J Korean Med Sci.  2000 Jun;15(3):265-272. 10.3346/jkms.2000.15.3.265.

BCG infection during pre-sensitization or even post-sensitization inhibits airway sensitivity in an animal model of allergic asthma

• Koh YI
• Choi IS
• Park SC
• Kang KW

• KMID: 1128622
• DOI: http://doi.org/10.3346/jkms.2000.15.3.265

Abstract

The objective of this study is to investigate whether BCG infection before, during or after sensitization suppresses allergen-induced airway hyperresponsiveness and eosinophilic inflammation in allergic asthma rats, and to determine the required dose of BCG to induce such an inhibition. Eighty-seven Sprague-Dawley (SD) rats were sensitized and provoked with ovalbumin (OA). A pretreatment of 6 x 10(4) or 6 x 10(5) colony forming units (CFUs) of BCG or saline was done at four different times: 3 days before sensitization, at sensitization, 3 days before provocation, or at provocation. The assessment of tracheal smooth muscle (TSM) responsiveness to electrical field stimulation or acetylcholine (ACh) and bronchoalveolar lavage (BAL) were performed 1 day after OA provocation. Doses of 6 x 10(4) CFUs inhibited TSM sensitivity of rats infected 3 days before sensitization or at sensitization, but not 3 days before provocation or at provocation. However, doses of 6 x 10(5) CFUs significantly inhibited not only the airway eosinophilia of rats infected 3 days before sensitization or at sensitization, but also the TSM sensitivity of rats infected 3 days before provocation or at provocation. In conclusion, BCG infection suppresses the development of sensitivity of airway smooth muscle and airway eosinophilic inflammation in allergic asthma rats. Furthermore, a relatively high dose of BCG infection inhibits airway sensitivity, even after allergen sensitization.

Keyword

BCG Vaccine; Asthma; Bronchial Hyperreactivity; Eosinophilia

MeSH Terms

Animal
Asthma/immunology*
BCG Vaccine/immunology*
Disease Models, Animal
Disease Models, Animal
Eosinophils/immunology
Leukocyte Count
Lung/immunology*
Male
Muscle, Smooth, Vascular/immunology
Rats
Rats, Sprague-Dawley
Time Factors
Vaccination