunoglobulin light chain enhancer but, however, declined continuously. These experiments elements for augmentation of expression, and cytokine or suggest that episomal BC-derived vectors represent an marker genes after introduction into human NHL cell lines effective tool for cytokine gene transfer in human lymin vitro and in vivo after inoculation into nude mice. Data phoma cells.

EBV-immortalized B-lymphoblastoid cell lines (LCL) inoculated s.c. into T-cell-deficient nude mice regress completely after a short initial growth period. We tested whether the putative host response underlying this phenomenon might also be directed against progressively growing Burkitt's lymphoma (BL) tumors in nude mice. Outgrowth of BL tumors was suppressed when cells of the highly tumorigenic BL cell line BL 60 were mixed with cells of the autologous LCL IARC 277 before s.c. inoculation into nude mice. Even when the cells were inoculated separately and simultaneously into contralateral flanks of the mice, regression of initially growing BL tumors could be observed, albeit with reduced frequency and dependent on the dose of LCL cells. Tumor growth of BL 60 cells could also be suppressed by co-inoculation with the non-autologous LCL IARC 174 and IARC 277 cells could suppress growth of the non-autologous BL cell line Eli. Pronounced infiltration with murine (m)CD-11b-positive mouse macrophages and mCD-8a-positive mouse lymphoid cells, most probably natural killer cells, was seen in histological tissue sections of regressing BL 60 tumors when LCL cells were inoculated contralaterally. In regressing BL tumors, these mouse cells were present not only in necrotic areas but also in vital BL tissue, indicating that infiltration of mouse cells had taken place before the development of necrosis. Since tumor-infiltrating mouse cells can be activated at least by some human cytokines, we measured cytokine production of BL 60 and IARC 277. High amounts of IL 6 and IL 10 were produced by the LCL cells, whereas IL-6 and IL-10 production by the BL 60 cells was beyond or close to the detection threshold. In addition, IL 8 was secreted up to 5-fold more by the LCL than by the BL cells. The results presented here thus suggest a host response of the nude mouse, which is triggered by cytokines released from the LCL but, once induced, is directed also against BL cells.

No abstract

Epstein-Barr virus (EBV)-