Cytokine-mast cell interactions: relevance to IgE-mediated chemical allergy

Recent work has shown that certain cytokines (inducible secreted proteins) are potent regulators of mast cell development and secretory function. We know also that sensitization of mice to chemical allergens induces T cell-dependent immune responses in which cytokines play an important role. Combining these observations, we postulate that in vivo T cell responses might influence, via the production of cytokines, the behaviour of mast cells in situ. In support of this hypothesis we have found that mast cells isolated from chemical allergen-sensitized mice show enhanced responsiveness to IgE-dependent activation in vitro. This effect is seen with chemical allergens that are either contact or respiratory sensitizers in man. Although respiratory and contact allergens cannot be distinguished according to their ability to modulate mouse mast cell function in vivo, they can be separated on the basis of their differential ability to induce specific IgE-dependent mast cell sensitization. In conclusion, the mouse may offer a useful model for investigating and predicting the potential of chemicals to act as mast cell promoting agents and/or respiratory sensitizers.