[Recombinant adenovirus type 5 does not aggravate asthma symptoms in a mouse model of ovalbumin-induced asthma]

Objective To explore the effect of recombinant adenovirus type 5 (rAd5) on a mouse model of ovalbumin (OVA)-induced asthma. Methods Sixty female C57BL/6 mice (6-8 weeks old and 18-20 g) were randomly divided into 4 groups: healthy control group, rAd5 control group, OVA asthma control group and OVA asthma group with rAd5 immunization. 15 mice in each group. The mice in the OVA asthma control group and the OVA asthma group with rAd5 immunization were sensitized by intraperitoneal injection of 50 μg OVA emulsified in 2 mg of aluminum potassium sulfate on day 0, 7 and 14; subsequently, the mice in the two groups were exposed to OVA aerosol challenge for 3 consecutive days (on day 42, 43 and 44). Meanwhile, mice in the healthy control group and the rAd5 control group were given an equal volume of normal saline. What's more, mice in the OVA asthma group with rAd5 immunization and the rAd5 control group were immunized intramuscularly with 2.5×10⁹ viral particles (VP) of rAd5 vectors on day 21, and were boosted intranasally with the same dose of rAd5 vectors on day 35. All mice were euthanized within 48 hours after the last challenge. The airway hyper-responsiveness (AHR) of mice was measured by single-chamber, whole-body plethysmography. The blood was obtained, the samples of bronchoalveolar lavage fluid (BALF) were collected, and lung tissues were prepared for HE and PAS staining. The levels of interleukin-4 (IL-4), IL-5, IL-13 in BALF and total IgE in serum were detected by ELISA. Results Compared with the healthy control group and the rAd5 control group, the pulmonary inflammation and mucus production significantly increased in the OVA asthma control group and the OVA asthma group with rAd5 immunization. The levels of IL-4, IL-5, IL-13 in BALF, total serum IgE and the AHR were also significantly enhanced in the OVA asthma control group and the OVA asthma group with rAd5 immunization. However, no significant difference was showed between the OVA asthma control group and the OVA asthma group with rAd5 immunization. Conclusion The use of recombinant adenovirus type 5 does not exacerbate asthma symptoms in a mouse model of OVA-induced asthma.