Long-term cultures of mouse bone marrow cells: a model for studying the generation of natural killer cells.
We investigated the generation of natural killer (NK) cells, using a long-term bone marrow culture (LTBMC) system. Mouse bone marrow cells were cultured for 2 weeks in complete medium without growth factors to obtain an enriched population of NK precursor cells. When these cells were recultured in the presence of interleukin-2 (IL-2) and conditioned medium (CM) from LTBMC, lytic NK cells were generated within 4 days. Replacing CM with fresh medium, before adding IL-2, decreased NK cell generation markedly, suggesting that endogenous factors present in CM were necessary for IL-2 induction of NK cells. NK cell precursors were also cultured with a combination of IL-2 and interferon-gamma (IFN-gamma) or IL-2 and tumor necrosis factor-alpha (TNF-alpha), but no CM. Results show that IFN-gamma and TNF-alpha were able to substitute CM. The addition of anti-IFN-gamma or anti-TNF-alpha antibodies to LTBMC cells, cultured in the presence of IL-2 and CM, inhibited cytotoxicity induction in a dose-dependent manner. The data indicate that IFN-gamma and TNF-alpha production may be required for IL-2 induction of NK activity, and are consistent with the hypothesis that NK generation involves collaboration between IL-2 and other bone marrow microenvironmental growth factors.
Ayroldi
E
E
Institute of Pharmacology, School of Medicine, University of Perugia, Italy.
Cannarile
L
L
D'Adamio
F
F
Delfino
D
D
Migliorati
G
G
Riccardi
C
C
D000818:Animals; D000911:Antibodies, Monoclonal; D001853:Bone Marrow / Q000276:immunology*; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D002478:Cells, Cultured; D003470:Culture Media; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000276:immunology; D007376:Interleukin-2 / Q000276:immunology; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology*; D008137:Longitudinal Studies; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D011994:Recombinant Proteins; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
D000911:Antibodies, Monoclonal; D003470:Culture Media; D007376:Interleukin-2; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma