The integrins α4β7 and α4β1 mediate adhesion to the mucosal addressin cell adhesion molecule-1 (MAdCAM-I) and the vascular cell adhesion molecule-1 (VCAM-1) and are important in T cell and allergic inflammatory reactions in the rat. The relative contributions of α4β7 and α4β1 in these reactions is unknown. To examine the role of α4β7 in the rat a new mAb, TA-6, was developed. TA-6 inhibited adhesion to MAdCAM-1 but not to VCAM-1, a characteristic of α4β7 adhesion, and immunofluorescence and immunoprecipitation studies were compatible with binding to α4β7. TA-6 blocked rat lymphocyte adhesion to mesenteric lymph nodes and T cell migration to mucosal lymphoid tissues and it bound to rat mucosal mast cells. TA-6 did not inhibit lymphocyte adhesion to peripheral lymph nodes and T cell migration to peripheral lymphoid tissues or cutaneous inflammatory sites, and was not expressed on connective tissue mast cells.
ASJC Scopus subject areas
- Cell Biology