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Fas (CD95, APO-1) antigen expression and function in murine mast cells
K Hartmann1, A L Wagelie-Steffen, E von Stebut
1Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA.
Journal of Immunology (Baltimore, Md. : 1950)
|October 23, 1997
Summary
Mast cells can undergo apoptosis via the Fas pathway, a mechanism that helps regulate their numbers. This study investigated Fas Ag expression and apoptosis induction in mast cells.
Area of Science:
- Immunology
- Cell Biology
Background:
- Mast cells are crucial immune cells involved in allergic responses and inflammation.
- Mast cell numbers are regulated by apoptosis, a process of programmed cell death.
- Growth factor deprivation is known to induce mast cell apoptosis.
Purpose of the Study:
- To investigate if mast cells undergo apoptosis upon activation through the Fas pathway (also known as CD95 or APO-1).
- To explore the role of Fas-mediated apoptosis in regulating mast cell populations.
Main Methods:
- Flow cytometry was used to assess surface expression of Fas Ag.
- Apoptosis was analyzed using propidium iodide (PI) uptake, TUNEL staining, DNA electrophoresis, and electron microscopy.
- Experiments involved murine bone marrow-cultured mast cells (BMCMC), peritoneal mast cells, and mast cell lines (C57, MCP-5).
Main Results:
- Mast cell lines and primary mast cells constitutively expressed Fas Ag.
- Anti-Fas antibody-induced apoptosis was observed in C57 mast cells.
- BMCMC were resistant to anti-Fas antibody alone but underwent apoptosis when combined with actinomycin D.
- Stem cell factor, TGF-beta, and Fc epsilon RI aggregation influenced Fas expression, with SCF and TGF-beta offering partial protection against Fas-mediated apoptosis.
Conclusions:
- Activation of the Fas pathway is an additional mechanism for inducing mast cell apoptosis.
- This Fas-mediated apoptosis pathway contributes to the regulation of mast cell numbers in biological systems.