Rapid SCIT for induction of HSE allergy in murine asthma model
The SCIT model for Humulus pollen allergy was developed on the basis of the asthma model established as shown in Fig. 1A, and in combination with methods described by Leonie et al.[18]. The detailed process was as follows (Fig. 1B): 30 BALB/c mice aged 6–8 weeks were randomly divided into control, vehicle, and treatment groups (10 mice per group). Mice in the vehicle and treatment groups were sensitized by SC injection with 25 µg of HSE adsorbed to alum adjuvant on days 1, 8, and 15; they were then challenged with atomized HSE on days 21–23 to induce symptoms. SCIT was started on day 25, comprising eight treatments every other day. In the treatment group, mice received an SC injection of 300 µg of HSE (2 μg/μL, 150 μL) into the neck. Mice in the vehicle group received an SC injection of 150 μL of PBS. To investigate the effectiveness of SCIT, mice in the vehicle and treatment groups were re-challenged with an HSE aerosol on days 43–49. In parallel, control mice received saline, rather than HSE, at all steps. On day 50, AHR to Mch was assessed in all animals. One day later, all mice were sacrificed. Sera were obtained for measurement of specific IgE levels and specific IgG2a levels; other samples for analysis were harvested as described above.