Abstract: ObjectiveTo identify the immunological characteristics of the recombinant major pollen allergen pTSX2ofHumulus
scandens and evaluate its safety in immunotherapy of allergic asthma in mice. MethodsWestern blotting was used to
characterize the immunological properties of pTSX2, and its immunogenicity in normal mice was evaluated by detecting sIgG
and sIgE levels. The mouse models of allergic asthma were immunized with pTSX2and examined for sIgE and sIgG levels,
total cells and eosinophils percentage in BALF, interleukin-4 (IL-4) andinterferon-γ(IFN-γ) levels inBALFandspleen
homogenate, and changes in lung pathologies.ResultsWestern blotting showed that pTSX2reacted with the majority (about
70% ) of sera from patients allergic to Humulus pollen. In normal mice, pTSX2mainly induced the production of sIgG. In
mouse models of allergic asthma, intervention with pTSX2caused a significant reduction of sIgE and an increase of sIgG (P<
0.05), significantly decreased the total cells and eosinophils in BALF (P<0.05), obviously lowered IL-4but increasedIFN-γin
BALF and spleen homogenate (P<0.05), and diminished inflammatory cell infiltration and percentage of eosinophils in the
lung tissues. ConclusionpTSX2shows a definite therapeutic effect and safety in the treatment of allergic asthma in mice
possibly by inhibiting sIgE and inducing sIgG production, suppressing airway allergic inflammation and regulating the
balance between Thl and Th2.