Ameliorating effect of CpG-ODN (oligodeoxynucleotide) against radiation-induced lung injury in mice

While radiation-induced lung injury (RILI) is known to be progressed by Th2 skewed, pro-inflammatory immune response, there have been few therapeutic attempts through Th1 immune modulation. We investigated whether the immunostimulant CpG-oligodeoxynucleotide (CpG-ODN) would be effective against RILI by way of measuring reactive oxygen species (ROS) and nitric oxides (NO), histopathology, micro-three-dimensional computer tomography (CT), and cytokine profiling. We found that KSK CpG-ODN (K-CpG) significantly reduced histopathological fibrosis when compared to the positive control (PC) group (p < 0.01). The levels of ROS production in serum and splenocyte of PC group were significantly higher than that of K-CpG group (p < 0.01). The production of nitric oxide (NO) in CpG-ODNs group was higher than that of PC group. Last, cytokine profiling illustrated that the protein concentrations of Th1-type cytokines such as IL-12 and TNF-α as well as Th2-type cytokine IL-5 in K-CpG group inclined to be significantly (p < 0.001 or p < 0.01) higher than those of in PC group. Collectively, our study clearly indicates that K-CpG is effective against RILI in mice by modulating the innate immune response. To our knowledge, this is the first note on anti-RILI effect of human type, K-CpG, clinically implying the potential of immunotherapy for RILI control.