Differential roles for the IL-9/IL-9 receptor α-chain pathway in systemic and oral antigen-induced anaphylaxis

Parenteral antigen-induced murine systemic anaphylaxis is mediated by both IgG- and IgE-dependent pathways, and both can occur independently of IL-9/IL-9R signaling. In contrast, oral antigen-induced intestinal and systemic anaphylaxis is strictly IgE mediated and requires IL-9/IL-9R signaling. These studies indicate differential involvement of the IL-9/IL-9R pathway in systemic and oral antigen-induced anaphylaxis.