Apoptosis and Secondary Necrosis of Lymphocytes in Culture

Abstract

It has been reported that cultured peripheral B lymphocytes of chronic lymphocytic leukemia (B-CLL) patients show a high degree of apoptosis (programmed cell death). Till now, no data exist about the occurrence of in vitro apoptosis of normal B and T cells. We measured the amount of apoptosis and secondary necrosis (type 2 necrosis) in B-CLL lymphocytes and in normal peripheral B and T lymphocytes in culture. Observations were made on B-CLL lymphocytes and on normal B and T cells purified by immunomagnetic cell sorting. Apoptosis and secondary necrosis were measured using a recently described sensitive flow-cytometric assay, probing simultaneously for cell surface exposure of phosphatidylserine with the use of FITC-labeled annexin-V and for cell membrane integrity as demonstrated by the exclusion of propidium iodide. The degree of in vitro apoptosis and secondary necrosis of normal B cells appears to be higher than that of normal T cells, and even higher than that of B-CLL cells. The results indicate that cultured mature circulating normal B lymphocytes exhibit a higher cell death rate than normal T cells and B-CLL lymphocytes.

Acinar Cell Hypertrophy, Proliferation and Cell Death in Rat Submandibular Glands Induced by Long-Term Isoproterenol Administration.

“…Ultrastructurally, the cytoplasm was electron-lucent and was highly edematous, the cytoplasmic organelles had dissolved, and only the plasma membranes and mitochondria remained intact. Therefore, we have tentatively concluded that these types of cell death are morphologically analogous to "necrosis", even if the initial characteristics resemble "apoptosis", and consequently, this cell death without mitochondrial lysis is envisaged as "secondary necrosis" [17,23,38].…”

“…Hong et al [17] and Kroemer et al [23] proposed that it is the entity of cell death which primarily becomes apoptotic and then induces necrosis, and they refer to this process as "secondary necrosis" in order to distinguish it from classical types of the necrosis. Vermes et al [38] proposed the term "putrosis" to designate the same post-apoptotic status. We were able to detect three types of TUNEL-positive cells; 1) TUNEL-positive cells with pycnotic nuclei but without cytoplasmic lysis, similar to the classical type of apoptotic cell, 2) TUNEL-positive cells with blebbed peculiar nuclei located in and between the acinar cells, which resembled the "degenerating apoptotic bodies", and 3) TUNEL-positive cells with completely lysed cytoplasm.…”

Impaired uptake of apoptotic cells into tingible body macrophages in germinal centers of patients with systemic lupus erythematosus

“…During the late phases of apoptosis, membrane integrity cannot be maintained, resulting in leakage of intracellular antigens (39)(40)(41). In this way, potential autoantigens may become accessible to the immune system.…”

Fludarabine-mediated suppression of the excision repair enzyme ERCC1 contributes to the cytotoxic synergy with the DNA minor groove crosslinking agent SJG-136 (NSC 694501) in chronic lymphocytic leukaemia cells

“…Apoptosis was assessed by dual-colour immunofluorescent flow cytometry as described previously (Vermes et al, 1997;Pepper et al, 2003).…”