METHODS: BABL/c mice were sensitized twice by intraperitoneal injection of HDM extracts and Al(OH)3 on day 1 and day 8. Then, the mice received challenge to induce airway inflammation by intratracheal instillation of HDM extracts on days 29-31. The treatment group received immunotherapy with oral HDM extracts ingestion before the challenge. All the mice were sacrificed on day 32 for bronchoalveolar inflammatory cytokines, mediastinal lymph node T cells, lung histology, and serum HDM-specific immunoglobulins analyses.
RESULTS: Upon HDM sensitization and following challenge, a robust Th2 cell response and eosinophilic airway inflammation were observed in mice of the positive control group. The mice treated with HDM extracts ingestion had decreased eosinophilic airway inflammation, suppressed HDM-specific Th2 cell responses in the mediastinal lymph nodes, and attenuated serum HDM-specific IgE levels.
CONCLUSIONS: Oral immunotherapy with HDM extracts ingestion was demonstrated to have a partial therapeutic effect in the murine model of allergic asthma. This study may serve as the basis for the further development of oral immunotherapy with HDM extracts in allergic asthma.