Bacillus Calmette-Guerín vaccination: a novel therapeutic approach to preventing hyperoxic lung injury.

Objective: A growing body of evidence suggests that vaccinations play a role in the normal maturation of the immune system and in both the development and balance of immune regulatory pathways that can impact health later in life. This study aimed to evaluate the effects of Bacillus Calmette-Guerín (BCG) vaccine on the hyperoxia-induced neonatal rat lung injury.

Methods: Four groups were defined as hyperoxia-exposed BCG-vaccinated, hyperoxia-exposed placebo, room air-exposed control and room air-exposed BCG-vaccinated group. The validity of the hyperoxia-induced lung injury model used in this study was confirmed by histological and immunohistochemical test. Gene expression related with cytokine and growth factor was evaluated by real-time reverse transcription polymerase chain reaction.

Result: The mean alveolar surface area and quantification of secondary crest formation in the oxygen-exposed placebo group was significantly lower than that of the oxygen-exposed BCG-vaccinated group. Compared to the oxygen-exposed placebo group, the oxygen-exposed BCG-vaccinated group showed a significantly decreased alveolar septal fibrosis and smooth muscle actin expression. The expression of genes VEGF, FGF-BP1, IL-13, and NFκB1 (p50) in the lungs of the hyperoxia-exposed BCG-vaccinated group was significantly higher than that of the hyperoxia-exposed placebo group.

Conclusion: Results suggest that BCG vaccination can protect against neonatal hyperoxic lung injury. These benefits may be interpreted to coincide with its immunomodulatory effects on pro-inflammatory and anti-inflammatory cytokine balance and expression of growth factors.