Long-term modulatory effect of Mycobacterium vaccae treatment on histopathologic changes in a murine model of asthma.
BACKGROUND
Mycobacteria are being investigated for modulation of inflammation in asthma and atopic disorders by eliciting particularly strong protective TH1 immune responses.


OBJECTIVE
To investigate the long-term effects of intratracheally administered Mycobacterium vaccae on an experimental murine model of asthma.


METHODS
BALB/c mice were placed in 4 groups: long-term M. vaccae, M. vaccae, asthma, and control groups. All groups but controls were sensitized intraperitoneally and challenged intratracheally with ovalbumin. The long-term M. vaccae and M. vaccae groups were treated with M. vaccae intratracheally simultaneously during challenges. Finally, mice in the long-term M. vaccae group were rechallenged with ovalbumin nebulization 24 days later. Evaluations of lung histopathologic findings and serum cytokine levels were performed.


RESULTS
Comparison of the long-term M. vaccae group with the asthma model group revealed that the number of hyperplasic goblet cells in small and large airways (small airway: P < .05; large airways: P < .01) and thickness of basement membrane in large airways were significantly less in the long-term M. vaccae group. Furthermore, numbers of hyperplasic goblet cells in small airways (P < .05) and basement membrane in the large airway (P < .05), as well as inflammation in small airways (P < .01), were significantly less in the M. vaccae group when compared with the asthma model group. Interferon-gamma secretion from splenocytes of the M. vaccae group was significantly higher than the asthma model and long-term M. vaccae groups.


CONCLUSIONS
Intratracheal administration of M. vaccae exerted a long-lasting ameliorating effect on airway histopathologic features of a murine asthma model.
Yazi
Didem
D
Division of Pediatric Allergy and Immunology, Marmara University, Istanbul, Turkey.
Akkoc
Tunc
T
Ozdemir
Cevdet
C
Yesil
Ozlem
O
Aydogan
Metin
M
Sancak
Recep
R
Bahceciler
Nerin N
NN
Barlan
Isil B
IB
D000818:Animals; D001249:Asthma / Q000276:immunology* / Q000473:pathology* / Q000517:prevention & control; D001485:Basement Membrane / Q000473:pathology; D016207:Cytokines / Q000276:immunology; D004195:Disease Models, Animal; D005260:Female; D020397:Goblet Cells / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009130:Muscle, Smooth / Q000473:pathology; D009161:Mycobacterium / Q000276:immunology*; D010047:Ovalbumin / Q000276:immunology; D013997:Time Factors
D016207:Cytokines; D010047:Ovalbumin