Cell adhesion molecule 1 (CADM1) on mast cells promotes interaction with dorsal root ganglion neurites by heterophilic binding to nectin-3

Cell adhesion molecule 1 (CADM1) on mast cells promotes attachment and communication with neurons by homophilic binding. However, we found that mast cell CADM1 was responsible for both the attachment of mast cells to dorsal root ganglia (DRG) neurites and their calcium responses to activated DRG neurites, despite the low expression of CADM1 in DRG. Instead, nectin-3 was expressed on DRG neurons and localized to regions of cell-cell contact. A neutralizing antibody to nectin-3 inhibited both mast cell attachment and subsequent calcium responses. This suggests that heterophilic binding between CADM1 and nectin-3 mediates functional DRG-mast cell interactions in vitro.