Activation of tumor necrosis factor-alpha production from human neutrophils by IL-2 via IL-2-R beta.
In addition to T cells, NK cells, B cells, and monocytes, we provide new evidence that human polymorphonuclear neutrophils (PMN) can be functionally activated by IL-2 via binding to IL-2R beta expressed on the cell surface. Brief exposure of normal PMN to human rIL-2 enhanced both transcriptional and translational expression of TNF-alpha. The release of TNF-alpha protein by IL-2-treated PMN was inhibitable by a specific mAb against human IL-2-R beta. The response to IL-2 was dose and time dependent with the increase in TNF-alpha mRNA detected maximally 3 h after IL-2 exposure, followed by a continuous maintenance of high mRNA levels up to 18 h. The TNF-alpha mRNA was significantly increased above the medium control level, with as little as 10 U/ml of IL-2. Maximal transcription was obtained with 1000 U/ml of IL-2, which achieved the level observed with known neutrophil activating factors such as granulocyte-macrophage-CSF, IL-8, and Candida albicans. Using actinomycin D, it was found that new and continuous synthesis of a labile TNF-alpha mRNA was responsible for the observed high levels of transcripts. Of significance was the observation that cycloheximide could selectively modulate TNF-alpha mRNA transcription in neutrophils, depending on the cytokine used. Cycloheximide did not affect or alter TNF-alpha mRNA induction in IL-2-treated neutrophils but abrogated it in granulocyte-macrophage-CSF-treated neutrophils and superinduced transcription in C. albicans-treated neutrophils. Thus various control elements must be involved in the transcription of the TNF-alpha genes that are responsive to different cytokines and activating factors. The induction of TNF-alpha and functional activation of neutrophils by IL-2 is therefore an important immunomodulatory property of IL-2 that has not heretofore been recognized.
Wei
S
S
H. Lee Moffitt Cancer Center, University of South Florida College of Medicine, Department of Medical Microbiology and Immunology, Tampa 33612.
Blanchard
D K
DK
Liu
J H
JH
Leonard
W J
WJ
Djeu
J Y
JY
D000911:Antibodies, Monoclonal / Q000276:immunology; D002176:Candida albicans / Q000276:immunology; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D016209:Interleukin-8 / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D015375:Receptors, Interleukin-2 / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics
D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D016209:Interleukin-8; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D014409:Tumor Necrosis Factor-alpha; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D003513:Cycloheximide