Effect of actinomycin D on cytotoxic activity of immune lymphocytes in tissue culture

Lymphocyte Receptors and Mechanisms of in Vitro Cell‐Mediated Immune Reactions

“…This result docs not depend upon the arrangement of the test; it has been obtained with the same lymphocytes and targets of different genotypes or, conversely, with lymphocytes of different specificities and target cells of one genotype (Table II). In contrast to immune lymphocytes, humoral alloantibodies react with target cells (in tests of dextran hemagglutination and cytotoxicity in vitro) irrespective of the ratio of reacting to immunizing antigens (Brondz 1968).…”

“…(5) Rabbit anti-mouse yG-, j-M-and ;'A-globulin do not inhibit in vitro CE of immune lymphocytes on allogeneic target cells (Brondz et al 1968, IN VrTRO CYTOTOXICITY 131 Mauel et al 1970)*, or transfer of DH or graft-versus-host reaction by the cells (Ivanyi et al 1970, Mason & Warner 1970)**. On the contrary, cytotoxic allo-anti bodies (Brondz et al 1968) and CE of immune lymphocytes on xenogeneic target cells (guinea pig versus mouse) are neutralized by anti-Ig.…”

“…If the antigen is present in the membrane of living target cells, interaction of lymphocytes with the antigen is more complicated and requires more time -from 1 to 6 hours (Wilson 1965, Brunner et al 1968, Brondz 1968, Canty et al 1970. However, in this case also lymphocytes come into direct contact with the appropriate antigen: their effect on target cells is strictly specific , Brondz 1968) and fails when lymphocytes are separated from target cells by a membrane filter (Wilson 1965a, Rosenau 1968.…”

“…If the antigen is present in the membrane of living target cells, interaction of lymphocytes with the antigen is more complicated and requires more time -from 1 to 6 hours (Wilson 1965, Brunner et al 1968, Brondz 1968, Canty et al 1970. However, in this case also lymphocytes come into direct contact with the appropriate antigen: their effect on target cells is strictly specific , Brondz 1968) and fails when lymphocytes are separated from target cells by a membrane filter (Wilson 1965a, Rosenau 1968. For quantitative assay of specific absorption of the immunologically active fraction of lymphocytes, the latter were incubated with target cells of different genotypes for varying periods of time (1, 3, 4 or 6 hours); nonadhering lymphocytes were harvested and their cytotoxic activity was tested in parallel on the appropriate target cells.…”

Lymphocyte in vitro cytotoxicity: Mechanism of human lymphotoxin-induced target cell destruction

“…The relationship of these systems to one another and the mechanism of how cell destruction occurs is still not known. However, in most instances it appears that lymphoid-target cell contact per se is not sufficient to cause the cellular destruction (12,(19)(20)(21), but an active lymphocyte process independent of DNA synthesis (22)(23)(24) involving energy metabolism and perhaps protein biosynthesis is required (21,(25)(26)(27). There is no satisfactory explanation as yet for the actual mechanism of how destruction occurs.…”