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Functional Characterization of Lymphokines From the EL‐4 T Cell Line That Activate Macrophages for Nonspecific Tumor Cytotoxicity
Author(s) -
Occhionero Massimo,
Leonard Edward J.,
Meltzer Monte S.
Publication year - 1984
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.35.4.405
Subject(s) - cytotoxic t cell , lymphokine , biology , cell culture , cytotoxicity , spleen , priming (agriculture) , microbiology and biotechnology , macrophage , in vitro , immunology , antigen , biochemistry , genetics , germination , botany
Culture fluids from a phorbol myristate acetate‐stimulated EL‐4 thymoma cell line were previously found to activate mouse macrophages to become nonspecifically tumoricidal. By gel filtration, 23,000‐ and 45,000‐MW peaks were identified. In this study we compared EL‐4 culture fluid activity with that obtained from antigen‐stimulated mouse spleen cells. By four criteria, functional activity from the two sources was comparable: 1) Macrophage activation could be separated temporally into two steps, priming and triggering. 2) Macrophages activated by the fluids exhibited peak cytotoxic activity within 5–9 hr; no cytotoxic activity was demonstrable if addition of target cells was delayed 14 hr. 3) Mouse peritoneal exudate macrophages, but not resident macrophages, became cytotoxic after a 5‐hr incubation with culture fluids. 4) Macrophages from certain strains of mice were incapable of activation; the same pattern of strain unresponsiveness was observed with both EL‐4 and spleen cell culture fluids. Thus, it is likely that the two EL‐4 products and the mouse spleen cell lymphokine activate the same cytotoxic mechanism.