TY - JOUR
T1 - Apoptosis as a mechanism of lectin-dependent monocyte-mediated cytotoxicity
AU - Dong, Hai Dong
AU - Kimoto, Yasuhiko
AU - Takai, Shin Ichiro
AU - Taguchi, Tetsuo
PY - 1996
Y1 - 1996
N2 - In this study we investigated the mechanisms of cytotoxicity mediated by pokeweed mitogen (PWM)-activated human peripheral blood monocytes. By using DNA electrophoresis and propidium iodide (PI)-DNA staining flow cytometry, we demonstrated that apoptotic cell death of target U937 cells and Raji cells was induced in lectin (PWM)-dependent monocyte-mediated cytotoxicity (LDMC). The LDMC-mediated DNA fragmentation in U937 cells and Raji cells was induced in lectin (PWM)-dependent monocyte mediated cytotoxicity(LDMC). The LDMC- mediated DNA fragmentation in U937 cells was completely inhibited by anti- TNFα monoclonal antibody (mAb), but not by the addition of monosaccharide (N-acetylglucosamine, GlcNAc, a sugar specifically recognized by PWM and a lectin-like receptor on monocytes). In contrast, GlcNAc inhibited the DNA fragmentation in Raji cells induced by LDMC which the anti-TNFα mAb had no effect. PWM was found to stimulate the production of nitric oxide (NO) from monocytes. The NO-production was enhanced in the presence of target Raji cells, while the enhancement was abolished by the treatment with GlcNAc. By flow cytometry, we found that PWM bound to tumour cells as well as monocytes, and inhibited the expression of HLA-DR antigen on tumour cells. These results suggest that the presence of lectin molecules on the surface of monocytes and tumour cells may bring the two cells together, thus facilitating the induction of apoptosis in target cells by triggering the production of cytolytic factors (TNF and NO) and the modification of target cell surface antigen (HLA-DR).
AB - In this study we investigated the mechanisms of cytotoxicity mediated by pokeweed mitogen (PWM)-activated human peripheral blood monocytes. By using DNA electrophoresis and propidium iodide (PI)-DNA staining flow cytometry, we demonstrated that apoptotic cell death of target U937 cells and Raji cells was induced in lectin (PWM)-dependent monocyte-mediated cytotoxicity (LDMC). The LDMC-mediated DNA fragmentation in U937 cells and Raji cells was induced in lectin (PWM)-dependent monocyte mediated cytotoxicity(LDMC). The LDMC- mediated DNA fragmentation in U937 cells was completely inhibited by anti- TNFα monoclonal antibody (mAb), but not by the addition of monosaccharide (N-acetylglucosamine, GlcNAc, a sugar specifically recognized by PWM and a lectin-like receptor on monocytes). In contrast, GlcNAc inhibited the DNA fragmentation in Raji cells induced by LDMC which the anti-TNFα mAb had no effect. PWM was found to stimulate the production of nitric oxide (NO) from monocytes. The NO-production was enhanced in the presence of target Raji cells, while the enhancement was abolished by the treatment with GlcNAc. By flow cytometry, we found that PWM bound to tumour cells as well as monocytes, and inhibited the expression of HLA-DR antigen on tumour cells. These results suggest that the presence of lectin molecules on the surface of monocytes and tumour cells may bring the two cells together, thus facilitating the induction of apoptosis in target cells by triggering the production of cytolytic factors (TNF and NO) and the modification of target cell surface antigen (HLA-DR).
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U2 - 10.3109/08820139609059291
DO - 10.3109/08820139609059291
M3 - Article
C2 - 8675235
AN - SCOPUS:0029937740
SN - 0882-0139
VL - 25
SP - 65
EP - 78
JO - Immunological Investigations
JF - Immunological Investigations
IS - 1-2
ER -