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Updated: Jun 21, 2026
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Analyzing the Functions of Mast Cells In Vivo Using 'Mast Cell Knock-in' Mice
Published on: May 27, 2015
Intracellular IL-15 controls mast cell survival
Farhad Mirghomizadeh1, Supandi Winoto-Morbach, Zane Orinska
1Department of Immunology and Cell Biology, Research Center Borstel, Parkallee 22, D-23845 Borstel, Germany.
Experimental Cell Research
|July 28, 2009
Summary
Interleukin-15 (IL-15) regulates mast cell survival and homeostasis. IL-15 deficiency in mice leads to increased mast cell apoptosis, suggesting IL-15 is crucial for maintaining mast cell populations.
Area of Science:
- Immunology
- Cell Biology
- Molecular Biology
Background:
- Mast cell survival and activity are critical for immune responses.
- Interleukin-15 (IL-15) is a pro-inflammatory cytokine with diverse roles in immunity.
- Understanding IL-15's function in mast cell homeostasis is essential for inflammatory disease research.
Purpose of the Study:
- To investigate the role of mouse interleukin-15 (IL-15) in regulating mast cell survival and homeostasis.
- To determine the impact of IL-15 deficiency on mast cell apoptosis and related molecular pathways.
Main Methods:
- Comparison of mast cell numbers in aged IL-15 knockout (IL-15-/-) mice and wild-type (WT) mice.
- Assessment of apoptosis in bone marrow-derived mouse mast cells (BMMCs) from IL-15-/- and WT mice under various conditions.
- Analysis of mRNA, protein expression, and enzymatic activity of apoptotic pathway components (e.g., Cathepsin D, acid sphingomyelinase, caspases) in BMMCs.
- Measurement of ceramide and sphingosine-1-phosphate levels in BMMCs.
- Evaluation of mast cell survival upon treatment with pathway inhibitors (imipramine, pepstatin A).
Main Results:
- Aged IL-15-/- mice exhibited fewer peritoneal mast cells than WT mice.
- IL-15 deficient BMMCs showed increased susceptibility to apoptosis induced by growth factor deprivation and acid sphingomyelinase (A-SMase) treatment.
- IL-15-/- BMMCs displayed elevated expression and activity of key apoptotic factors, including Cathepsin D (CTSD), A-SMase, caspase-3, and caspase-7.
- IL-15-/- BMMCs produced higher levels of A-SMase-derived ceramide and lower levels of pro-survival sphingosine-1-phosphate (SPP).
- Inhibition of A-SMase or CTSD pathways enhanced survival of IL-15-/- BMMCs.
Conclusions:
- Intracellular IL-15 is a key regulator of primary mouse mast cell homeostasis.
- IL-15 deficiency disrupts the balance of pro- and anti-apoptotic pathways in mast cells, particularly involving ceramide and sphingosine-1-phosphate metabolism.
- Targeting IL-15-regulated pathways may offer therapeutic strategies for inflammatory conditions involving mast cells.
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