BCG inoculation and corticosteroid sensitivity.

Purpose: This study was conducted to clarify the relationship between Bacille de Calmette-Guérin (BCG) inoculation and corticosteroid sensitivity.

Methods: Lewis and WKAH rats were inoculated with BCG vaccine weekly beginning at six weeks of age. At 15 weeks, spleen cells were cultured with PHA and betamethasone for 24 hours. RNA was extracted and interleukin-2 gene expression was measured using a real-time PCR method.

Results: BCG inoculation sensitized Lewis rats, but not WKAH rats, to PPD stimulation. In Lewis rats, IL-2 gene expression increased after BCG inoculation, while betamethasone suppressed IL-2 expression. In WKAH rats, the expression of IL-2 was not affected by repeated BCG inoculations and betamethasone had no effect on BCG-treated rats.

Conclusion: BCG inoculation may affect steroid sensitivity in some strains of rats.