title: TNF-alpha potentiation of the lymphokine-activated killer response of murine thymus cells.
abstract: The role of tumor necrosis factor (TNF-alpha) on in vitro generation of lymphokine-activated killer (LAK) cells from murine thymocytes was investigated and compared to that on generation of LAK from splenocytes. TNF-alpha increased the potential of interleukin-2 (IL-2) at suboptimal concentrations to generate LAK activity in thymocytes even more than in splenocytes. In parallel, augmented [3H]thymidine uptake by thymocytes and splenocytes was seen. However, no net increase in viable cell number was observed. LAK effector cells from TNF-alpha plus IL-2 cultures responded with an increased [3H]thymidine uptake to restimulation by IL-2 alone. These results suggest that TNF-alpha + IL-2 may be inducing the expansion of a small subset of cells. NK1.1+ cells are a very minor subset of thymocytes, nevertheless phenotype analysis showed that in thymocytes, IL-2 + TNF-alpha generates NK1.1+ CD8- LAK effectors in contrast to NK1.1- CD8+ cells found with IL-2 alone. This result is consistent with the finding in the proliferation studies. The fact that thymocytes are stimulated by the TNF-alpha + IL-2 combination to proliferate as well as to develop a phenotypically distinct effector supports the role of TNF-alpha in intra- and extrathymic regulation.
authors.forename: P
authors.initials: P
authors.lastname: Ujházy
authors.forename: D
authors.initials: D
authors.lastname: Maccubbin
authors.forename: C
authors.initials: C
authors.lastname: Eppolito
authors.forename: E
authors.initials: E
authors.lastname: Mihich
authors.forename: M J
authors.initials: MJ
authors.lastname: Ehrke
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D003602:Cytotoxicity, Immunologic; D004357:Drug Synergism; D005260:Female; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000008:administration & dosage; D015979:Killer Cells, Lymphokine-Activated / Q000187:drug effects* / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010641:Phenotype; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology*; D014407:Tumor Cells, Cultured / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000943:Antigens, Differentiation; D007376:Interleukin-2; D014409:Tumor Necrosis Factor-alpha