Enhancement of granulocyte luminescence by murine macrophage secretory products: Suggestive evidence for the release of a new activator
✍ Scribed by Willems, J. ;Leclercq, G. ;Joniau, M.
- Publisher
- John Wiley and Sons
- Year
- 1990
- Weight
- 413 KB
- Volume
- 5
- Category
- Article
- ISSN
- 0884-3996
No coin nor oath required. For personal study only.
✦ Synopsis
The incubation of macropages (M@) in the presence of lipopolysaccharides (LPS) usually results in the release of a variety of immunoregulatory cytokines such as interleukins (ILL tumour necrosis factor (TNF) and colony stimulating factors (CSF). We recently observed that conditioned media (CM) from LPS-treated murine M$ lines probably contain another protein endowed with granulocyte stimulatory activity. This cytokine, which has an apparent M W of about 55 kDa enhances the PMA-induced luminescence of granulocytes and also stimulates their degranulation as measured by lactoferrin release. In contrast t o IL, and IL6 this factor is destroyed by brief treatment at pH 2, but is stable for 60 minutes at 65°C. Unlike CSF, its activity is unchanged by reducing agents such as beta-mercaptoethanol. Furthermore, pretreatment of the M@ with dexamethasone, in order t o reduce the release of IL, and TNF, hardly reduces the effect on granulocyte activation. Finally, treatment with a neutralizing polyclonal anti-murine TNF antiserum only partly abolishes its activity.
These results show that, in addition t o the already well-described cytokines, LPS-treated murine M@ lines most probably secrete another granulocyte activator.