Biological features of human T-activated killer cells

Abstract

Objective: To investigate the immunobiological essence of T-activated killer (T-AK) cells induced by anti-CD 3 monoclonal antibody (CD 3 McAb) and recombinant interleukin-2 (rIL-2) co-stimulation. Methods: The cytomorphology, phenotype and cytotoxicity of T-AK cells generated from human peripheral blood mononuclear cells (PBMC) were determined. Results: T-AK cells were similar to activated lymphoblasts in morphology, more than 90% of T-AK cells expressed the phenotypes of Tlymphocytes (CD 3 + , CD 8 + ), and 20%-50% of the cells were NK-like phenotype (CD 16 + , CD 56 + ), some of them expressed IL-2 receptor (CD 25 + ), CD 38 antigen (CD 38 + ) and MHC-II antigen (HLA-DR + ) characteristic marks for the activated T lymphocytes. T-AK cells attacking targets were morphologically large volumes with granules and mainly contained CD 8 + and CD 56 + cells. TAK cells possessed high tumoricidal activities against NK-sensitive Ks62 cells and NK-resistant Raji cells, the cytotoxicity was composed of mainly CDaMcAbactivated CD3AK activity (-50%), IL-2 induced LAK activity (-30%), NK activity (-10%) and the activities of inhibitory factors in T-AK supernatant (-10%). Conclusion: T-AK cells are a heterogeneous cell population consisting of mainly activated T lymphocytes and NK-like cells, the main part of T-AK cytotoxicity is the common activities of CD3AK cells and LAK cells.