Expression and role of E-cadherin and CD103β7 (αEβ7 integrin) on cultured mucosal-type mast cells

Mucosal-type mast cells (MMC) in the respiratory and/or gut epithelium play pivotal roles in the development of allergic inflammation and nematode clearance. To determine the role of E-cadherin and alpha E beta 7 integrin in MMC localization to the epithelium, we analyzed the epithelial binding of two types of mouse bone marrow-derived mast cells: S3-BMMC, which developed in medium containing stem cell factor (SCF) plus IL-3, and S39T-BMMC, which developed with SCF, IL-3, IL-9 and TGF-beta 1. The latter cells were more similar to mature MMC than the former in terms of mouse mast cell protease (mMCP)-1 expression. FACS analyses revealed that S3-BMMC expressed E-cadherin and beta 7 integrin but not alpha E integrin, whereas S39T-BMMC expressed alpha E beta 7 integrin as well as E-cadherin. Mn2+ promoted adhesion of S39T-BMMC to the monolayer of E-cadherin(+)F9 cells. The adhesion was suppressed significantly by the combined addition of blocking antibodies against integrin aE and E-cadherin, whereas either blocking antibody alone failed to do so. S3-BMMC adhesion was suppressed by E-cadherin blocking antibody but not by aE blocking antibody. These results suggested that E-cadherin and alpha E beta 7 integrin, which are expressed on MMC-analog S39T-BMMC, play an important role in mast cell-epithelial cell interaction through homophilic as well as heterophilic binding to the epithelial E-cadherin molecule.