Impaired B-lymphopoiesis, myelopoiesis, and derailed cerebellar neuron migration in CXCR4- and SDF-1-deficient mice

TLDR

SDF‑1 and its receptor CXCR4 regulate leukocyte and hematopoietic precursor migration, pre‑B cell proliferation, and act as a coreceptor for T‑tropic HIV‑1, with a unique receptor‑ligand selectivity among chemokines. CXCR4‑deficient mice die perinatally and exhibit severe B‑ and myelo‑cell deficiencies, normal T‑cell development, and cerebellar malformations, with identical phenotypes seen in SDF‑1‑deficient mice, underscoring a monogamous CXCR4–SDF‑1 relationship.

Abstract

The chemokine stromal cell-derived factor 1, SDF-1, is an important regulator of leukocyte and hematopoietic precursor migration and pre-B cell proliferation. The receptor for SDF-1, CXCR4, also functions as a coreceptor for T-tropic HIV-1 entry. We find that mice deficient for CXCR4 die perinatally and display profound defects in the hematopoietic and nervous systems. CXCR4-deficient mice have severely reduced B-lymphopoiesis, reduced myelopoiesis in fetal liver, and a virtual absence of myelopoiesis in bone marrow. However, T-lymphopoiesis is unaffected. Furthermore, the cerebellum develops abnormally with an irregular external granule cell layer, ectopically located Purkinje cells, and numerous chromophilic cell clumps of abnormally migrated granule cells within the cerebellar anlage. Identical defects are observed in mice lacking SDF-1, suggesting a monogamous relationship between CXCR4 and SDF-1. This receptor-ligand selectivity is unusual among chemokines and their receptors, as is the function in migration of nonhematopoietic cells.