title: Killing of human leukaemia/lymphoma B cells by activated cytotoxic T lymphocytes in the presence of a bispecific monoclonal antibody (alpha CD3/alpha CD19).
abstract: Bispecific antibodies (BsAb) can be used to retarget T cells irrespective of their specificity to certain target cells inducing target cell lysis. We have tested the efficacy of the BsAb SHR-1, directed against the T cell antigen CD3 and the B cell antigen CD19 to induce (malignant) B cell kill by T cells as measured in a 51Cr-release assay. Two cytotoxic T cell clones (CTL), expressing TCR alpha beta or TCR gamma delta, were effective in killing CD19 expressing B cell lines at different stages of differentiation in the presence, but not in the absence, of the BsAb. CD19- target cells were not killed. Fresh CD19+ leukaemia/lymphoma cells were also efficiently killed by SHR-1 preincubated CTL clones. In addition, phytohaemagglutinin (PHA) or CD3-activated IL-2 expanded peripheral blood mononuclear cells (PBMC) of normal donors did so after 2 weeks of stimulation. A concentration of 100 ng/ml of the BsAb was sufficient to obtain optimal lysis of all target cells tested. These results show that fresh human leukaemia/lymphoma cells, freshly derived from active lymphoblastic leukaemia (ALL) as well as non-Hodgkin's lymphoma (NHL) patients, can be effectively killed in the presence of this BsAb by activated T cells.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D000920:Antibody-Dependent Cell Cytotoxicity; D015703:Antigens, CD / Q000276:immunology*; D018941:Antigens, CD19; D000944:Antigens, Differentiation, B-Lymphocyte / Q000276:immunology*; D017252:CD3 Complex / Q000276:immunology*; D002459:Cell Fusion; D002999:Clone Cells; D006801:Humans; D006822:Hybrid Cells; D007376:Interleukin-2 / Q000494:pharmacology; D015448:Leukemia, B-Cell / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D016393:Lymphoma, B-Cell / Q000276:immunology*; D051381:Rats; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018941:Antigens, CD19; D000944:Antigens, Differentiation, B-Lymphocyte; D017252:CD3 Complex; D007376:Interleukin-2