Human IgE mediates stimulus secretion coupling in rat basophilic leukemia cells transfected with the alpha chain of the human high-affinity receptor.

Cell surface expression of the alpha chain of the human (h) Fc epsilon receptor type 1 (Fc epsilon R1) can be observed following stable transfection of RBL-2H3 cells with the h alpha chain of the Fc epsilon R1 complex. Association and dissociation constants for hIgE are similar to those previously reported for the ligand and its receptor. The demonstration of mediator release following the cross-linking of hFc epsilon R1 alpha by hIgE and antigen or anti-hFc epsilon R1 alpha antibody suggests that this system will assist the identification of structural motifs and specific amino acids that are involved in the generation of the signal(s) that will initiate and/or propagate the secretion of mediators from mast cells and basophils.