Ultrastructural and functional studies of the interaction between IL-12 and IL-2 for the generation of lymphokine-activated killer cells.
IL-12 promotes generation of LAK activity in short-term-cultured NK cells, but information on the structure and function of IL-12-induced LAK cells is not yet available. The latter issues have been here investigated with emphasis on interactions between IL-12 and IL-2. Peripheral blood mononuclear cells (MNC) exposed to IL-12 for 5-7 days displayed a decrease in the amount and density of the matrix of large granular lymphocyte (LGL)-associated granules. In cells cultured with IL-12 and IL-2 for 5-7 days, empty vacuoles were predominant and the electron-dense matrix was scanty. In MNC incubated with IL-2 for 5-7 days, most granules were loaded with electron-dense matrix. IL-12 and IL-2 displayed an additive effect on LAK cell cytotoxicity until approximately 48 h in culture which was followed by a sharp decline. Immunocytochemical and biochemical studies demonstrated that MNC cultured for 5-7 days with IL-12 and IL-2 displayed downregulated perforin expression and upregulated granzyme B expression. Fas ligand expression was virtually undetectable in MNC cultured for 5-7 days with or without cytokines. It appears that perforin downregulation plays a major role in the reduced cytotoxicity of MNC cultured with IL-12 and IL-2 for 5-7 days.
Facchetti
P
P
Laboratory of Oncology, G. Gaslini Institute, Largo G. Gaslini, 5, Genova, 16148, Italy.
Tacchetti
C
C
Prigione
I
I
Airoldi
I
I
Favre
A
A
Grossi
C E
CE
Pistoia
V
V
D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D003594:Cytoplasmic Granules / Q000276:immunology / Q000648:ultrastructure; D053222:Fas Ligand Protein; D053804:Granzymes; D006801:Humans; D018664:Interleukin-12 / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology; D007376:Interleukin-2 / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000201:enzymology* / Q000276:immunology* / Q000648:ultrastructure; D007700:Kinetics; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000378:metabolism; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D012697:Serine Endopeptidases / Q000096:biosynthesis / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism
C505661:FASLG protein, human; D053222:Fas Ligand Protein; D007376:Interleukin-2; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D019014:fas Receptor; D054353:Perforin; D018664:Interleukin-12; C509213:GZMB protein, human; D053804:Granzymes; D012697:Serine Endopeptidases