QUANTITATIVE ASSAY OF LYTIC ACTION OF IMMUNE LYMPHOID CELLS ON 51CR-LABELLED ALLOGENEIC TARGET CELLS IN VITRO - INHIBITION BY ISOANTIBODY AND BY DRUGS

  • 1 January 1968
    • journal article
    • research article
    • Vol. 14  (2) , 181-+
Abstract
The in vitro cytotoxic effect of spleen cells of mice immunized by tumor allografts was studied by measuring target cell inactivation as a func -tion of release of radioactive label (51Cr) or loss of cloning efficiency. When sensitized lymphoid cells were incubated with target cells at a ratio of 100:1, up to 90% of the incorporated label was released within 6-9 hr, while the number of clone-forming cells was reduced by up to 99% in the same time period. Isoantiserum from the graft recipients, as well as its 19S and 7S fractions, protected target cells against the toxic effect of the spleen cells, but a lipoprotein antigen isolated from the tumor cells failed to inhibit the cytotoxic reaction. Target cell lysis as measured by specific release of 51Cr was partially inhibited by actinomycin-D and by cycloheximide at concentrations which effectively blocked DNA-dependent RNA and protein synthesis.