title: Factor(s) released from irradiated B-CLL cells induce apoptosis in leukemic lymphocytes.
abstract: Photon irradiation of peripheral blood lymphocytes from 25 patients with untreated B-chronic lymphocytic leukemia (B-CLL) induced an increase in apoptotic response by 270%. No significant increase in apoptosis was observed after irradiation of peripheral blood mononuclear cells from 15 healthy volunteers. Supernatants (sups) derived from irradiated leukemic cells incubated with non-irradiated autologous cells induced a 75% enhancement in number of apoptotic cells, as compared with sups from non-irradiated CLL cells. The level of tumor necrosis factor alpha, a cytokine known to prevent apoptosis, was reduced in the sups of irradiated CLL cells in comparison to that of non-irradiated lymphocytes. The interleukin (IL)-10 level, an IL reported to induce apoptosis, was similar in the sups of irradiated and non-irradiated lymphocytes from B-CLL patients. No change in IL-2 levels was observed. The significance of these findings and the role of factor(s) in the sups of irradiated leukemic lymphocytes as inducers of apoptosis are discussed.
authors.affiliation: Laboratory for Immunology and Hematology Research, Rabin Medical Center, Golda Campus, Petah Tiqva and the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Hanna
authors.initials: H
authors.lastname: Bessler
authors.forename: Michael
authors.initials: M
authors.lastname: Bergman
authors.forename: Hertzel
authors.initials: H
authors.lastname: Salman
authors.forename: Amos M
authors.initials: AM
authors.lastname: Cohen
authors.forename: Eyal
authors.initials: E
authors.lastname: Fenig
authors.forename: Meir
authors.initials: M
authors.lastname: Djaldetti
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects; D005260:Female; D006131:Growth Inhibitors / Q000378:metabolism*; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism / Q000532:radiotherapy*; D008214:Lymphocytes / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D006131:Growth Inhibitors; D007376:Interleukin-2; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10