A Hodgkin's disease cell line, KM-H2, shows biphenotypic features of dendritic cells and B cells

The origin of Reed-Sternberg (RS) cells, the neoplastic cells of Hodgkin's disease, has long remained controversial. Dendritic cells (DCs) are highly specialized antigen-presenting cells that have the unique capacity to prime naive T cells, and they may be progenitors of RS cells in a population of Hodgkin's disease cells. In this study, the KM-H2 cell line, previously est ablished from a patient with Hodgkin's disease of mixed cellularity, was re evaluated for its cellular derivation, particularly in terms of DCs. KM-H2 cells were demonstrated to carry the newly proposed DC-associated molecules fascin, CD83, and DEC-205, as well as costimulatory molecules such as CD40 , CD80, and CD86. In addition. KM-H2 cells were shown to be able to potentl y stimulate peripheral blood T cells and to have the strong endocytotic act ivity of fluorescein isothiocyanate-dextran. On the other hand. KM-H2 cells were shown to have variable-diversity-joining recombination of the immunog lobulin H gene, although they did not express any subclasses of immunoglobu lin and they were negative for CD79a and CD79b. In addition, KM-H2 cells pr oduced the messenger RNA of the Pax-5 gene. These findings lead to a hypoth esis that KM-H2 cells originated from the cells that had differentiated thr ough the possible common DC-B-cell progenitors along the newly proposed pat hway. (C) 2001 The Japanese Society of Hematology.