Chronic allergen challenge induces bronchial mast cell accumulation in BALB/c but not C57BL/6 mice and is independent of IL-9.
As genetically engineered mutant mice deficient in single genes are usually generated on a C57BL/6 background, to study mast cell trafficking in mutant mice, we initially investigated whether mast cells accumulated in bronchi in C57BL/6 mice challenged with OVA allergen acutely or chronically for 1 to 3 months. The total number of bronchial mast cells were quantitated using toluidine blue staining in airways of different sizes, i.e. , small (<90 microm), medium (90-155 microm), or large (>150 microm) airways. Non-OVA challenged and acute OVA challenged mice (C57BL/6 and BALB/c) had no detectable bronchial mast cells. Chronic OVA challenge in BALB/c mice for 1 or 3 months induced a significant increase in the number of bronchial mast cells in small-, medium-, and large-sized airways but minimal change in the number of bronchial mast cells in C57BL/6 mice. Both BALB/c and C57BL/6 mice developed significant lung eosinophilia following acute or chronic OVA challenge. Studies of IL-9-deficient mice on a BALB/c background demonstrated a significant increase in the number of bronchial mast cells in IL-9-deficient mice suggesting that IL-9 was not required for the bronchial accumulation of mast cells. Overall, these studies demonstrate that the chronic OVA challenge protocol we have utilized in BALB/c mice provides a model to study the mechanism of bronchial mast cell accumulation and that bronchial mast cell accumulation in chronic OVA challenged mice is independent of IL-9 in this model.
Pae
Suzan
S
Department of Medicine, University of California San Diego, San Diego, CA, USA.
Cho
Jae Youn
JY
Dayan
Shanna
S
Miller
Marina
M
Pemberton
Alan D
AD
Broide
David H
DH
D000485:Allergens / Q000008:administration & dosage*; D000818:Animals; D001249:Asthma / Q000209:etiology / Q000276:immunology / Q000473:pathology; D001980:Bronchi / Q000276:immunology* / Q000473:pathology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology; D004195:Disease Models, Animal; D005260:Female; D016906:Interleukin-9 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008407:Mast Cells / Q000276:immunology* / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology; D011657:Pulmonary Eosinophilia / Q000209:etiology / Q000276:immunology / Q000473:pathology; D013045:Species Specificity
D000485:Allergens; D016906:Interleukin-9; D010047:Ovalbumin