Abstract
The cytokine IL-12 promotes Th(1)type immune responses and plays a key role in immune regulation. The complex nature of IL-12 hampered its detection without use of stimulants that might give less relevant information. To detect circulating IL-12 p40, we developed enzyme-linked immunospot (ELISPOT) assays that allow enumeration of IL-12 p40 secreting cells without prior in vitro stimulation of the cells. In parallel, intracellular staining of IL-12 p40 by flow cytometry was performed to compare the two methods. IL-12 p40 secreting cells were detected in healthy subjects at a mean number of 103+/-155 per 10(5)blood mononuclear cells (MNC). Numbers of IL-12 p40 secreting blood MNC correlated with IL-12 p40 positive blood MNC detected by flow cytometry. Bacterial endotoxins and the inflammatory cytokines TNF-alpha and IFN-gamma control IL-12 production by antigen presenting cells. Utilizing IL-12 p40 ELISPOT assays, we could confirm occurrence of elevated numbers of IL-12 p40 secreting blood MNC after stimulation with TNF-alpha, IFN-gamma, LPS, LPS+TNF-alpha or LPS+IFN-gamma, compared to cultures without stimulant. Due to its central role in inflammation and autoimmunity, IL-12 is an attractive target for immunotherapy. IL-12 p40 ELISPOT assays represent a sensitive, specific and reliable tool for investigating the role of IL-12 in both health and disease.
Original language | English |
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Pages (from-to) | 1218-24 |
Number of pages | 7 |
Journal | Cytokine Plus |
Volume | 12 |
Issue number | 8 |
DOIs | |
Publication status | Published - Aug 2000 |
Keywords
- Adult
- Aged
- Enzyme-Linked Immunosorbent Assay/methods
- Evaluation Studies as Topic
- Female
- Flow Cytometry/methods
- Humans
- Interferon-gamma/metabolism
- Interleukin-12/analysis
- Kinetics
- Leukocytes, Mononuclear/metabolism
- Lipopolysaccharides/pharmacology
- Male
- Middle Aged
- Tumor Necrosis Factor-alpha/metabolism