Analysis of transformation with Epstein-Barr virus and phenotypic characteristics of lymphoblastoid cell lines established from patients with hairy cell leukemia

Establishment of a new cell line from a patient with hairy cell leukemia-Japanese variant

A cell line, JHC-2, was established from the peripheral blood of a patient with hairy cell leukemia (HCL)-Japanese variant. The JHC-2 cells have cytologic features similar to those of the original tumor cells. They displayed hairy cytoplasmic projections by phase contrast and scanning electron microscopy. The tartrate-resistant acid phosphatase reaction was weakly positive. The immunophenotype of the JHC-2 cells was CD5-, CD10-, CD11c+/-, CD19+, CD21+, CD23+, CD24-, CD25+/-, CD38- and FMC-7+. The expression of surface immunoglobulin (IgG, kappa) and the configuration of Ig gene rearrangements in the JHC-2 cells were identical to those in the original leukemic cells, and the JHC-2 cells displayed trisomy 9 on cytogenetic examination. Southern blot analysis for the Epstein-Barr virus (EBV) genome showed that the JHC-2 cells contained the EBV genome, although the freshly isolated leukemic cells did not. These results indicate that the JHC-2 cell line is an EBV spontaneously transformed B cell line originating from HCL cells.

Establishment and characterization of a villous lymphoma cell line from splenic B-cell lymphoma

A new B-cell line (VL51) with cytoplasmic villi was established from a female patient with splenic lymphoma with circulating villous lymphocytes (SLVL). The patient exhibited a clinical picture characteristic of SLVL, including massive enlargement of the spleen. Tartrate-resistant acid phosphatase (TRAP)-negative villous lymphocytes were seen in the peripheral blood, bone marrow (BM) and both red and white pulps of the spleen. Monoclonality of the VL51 cell line was confirmed by clonal genotype abnormalities in the immunoglobulin heavy chain (IgH) gene and the T-cell receptor beta (TCR beta) gene. Evidence for commitment of phenotype of the VL51 cell line to the B lineage was also shown by the immunophenotype, including expression of CD10, CD19, CD20 and surface immunoglobins. The VL51 cells were positive for Epstein-Barr virus nuclear antigen (EBNA). The VL51 cell line is the first SLVL cell line to be established, and it is expected to be useful in clarifying the leukemogenesis of SLVL.

Lack of evidence of Epstein-Barr virus in hairy cell leukemia and monocytoid B-cell lymphoma

An association between the Epstein-Barr virus (EBV) and hairy cell leukemia (HCL) has been reported. Due to the similarities between HCL and monocytoid B-cell lymphoma (MBCL), an association between EBV and MBCL has been postulated. To address these issues we studied 27 spleens from cases with HCL and 13 tissue specimens from cases with MBCL from various sites for evidence of EBV DNA and RNA by in situ hybridization. Using a genomic EBV internal repeat probe and an oligonucleotide probe directed against the EBER1 gene, we were unable to identify EBV DNA or RNA, respectively, in the tumor cells of any of the cases. The results of our study suggest that EBV may not be strongly linked with either HCL or MBCL.

Deficient human immunodeficiency virus type 1-specific cytotoxic T cell responses in vertically infected children

Cytotoxic T lymphocyte (CTL) responses to human immunodeficiency virus type 1 (HIV-1) gag proteins were studied prospectively in 17 children (12 infected) born of mothers with HIV-1 seropositivity and in five pediatric patients with hemophilia infected by transfusion of HIV-1-contaminated factor VIII concentrate. B lymphoblastoid cells infected with vaccinia virus vectors expressing HIV-1 gag gene products were combined with autologous peripheral blood mononuclear cells to detect circulating CTLs. Effector cells were defined by monoclonal antibody-mediated, complement-dependent cytolysis. Circulating HIV-1 gag-specific cytotoxic responses were detectable in 4 of 5 HIV-1-infected pediatric hemophilic patients, and were similar in magnitude to those previously described in adults. In contrast, circulating HIV-1 gag-specific cytolysis was detectible in only 3 of 12 vertically infected children. Depletion data revealed that the majority of detectible gag-specific cytolysis was CD8 T cell-mediated. No apparent relationships between CD4 T cell counts, CD8 T cells counts, or serum p24 antigen levels and CTL responses were seen. Deficient CTL development may, in part, explain the more rapid onset of symptomatic disease following vertical HIV infection.

Predilection of a nasopharyngeal carcinoma-derived isolate of Epstein-Barr virus for infection of specific subsets of B lymphocytes

It is important to know whether there are variants of Epstein-Barr virus (EBV) with biological properties that are different from the prototype viruses that have been studied in detail, such as P3HR-1 and B95-8. We have studied an EBV isolate derived from a nasopharyngeal carcinoma (NPC) tumor, designated NPC-EBV. We have examined the target B lymphocytes infected and growth-transformed with NPC-EBV as compared with two common EBV isolates, B95-8 and AG876 EBV, for stage of maturation using antibodies to several immunoglobulin chains. Typing of the NPC-EBV transformed lymphoblastoid cell lines revealed the predilection of the NPC-EBV isolate to infect immature B lymphocytes. This was not the case for the B95-8 and AG876 isolates. The reason for the predilection of NPC-EBV for immature B lymphocytes remains to be explored further. However, these results may be important in understanding the pathophysiology of EBV-associated diseases.

New cell line from hairy-cell leukemia: confirmation of leukemic cell origin by karyotype and Ig gene analysis

A hairy-cell leukemia (HCL) line, BNBH-I, was established from the peripheral blood of a 40-year-old male patient with HCL in a relatively stable clinical phase after splenectomy. The cells have since been growing continuously for more than 2 years. Their cell surface immunoglobulin (sIg) was identical with that found on the surface of freshly isolated leukemic cells, consisting of IgG-kappa. The BNBH-I cells were more mature than the original hairy cells in their degree of B-cell differentiation, as reflected by a decrease in sIg expression together with the appearance of some cytoplasmic Ig (cIg)+ cells, loss of EA gamma-rosette formation and reactivity with monoclonal antibody (MAb) FMC7, and an increase in the proportion of MAb PCA-I+ cells. The BNBH-I cells possessed the antigen recognized by Leu-M5, a highly specific MAb for HCL. Epstein-Barr virus nuclear antigen (EBNA) was present. Both the freshly isolated leukemic cells and the cell line had the 14q+ involving q32 chromosomal abnormality, and their Ig gene rearrangements were also identical. Following exposure to 12-O-tetradecanoylphorbol-13-acetate (TPA), both the freshly isolated leukemic cells and the BNBH-I cells adhered to culture dishes and extended long, thin processes, a phenomenon characteristic of HCL. These results indicate that the BNBH-I line was derived from the leukemic hairy cells.

Phenotypic changes associated with chemically induced differentiation of a hairy cell leukemia cell line

In vitro chemically induced differentiation of the JOK-1 cell line, derived from a patient with hairy cell leukemia, has been studied. Non-induced JOK-1 cells expressed sIgM, B-1, CALLA, Ia, and C3 receptors. Following exposure to 2% DMSO, or 100 ng/ml 12-O-tetradecanoyl-phorbol-13-acetate (TPA), the cells underwent a phenotypic change from lymphoblastoid to monocytoid. In the presence of TPA, they became adherent and developed dendritic processes. Associated with these changes was a decrease in sIgM and CALLA and variable expression of C3 receptors. No monocyte/macrophage-associated antigens were detected. These results suggest that the JOK-1 cell line may have a limited ability to differentiate but is not mature enough to complete the differentiation process.

The 14q+ marker in hairy cell leukaemia. A cytogenetic study of 15 cases

Leukaemic cells from 19 patients with hairy cell leukaemia (HCL), characterised by morphological, immunological and ultrastructural criteria, were investigated for chromosome abnormalities after stimulation with B-cell mitogens (Pokeweed mitogen (PWM), lipopolysaccharide B and EBV). The cells from all cases had a B-cell phenotype and in each case only a single light chain type was expressed on the membrane of the cells. Only 15 patients with adequate metaphases are included in this study. Clonal chromosome abnormalities were observed in 12 patients of which five had a 14q + involving q32. Of the remaining 3 cases 1 had nonclonal abnormalities and 2 had normal karyotypes. The donor chromosomes were identified in 3 cases and were found to be 9, 18 and 22. An interstitial rearrangement of chromosome 14 involving band q22 was seen in 2 cases and a deletion of chromosome 14 at q24 in 1 case. Amongst other chromosome abnormalities 12p was involved in 4 cases, 12q in 2 cases and chromosomes 7 and 22 in 3 cases each. The significance of the abnormalities has been discussed in relation to sites of cellular oncogenes. Our study demonstrates that chromosome abnormalities common to other B-cell disorders are present in HCL.

Differential effect of TPA and n-butyrate on induction of Ii and EBV antigens in the P3HR-1 lymphoblastoid cell line

The aim of this study was to test whether EBV induction by TPA or n-butyrate was related directly to hyperexpression of Ii, an electrophoretically invariant, 35 000 dalton, HLA-DR antigen-associated glycoprotein which is abundantly detected in EBV freshly transformed cells and is enhanced by EBV superinfection of lymphoblastoid cell lines. P3HR-1 lymphoblasts were treated with n-butyrate or TPA in variable doses and durations. The augmented expression of Ii, EBV antigens (EA and VCA), DNA synthesis, and cell growth and viability were monitored. n-Butyrate induced hyperexpression of Ii at 2 days with a maximal effective dose of 4 mM, induced EBV antigens (EA and VCA) in 36 per cent of the cells at 2 days, inhibited DNA synthesis and cell growth, and was not cytolytic at 48 h when Ii induction was maximal. TPA did not induce hyperexpression of Ii, induced EBV antigens (EA) in 30 per cent of the cells at 4 days, did not inhibit DNA synthesis and cell growth, and was not cytolytic in the time course and doses studied. Ii expression, therefore, did not appear to be an obligatory consequence of EBV antigen induction. Ii induction might be related to an effect of EBV inducers on cellular DNA synthesis, or on control of the cell cycle, or directly upon Ii gene regulation.