BACKGROUND AND OBJECTIVES: B-cell chronic lymphocytic leukemia (B-CLL) is a clonal expansion of CD5+B cells that accumulate due to their uncontrolled growth and resistance to apoptosis. We have previously shown that up to 50% of blood CD4+ T cells in B-CLL patients have a cytotoxicity-related CD28- CD57+ phenotype and high content of both granzyme B and perforin (PF). In this study we investigate the cytotoxic potential of these cells against autologous B-CLL cells. DESIGN AND METHODS: Blood CD4+ or CD8+ T cells were positively isolated from B-CLL patients and cultured under a range of conditions with autologous purified B-CLL cells and with bispecific [anti-CD3 x anti-CD19] antibodies. Apoptosis of labeled B-CLL cells was assessed using the change of mitochondrial membrane potential with the fluorescent dye DiOC6 and confirmed by annexin V binding. RESULTS: There was time- and dose-dependent killing of B-CLL cells by both CD8+ and CD4+ T cells and this ranged from 6.6 - 68.0% for CD4+ cells and 6.4 - 57.8% for CD8+ cells. Almost complete inhibition by concanamycin A suggests that CD4+ T cells like CD8+ T cells induced apoptosis through a perforin-mediated pathway, but not via Fas/FasL (as indicated by lack of blocking with brefeldin A), tumor necrosis factor alpha or TRAIL. INTERPRETATION AND CONCLUSIONS: This study shows that blood CD4+PF+ T cells enriched in B-CLL patients, are able to kill autologous B-CLL cells ex vivo, through bispecific antibodies via a perforin mediated mechanism.
BACKGROUND AND OBJECTIVES: B-cell chronic lymphocytic leukemia (B-CLL) is a clonal expansion of CD5+B cells that accumulate due to their uncontrolled growth and resistance to apoptosis. We have previously shown that up to 50% of blood CD4+ T cells in B-CLL patients have a cytotoxicity-related CD28- CD57+ phenotype and high content of both granzyme B and perforin (PF). In this study we investigate the cytotoxic potential of these cells against autologous B-CLL cells. DESIGN AND METHODS: Blood CD4+ or CD8+ T cells were positively isolated from B-CLL patients and cultured under a range of conditions with autologous purified B-CLL cells and with bispecific [anti-CD3 x anti-CD19] antibodies. Apoptosis of labeled B-CLL cells was assessed using the change of mitochondrial membrane potential with the fluorescent dye DiOC6 and confirmed by annexin V binding. RESULTS: There was time- and dose-dependent killing of B-CLL cells by both CD8+ and CD4+ T cells and this ranged from 6.6 - 68.0% for CD4+ cells and 6.4 - 57.8% for CD8+ cells. Almost complete inhibition by concanamycin A suggests that CD4+ T cells like CD8+ T cells induced apoptosis through a perforin-mediated pathway, but not via Fas/FasL (as indicated by lack of blocking with brefeldin A), tumor necrosis factor alpha or TRAIL. INTERPRETATION AND CONCLUSIONS: This study shows that blood CD4+PF+ T cells enriched in B-CLL patients, are able to kill autologous B-CLL cells ex vivo, through bispecific antibodies via a perforin mediated mechanism.
Authors: Ganesh Rao; Khatri Latha; Martina Ott; Aria Sabbagh; Anantha Marisetty; Xiaoyang Ling; Daniel Zamler; Tiffany A Doucette; Yuhui Yang; Ling-Yuan Kong; Jun Wei; Gregory N Fuller; Fernando Benavides; Adam M Sonabend; James Long; Shulin Li; Michael Curran; Amy B Heimberger Journal: Clin Cancer Res Date: 2020-06-18 Impact factor: 12.531
Authors: Camilla A Lindqvist; Lisa H Christiansson; Ingrid Thörn; Sara Mangsbo; Gabriella Paul-Wetterberg; Christer Sundström; Thomas H Tötterman; Bengt Simonsson; Gunilla Enblad; Per Frisk; Ulla Olsson-Strömberg; Angelica S I Loskog Journal: Immunology Date: 2011-04-05 Impact factor: 7.397
Authors: Jiusheng Deng; Andrea Pennati; Jonathon B Cohen; Yuanqiang Wu; Spencer Ng; Jian Hui Wu; Christopher R Flowers; Jacques Galipeau Journal: J Transl Med Date: 2016-04-27 Impact factor: 5.531