Basophils and mast cells play critical roles for leukocyte recruitment in IgE-mediated cutaneous reverse passive Arthus reaction

Background: The pathogenic role of IgE has been implicated in a variety of allergic and inflammatory diseases. We have previously established an IgE-mediated cutaneous reverse passive Arthus model in which eosinophil infiltration is a prominent feature. This uniquely provides a model of type III hypersensitivity in which Fc classes of Ig that forms immune complex differentially determine the disease manifestation.

Objective: To investigate the mechanisms of how mast cells and basophils regulate this IgE-mediated Arthus reaction.

Methods: IgE-mediated cutaneous reverse passive Arthus reaction was induced in wild-type C57BL/6 or WBB6F1-+/+ mice and mast-cell-deficient WBB6F1-W/W(v) mice by intradermal injection of IgE anti-trinitrophenyl antibodies followed immediately by intravenous administration of trinitrophenyl bovine serum albumin. Basophils were depleted in vivo using anti-CD200R3 monoclonal antibody prior to the IC challenge.

Results: Hemorrhage and infiltration of eosinophils, neutrophils, and basophils were significantly reduced but were not completely abrogated in WBB6F1-W/W(v) mice compared with those in wild-type WBB6F1-+/+ mice. Wild-type C57BL/6 mice treated by basophil-depleting mAb also showed significantly decreased hemorrhage and inflammatory cell infiltration, especially that of eosinophils, compared with control mice. Furthermore, basophil depletion in WBB6F1-W/W(v) mice led to nearly complete inhibition of eosinophil recruitment. By contrast, basophil depletion did not further decrease neutrophil infiltration in WBB6F1-W/W(v) mice.

Conclusion: While mast cells play a central role, basophils also have an important function, especially for eosinophil recruitment, in IgE-mediated cutaneous reverse passive Arthus reaction.