IgE- and FcεRI-mediated migration of human basophils

Abstract

Local accumulation of basophils at inflammatory sites is observed in experimental antigen challenge and in allergic diseases. It is not fully known what factor(s) regulates local basophil influx in tissues, and it has not been determined whether antigens belong in a panel of basophil chemoattractants. This study was designed to elucidate whether IgE- and high-affinity receptor for IgE (FcεRI)-mediated stimulation can induce human basophil migration. The migration-inducing potency of an anti-FcεRI α-chain mAb, CRA-1, was examined on human basophils. CRA-1 mAb elicited significant migration of basophils. The migration-inducing potency of this mAb was maximal at 100 ng ml-1, and CRA-1 mAb at 100 ng ml-1 attracted ∼10% of total inoculated basophils above baseline levels after incubation for 2.5 h. Checkerboard analysis indicated that basophil migration induced by this mAb was mainly chemotactic and partially chemokinetic. An antigen, Der f 2, also induced migration of basophils from Der f-sensitive subjects. Basophils mixed with 1 ng ml-1 of CRA-1 mAb showed an exaggerated migration response to eotaxin, indicating that FcεRI cross-linkage enhances basophil migration to other chemoattractants. Induction of basophil migration by IgE- and FcεRI-cross-linking stimulation may, at least in part, explain the pathogenesis of local basophil accumulation clinically observed in allergic diseases such as asthma. © The Japanese Society for Immunology. 2005. All rights reserved.