Recombinant interleukin 2 allows the differentiation of Thy 1.2 + LAK cells from nude mouse spleen cells

Abstract

Culture of nude mouse spleen cells with recombinant human interleukin 2 (r-IL 2) resulted in the proliferation and generation of lymphokine-activated killer (LAK) cells which could lyse a variety of tumor cells. Flow cytometry study indicated that nude mouse spleen cells contained almost no Thy 1.2 + cells at the initial times of the culture, whereas LAK cells obtained from nude mouse spleen cells by culture with r-IL 2 (nude-LAK cells) expressed high intensity of Thy 1.2 antigen and lymphokine-activated cell-associated (LAA) antigen. The cytotoxic activity of nude-LAK cells was greatly reduced by treatment with anti-Thy 1.2 antibody plus complement but not with anti-Ly 1.2 or Ly 2.2 antibody plus complement treatment. Moreover, nude-LAK cells were resistant to the treatment with antiasialo GM1 antibody plus complement, in contrast to resident nude natural killer (NK) cells. These data strongly suggested that r-IL 2 allowed the nude mouse spleen cells to differentiate into Thy 1.2 +, Ly 1 −,2 −, asialo GM1 − LAK cells which were distinct from Thy 1.2 +, Ly 2 +, asialo GM1 − LAK cells induced from normal mouse spleen cells.