Related Experiment Videos
Production of interleukin-1-alpha and -beta by human peripheral polymorphonuclear neutrophils
1Department of Dermatology, Teikyo University School of Medicine, Tokyo, Japan.
Abstract:
The mechanism of the production of interleukin-1 (IL-1) by human peripheral polymorphonuclear neutrophils (PMN) was investigated. Supernatants of PMN stimulated with 30 micrograms/ml lipopolysaccharide (LPS) were used as extracellular IL-1 and supernatants of their lysate as intracellular IL-1 source. IL-1 activity was measured by the C3H/HeJ thymocyte co-mitogenic assay. The supernatants from PMN stimulated with LPS for 72 h showed IL-1 activity which had an apparent molecular weight of 15-20 kilodaltons and pI of 5.0 and more than 8.5. It was neutralized with anti-IL-1 antibodies and it lacked IL-2 activity. Our time course study of the IL-1 assay with neutralization by anti-IL-1-alpha and -beta antibodies indicated that the extracellular IL-1-beta activity appeared predominantly in the early incubation periods, whereas alpha activity appeared predominantly in the late periods. Intracellular IL-1-alpha but not beta activity was detected mainly at the intermediate incubation periods. These data indicate that PMN stimulated with LPS produce both IL-1-alpha and -beta, and release IL-1-beta first and IL-1-alpha later.
Insights
Human neutrophils stimulated with lipopolysaccharide (LPS) produce both interleukin-1 alpha and beta (IL-1α/β). Extracellular IL-1β is released early, while IL-1α is released later, with intracellular IL-1α detected during intermediate periods.
Area of Science:
- Immunology
- Cell Biology
Background:
- Interleukin-1 (IL-1) is a key cytokine in immune responses.
- Polymorphonuclear neutrophils (PMN) are crucial immune cells involved in inflammation.
- Understanding IL-1 production mechanisms by PMN is vital for inflammatory disease research.
Purpose of the Study:
- To investigate the mechanism of interleukin-1 (IL-1) production by human peripheral polymorphonuclear neutrophils (PMN).
- To characterize the temporal release and localization of IL-1 alpha and IL-1 beta isoforms.
Main Methods:
- PMN were stimulated with lipopolysaccharide (LPS).
- Extracellular IL-1 was obtained from supernatants, and intracellular IL-1 from lysate.
- IL-1 activity was quantified using the C3H/HeJ thymocyte co-mitogenic assay.
- IL-1 isoforms were characterized by molecular weight, pI, and neutralization with specific antibodies.
Main Results:
- LPS-stimulated PMN produced IL-1 with molecular weight of 15-20 kDa and pI values of 5.0 and >8.5.
- The produced IL-1 activity was neutralized by anti-IL-1 antibodies and lacked IL-2 activity.
- Extracellular IL-1 beta was predominantly detected in early incubation periods, while IL-1 alpha appeared later.
- Intracellular IL-1 alpha was mainly detected during intermediate incubation periods, whereas IL-1 beta was not detected intracellularly.
Conclusions:
- Human PMN stimulated with LPS produce both IL-1 alpha and IL-1 beta.
- PMN release IL-1 beta extracellularly before releasing IL-1 alpha.
- These findings elucidate the distinct temporal dynamics of IL-1 isoform production and release by neutrophils.