Shirou Fukuhara

Dispersed localization of D segments in the human immunoglobulin heavy-chain locus.

We have studied the organization of the human immunoglobulin heavy‐chain genes by pulse field gel electrophoresis as well as by isolation of cosmid clones. The total length of the heavy‐chain variable region locus was estimated to be approximately 3000 kb. We found that D segments including a recently isolated D5 segment were dispersed among VH segments. We identified a pseudo V segment 18 kb 3′ to the D5 segment in isolated cosmid clones. A 300 kb fragment produced by MluI digestion contained VH, D, JH segments and the distance between VH and D was estimated to be approximately 240 kb. Overlapping cosmid clones containing the human D1, D2, D3, D4, JH, Cmu and C delta genes were isolated. Restriction maps of these regions indicated that the distance between D and JH is about 22 kb. A partial restriction map of the VH locus was constructed using the pulse field gel electrophoresis technique and deletion of VH segments in B cells.

Cytogenetic studies on the adult T-cell leukemia in Japan

Cytogenetic studies were performed on 16 patients with ATL seen in Northern Kyushu island; nine were patients with acute type leukemia, one with crisis type and five with lymphoma type. The serum antibody for HTLV-1 (ATLA) was positive in all patients and the phenotype of ATL cells were ERFC+, OKT3+, OKT4+, OKT6-, OKT8-, OKT10+, OKla1+/- and Tac+. Abnormal findings of chromosomes were observed in 15 patients. Thirteen patients were in near diploid range. One patient was in triploid range and one patient was in tetraploid range. The polyploid karyotypes were found only in lymphoma type patients. Trisomy 3 and trisomy 7 were observed each in three patients with acute type of ATL. The most frequent abnormal rearrangement was observed in the long arm of chromosome 6 and the break occurred at band 6q15 and 6q21 each in four patients in this series.

A Novel B Cell Line Established from Ki-1-positive Diffuse Large Cell Lymphoma

A novel cell line, designated KIS‐1, was established from a patient with Ki‐1‐positive diffuse large cell lymphoma. Multiple phenotypic analysis of the KIS‐1 cells was carried out with a total of 22 monoclonal antibodies defining hematopoietic cell subsets and lineages. The KIS‐1 cells were positive for Ki‐1, B4, HLA‐DR, and 2D1 (common leucocyte) antigens, but were negative for the antigens reportedly specific for T cells, natural killer cells, granulocytes, monocytes, interdigitating reticulum cells and dendritic reticulum cells. The genomic analysis of the KIS‐1 cells showed not only the rearrangement of JH and Jk genes but also the probable rearrangement of Cγ genes. Moreover, the cells produced immunoglobulin γ chains. Thus, KIS‐1 was considered to be of B‐cell lineage. The lymphoma‐cell derivation of KIS‐1 was based on the following facts. The cytochemical, immunologic, cytogenetic properties and the results of the molecular genomic analysis in the KIS‐1 cells were essentially the same as those of the original tumor cells, and the KIS‐1 cells were negative for Epstein‐Barr virus‐associated nuclear antigen. KIS‐1 is the only known B‐cell line derived from Ki‐1‐positive diffuse large cell lymphoma, and should be useful for defining the biological implications of Ki‐1 antigen.

A newly established human acute lymphoblastic leukemia cell line with characteristics of the earliest B-cell maturation

SummaryA new human acute lymphoblastic leukemia (ALL) cell line, designated HBL-3, was established from the bone marrow of a patient with non-T-ALL. The HBL-3 cell line expressed B4 (CD 19), BA-1 (CD 24) and HLA-DR antigens, but not surface immunoglobulin (SIg) or cytoplasmic immunoglobulin (CIg). The cell line lacked the common acute lymphoblastic leukemia antigen (CALLA) and antigenic markers characteristic of T-cell and myeloid cell lineages. The HBL-3 cells had structural rearrangements of both the homologous chromosome 9s, including a translocation with chromosome 1 which has been reported in a patient with common ALL. The cell line had rearranged immunoglobulin heavy chain genes but retained germ-line κ light chain genes and germ-line T-cell receptorβ- and γ-chain genes. The HBL-3 cell line was strongly positive for terminal deoxynucleotidyl transferase (TdT). These findings indicate that the HBL-3 cell line is derived from the earliest B-cell committed to B-cell lineage.

A New Hypothesis on the Cellular Origin of Reed-Sternberg and Hodgkin Cells Based on the Immunological and Molecular Genetic Analysis of the KM-H2 Line

Previously we reported a novel cell line, KM-H2, established from the pleural effusion of a patient who was initially diagnosed as having Hodgkin’s of mixed cellular type (Kamesaki et al. 1986). We describe here the results of further investigation of this line (ultrastructural, immunological, and molecular genetic studies) and discuss its cellular origin. Based on these analyses of the KM-H2 line, as well as those of other cell lines derived from Reed-Sternberg and Hodgkin cells (e.g., L428, L540), we propose a new hypothesis for the cellular origin of Hodgkin’s disease.

Involvement of c-myc oncogene in lymphoma cell lines with no detectable chromosome rearrangement of band 8q24☆

Two lymphoma cell lines of B-cell type were established from Japanese patients with diffuse small noncleaved cell lymphoma. Cytogenetic analysis revealed a 14q+ marker chromosome in both cell lines, and a t(8;14)(q24.1;q32.3) seemed most likely to have occurred. The chromosome 8 pair, however, had no abnormalities. Molecular analysis demonstrated c-myc amplification lacking gross rearrangement in one cell line and genetic rearrangement of c-myc at the first intron as well as aberrant sizes of c-myc mRNA in the other cell line. In the latter case, it is possible that a t(8;14)(q24.1;q32.3) was buried in an unrecognized complex translocation. A combination of cytogenetic and molecular studies to determine the precise nature of the 14q32 translocation is discussed.