New inducible mast cell-deficient mouse model (Mcpt5/Cma1^DTR)

Area of Science:

• Immunology
• Genetics

Background:

• Mast cells play vital roles in vivo, necessitating models for their study.
• Existing mouse models do not achieve specific depletion of all mast cell populations.

Purpose of the Study:

• To develop a novel mouse model for conditional depletion of all mast cell populations.
• To validate the efficacy of this model in eliminating mast cells across various tissues.

Main Methods:

• Generation of knock-in mice (Mcpt5/Cma1^DTR) expressing the diphtheria toxin receptor under the Mcpt5 promoter.
• Intraperitoneal administration of diphtheria toxin (DT) to induce mast cell depletion.
• Flow cytometry, histological analysis, and passive cutaneous anaphylaxis assays to assess mast cell reduction and specificity.

Main Results:

• DT treatment in Mcpt5/Cma1^DTR/+ mice achieved near-complete mast cell depletion (97.7%-100%) in multiple tissues.
• Passive cutaneous anaphylaxis confirmed mast cell deficiency in the ear.
• Minimal impact on other cell types, with only a small percentage of marginal zone B cells affected.

Conclusions:

• The Mcpt5/Cma1^DTR/+ mouse model allows for the conditional and near-complete depletion of all mast cell populations.
• This model is a valuable tool for in vivo research on mast cell functions without significant off-target effects.