Abstract
This study examined the secretion of IL-1α and IL-1ß by THP-1 leukemia cells following activation with mezerein and promotion of synthesis by interferon (IFN-γ). Interleukin-1 (IL-1) was not detected by co-mitogenic thymocyte assays of crude supernates. Isoelectrofocusing of concentrated medium showed that all biologically active IL-1 migrated at a pH of 6.8-7.2, indicating that the major secreted form was IL-1β. Double antibody ELISA confirmed the presence of IL-1β, but failed to detect IL-1α in isofocused fractions. Although it appeared that THP-1 cells do not secrete IL-1α; an inhibitor of thymocyte response to IL-1 was present in conditioned medium, migrated in an acidic pH range and masked the expression of biologically active rIL-1α and rIL-1ß. In contrast, IL-1α was detected using a cell blotting assay. This technique permitted visualization of subpicogram levels of IL-1 when secreted by cells attached to an immunoblotting paper. Cell blotting showed that a greater proportion of attached cells incubated for 24 h in medium containing mezerein and IFN-γ secreted IL-1 than cells in control medium. In conclusion, the amount of immunoreactive or biologically active IL-1α secreted by stimulated THP-1 cells appeared to be much lower than that reported for human peripheral blood monocytes.
Original language | English (US) |
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Pages (from-to) | 211-218 |
Number of pages | 8 |
Journal | Journal of Immunological Methods |
Volume | 122 |
Issue number | 2 |
DOIs | |
State | Published - Sep 1 1989 |
Externally published | Yes |
Keywords
- Cell blot
- ELISA
- Interleukin-1
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology