Basophil and eosinophil differentiation in allergic reactions

Abstract

Basophil and eosinophil participation in allergic reactions constitutes a hallmark of this type of inflammatory state. Mechanisms underlying the accumulation of these cells in tissues where allergen is present include the effect of cytokines and other inflammatory mediators on the egress from blood and migration of these cells into the tissue. Much progress has been made recently in the understanding of in vitro chemotactic and adherence mechanisms putatively involved in the accumulation of the mature basophil and eosinophil in IgE-dependent reactions in vivo? A concept we have developed in our studies over the past decade is that the bone marrow, through the release of progenitors into the peripheral blood, contributes a pool of differentiating cells, which accumulate in response to signals from allergic inflamed tissues. 2s In this review we summarize the basis for this concept, citing both basic and applied studies and expanding on the evidence supporting the progenitor hypothesis for accumulation of basophils and eosinophils by using recently acquired information in an animal model and in human beings.