ABSTRACT
Objective: To investigate the effect of maternal exposure to lipopolysaccharide during pregnancy on allergic asthma in offspring in mice. Methods: Animal experimental research was carried out from June 2019 to June 2021.Pregnant C57BL/6J mice were randomly divided into 2 groups by intraperitoneal injection with 7 μg/kg lipopolysaccharide (LPS) or phosphate buffered saline (PBS) at day 15.5 of gestation. After birth, 6 offspring were randomly chosen from each group at the age of 4 weeks, and stimulated with house dust mites (HDM) or PBS, further divided into 4 groups, such as LPS+PBS group, LPS+HDM group, PBS+PBS group, PBS+HDM group, with 3 mice in each group. The cough and wheezing were observed, the histological changes in lung tissue were examined after HE staining, and the expression of inflammatory factors including interleukin (IL)-4, IL-6, IL-17A, IL-23, interferon (IFN)-α and IFN-β in the lung tissue were detected by high-throughput liquid protein chip detection. T test or rank sum test was used for the comparison among these groups. Results: The asthma-like airway inflammation was more obvious in PBS+HDM group after stimulated by HDM than that in PBS+PBS group, nevertheless, this manifestation in LPS+HDM group was milder than that in PBS+HDM group. HE staining showed that inflammatory cell aggregation in the lung tissue in PBS+HDM group was significantly higher than that in PBS+PBS group (4.0 (3.5, 4.0) vs. 0 (0, 0.5), Z=2.02, P=0.043), while it was much lower in LPS+HDM group compared to PBS+HDM group (1.0 (0.5, 1.5) vs. 4.0 (3.5, 4.0), Z=1.99, P=0.046). High-throughput liquid protein chip detection of lung tissue showed that IL-6, IL-23 and IFN-β levels were significantly higher in PBS+HDM group when compared to those in PBS+PBS group ((114±3) vs. (94±4) ng/L, (210±4) vs. (173±7) ng/L, (113±2) vs. (94±4) ng/L, t=4.37, 4.84, 3.96, all P<0.05), while the levels of IL-6, IL-23, IFN-α, IFN-β in LPS+HDM group were significantly lower than those in PBS+HDM group ((87±5) vs. (114±3) ng/L, (171±7) vs. (210±4) ng/L, (16.1±0.6) vs. (20.9±0.3) ng/L, (95±1) vs. (113±2) ng/L, t=5.07, 5.07, 7.28, 7.47, all P<0.05). Conclusions: Prenatal low dose LPS exposure can reduce offspring's airway inflammatory reactions and prevent the development of allergic disease. Maternal infection during pregnancy may affect the occurrence and development of allergic asthma in offspring.