A study on the protective effects of CpG ODN-induced mucosal immunity against lung injury in a mouse ARDS model

Abstract

This study aims to determine the feasibility of using oligodeoxynucleotides with unmethylated cytosine-guanine dinucleotide sequences (CpG ODN) as an immunity protection strategy for a mouse model of acute respiratory distress syndrome (ARDS). This is a prospective laboratory animal investigation. 20-week old BALB/c mice in Animal research laboratory were randomized into groups. An ARDS model was induced in mice using lipopolysaccharides. CpG ODN was intranasally and transrectally immunized before or after the 3rd and 7th day of establishing the ARDS model. Mice were euthanized on day seven after the 2nd immunization. Then, retroorbital bleeding was carried, out and the chest was rapidly opened to collect the trachea and tissues from both lungs for testing. CpG ODN significantly improved the pathologic impairment in mice lung, especially after the intranasal administration of 50 ug. This resulted in the least severe lung tissue injury. Furthermore, IL-6 and IL-8 concentrations were lower, which was second to mice treated with the rectal administration of 20 g CpG ODN. In contrast, the nasal and rectal administration of CpG ODN in BALB/c mice before LPS immunization did not appear to exhibit any significant protective effects. In conclusion, the intranasal administration of CpG ODN may be is a potential treatment approach to ARDS. More studies are needed to further determine the protective mechanism of CpG ODN.