Efficient elimination of chronic lymphocytic leukaemia B cells by autologous T cells with a bispecific anti-CD19/anti-CD3 single-chain antibody construct.
Recently, we have shown that a novel recombinant bispecific single-chain antibody construct (bscCD19 x CD3), induces highly efficacious lymphoma-directed cytotoxicity mediated by unstimulated peripheral T lymphocytes. Functional analysis of bscCD19 x CD3 has so far been exclusively performed with human B lymphoma cell lines and T cells from healthy donors. Here we analysed the properties of bscCD19 x CD3 using primary B cells and autologous T cells from healthy volunteers or patients with B-cell chronic lymphocytic leukaemia (B-CLL). We show that bscCD19 x CD3 induces T-cell-mediated depletion of nonmalignant B cells in all four cases and depletion of primary lymphoma cells in 22 out of 25 cases. This effect could be observed at low effector-to-target (E:T) ratios and in the majority of cases without additional activation of autologous T cells by IL-2. Even in samples derived from patients heavily pretreated with different chemotherapy regimens, strong cytotoxic effects of bscCD19 x CD3 could be observed. The addition of bscCD19 x CD3 to patients' cells resulted in an upregulation of activation-specific cell surface antigens on autologous T cells and elevated levels of CD95 on lymphoma B cells. Although anti-CD95 antibody CH-11 failed to induce apoptosis in lymphoma cells, we provide evidence that B-CLL cell depletion by bscCD3 x CD3 is mediated at least in part by apoptosis via the caspase pathway.
Löffler
A
A
Department of Haematology, Oncology and Tumourimmunology, Robert Rössle Clinic, Charité, Humboldt University of Berlin, Berlin, Germany.
Gruen
M
M
Wuchter
C
C
Schriever
F
F
Kufer
P
P
Dreier
T
T
Hanakam
F
F
Baeuerle
P A
PA
Bommert
K
K
Karawajew
L
L
Dörken
B
B
Bargou
R C
RC
D000368:Aged; D000369:Aged, 80 and over; D017304:Annexin A5 / Q000378:metabolism; D018033:Antibodies, Bispecific / Q000627:therapeutic use*; D000918:Antibody Specificity; D018941:Antigens, CD19 / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology*; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D003602:Cytotoxicity, Immunologic; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D007376:Interleukin-2 / Q000378:metabolism; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000276:immunology / Q000628:therapy*; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008212:Lymphocyte Depletion; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology*; D014407:Tumor Cells, Cultured
D017304:Annexin A5; D018033:Antibodies, Bispecific; D018941:Antigens, CD19; D017252:CD3 Complex; D061945:Caspase Inhibitors; D007376:Interleukin-2; D020169:Caspases