Büssing A, Stein G M, Pfüller U, Schietzel M
Department of Applied Immunology, University Witten/Herdecke, Communal Hospital, Germany.
Anticancer Res. 1999 May-Jun;19(3A):1785-90.
Fas ligand (FasL, CD95L) predominantly expressed on activated cytotoxic T cells and NK cells triggers apoptosis in Fas receptor (Apo-1, CD95) positive target cells. We investigated the expression of FasL, Fas and tumor necrosis factor (TNF) receptor 1 (TNF-R1, CD120a) on cultured human lymphocytes and leukemic T and B cells.
Lymphocytes from six healthy individuals, from four patients with chronic lymphocytic T or B cell leukaemia, and leukemic Molt-4 cells were incubated with the apoptosis- inducing mistletoe lectins (ML I and ML III).
Incubation of differentiated lymphocytes with the ML resulted in a significant upregulation of FasL in the surviving CD4+ T helper cells, CD8+ cells and CD19+ B cells. Similarly, the TNF receptor expression increased, while the Fas molecule decreased. In contrast, FasL was not induced in leukemic cells.
Apart from a direct induction of apoptosis in response to an inhibition of protein synthesis by the enzymic ML A chain, ML treatment may indirectly induce apoptosis in Fas+ tumour cells through activated FasL+ lymphocytes.
主要表达于活化的细胞毒性T细胞和自然杀伤细胞上的Fas配体（FasL，CD95L）可触发Fas受体（Apo-1，CD95）阳性靶细胞的凋亡。我们研究了培养的人淋巴细胞、白血病T细胞和B细胞上FasL、Fas和肿瘤坏死因子（TNF）受体1（TNF-R1，CD120a）的表达情况。
将来自6名健康个体、4名慢性淋巴细胞性T或B细胞白血病患者的淋巴细胞以及白血病Molt-4细胞与诱导凋亡的槲寄生凝集素（ML I和ML III）一起孵育。
用ML孵育分化的淋巴细胞后，存活的CD4⁺辅助性T细胞、CD8⁺细胞和CD19⁺B细胞中FasL显著上调。同样，TNF受体表达增加，而Fas分子减少。相反，白血病细胞中未诱导出FasL。
除了通过ML的酶A链抑制蛋白质合成直接诱导凋亡外，ML治疗可能通过活化的FasL⁺淋巴细胞间接诱导Fas⁺肿瘤细胞凋亡。
