XBP1, a determinant of the eosinophil lineage

Abstract

Targeted deletion of the transcription factor XBP1 in hematopoietic stem cells selectively prevents eosinophil maturation in the bone marrow without affecting other immune lineages.

Figure 1. XBP1 is required for eosinophil differentiation

Deletion of XBP1 in HSCs prevents granulopoiesis in EoPs, inducing apoptosis and a profound eosinophil deficiency. Other immune cells are unaffected in number although their functionality remains to be examined. In mouse EoPs, defined by the expression of IL-5Rα (immature and matured cells) and CCR3 (matured cells), develop from GMPs. HSC, hematopoietic stem cell; CLP, common lymphoid progenitor; CMP, common myeloid progenitor; Baso, basophil; Neut, neutrophil; B, B cell; T, T cell; NK, natural killer cell; Mono, monocyte; EoP, Eosinophil progenitor; GMP, granulocyte-monocyte progenitor; IL-5Rα, IL-5 receptor alpha; CCR3, CC chemokine receptor 3.