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.