Platelets contain interleukin-1 alpha and beta which are detectable on the cell surface after activation
P Sedlmayr1, A Blaschitz, M Wilders-Truschnig
1Department of Internal Medicine, Karl-Franzens-University, Graz, Austria.
Scandinavian Journal of Immunology
|August 1, 1995
Summary
Interleukin-1 (IL-1) alpha and beta are found in platelet cytoplasm. Following activation, IL-1 is present on the surface, but mainly released upon platelet disintegration.
Area of Science:
- Hematology
- Immunology
- Cell Biology
Background:
- Activated platelets display Interleukin-1 (IL-1) bioactivity.
- The precise localization of IL-1 within platelets remains unclear.
Purpose of the Study:
- To investigate the intracellular and cell surface localization of IL-1 alpha and IL-1 beta in resting and activated platelets.
Main Methods:
- Immunocytological techniques
- Flow cytometry
- Immunogold-silver staining
- Pre-embedding antibody treatment
Main Results:
- IL-1 alpha and IL-1 beta were detected in the cytoplasm of both resting and activated platelets.
- Low-density IL-1 was found on the surface of intact activated platelets, with higher enrichment in damaged platelets.
- Evidence suggests IL-1 adsorption to fibrin fibers and weak binding to activated platelet surfaces.
Conclusions:
- Both IL-1 alpha and IL-1 beta are present in resting and activated platelets.
- IL-1 appears to transfer to the activated platelet surface, but significant release likely occurs only after platelet disintegration.
- Specific subcellular localization of IL-1 within platelets could not be demonstrated.
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