Immunoglobulin E-mediated anaphylaxis activates nuclear factor kappaB in rat small intestine.

OBJECTIVE AND

DESIGN

Since IgE-dependent reactions induce the inducible isoform of NO synthase, we postulated the involvement of the transcription factor NF-kappaB.

MATERIALS: 72 Wistar rats were divided into 6 groups and used to study the hemorrhagic necrosis of the small intestine elicited by anaphylaxis.

TREATMENT: Passive anaphylaxis was produced by i.p. sensitization with IgE anti-dinitrophenyl monoclonal antibody and i.v. challenge with the cognate antigen.

METHODS

Competitive PCR was used to assay the expression of p50 subunit of NF-kappaB. kappaB-binding activity was assayed by electrophoretic mobility shift assay.

RESULTS

The PCR assay showed a time-dependent increase of mRNA coding for the p50 subunit of NF-kappaB, which was maximal 1 h after challenge (40+/-3, versus 230+/-32 fM, mean +/- SEM) and decreased to prechallenge level at 4h. kappaB-binding activity was also increased.

CONCLUSIONS

IgE-mediated reactions trigger a pathway for nuclear signaling that seems to be related to the intermediate/late response of the allergic reaction.