Modulation of CXC chemokine receptor expression and function in human neutrophils during aging in vitro suggests a role in their clearance from circulation.

In mice, differential regulation of CXC chemokine receptor expression in circulating polymorphonuclear neutrophils (PMNs) undergoing senescence results in homing to the bone marrow. However, the role of this compartment and of the chemokine receptor CXCR4 is still under discussion, and only scarce data exist about CXCR4 function in human PMN. In our study, we provide evidence that also in human neutrophils, expression (cell surface and mRNA), chemotactic and signaling functions of the homing-related chemokine receptor CXCR4 are upregulated during aging in vitro, independent of addition of stimulatory cytokines (TNF, IL-1, IL-8, G-CSF).

The Zygosaccharomyces bailii antifungal virus toxin zygocin: cloning and expression in a heterologous fungal host.

Zygocin, a monomeric protein toxin secreted by a virus-infected killer strain of the osmotolerant spoilage yeast Zygosaccharomyces bailii, kills a broad spectrum of human and phytopathogenic yeasts and filamentous fungi by disrupting cytoplasmic membrane function. The toxin is encoded by a double-stranded (ds)RNA killer virus (ZbV-M, for Z. bailii virus M) that stably persists within the yeast cell cytosol.

Transendothelial migration of hematopoietic progenitor cells. Role of chemotactic factors.

There is increasing evidence that hematopoietic stem cell mobilization and homing is regulated not only by adhesion molecules and cytokines, but also by chemotactic factors that support transendothelial migration across the bone marrow sinusoidal endothelium. Many receptors for chemotactic mediators belong to the family of G protein-coupled seven-transmembrane receptors (7-TMR). Signaling via G proteins, particularly Gi proteins, results in a chemotactic response of the cells towards a gradient of the corresponding ligand.

Chemotaxis and transendothelial migration of CD34(+) hematopoietic progenitor cells induced by the inflammatory mediator leukotriene D4 are mediated by the 7-transmembrane receptor CysLT1.

Recent studies suggest that bone marrow (BM)-derived chemotactic mediators such as chemokines play key roles in hematopoietic stem cell trafficking. Lipid mediators, particularly leukotrienes, are involved in leukocyte chemotaxis during inflammation but have also been detected in the normal BM. Therefore, the effects of leukotrienes on hematopoietic progenitor cells were analyzed.

Functional response of leukaemic blasts to stromal cell-derived factor-1 correlates with preferential expression of the chemokine receptor CXCR4 in acute myelomonocytic and lymphoblastic leukaemia.

The chemokine stromal cell-derived factor-1 (SDF-1) that is released by bone marrow (BM) stromal cells and contributes to stem cell homing may also play a role in the trafficking of leukaemic cells. We analysed SDF-1-induced intracellular calcium fluxes in leukaemic blasts from the peripheral blood of patients with newly diagnosed acute myeloid leukaemia (AML) and lymphoblastic leukaemia (B-lineage ALL), determined the effect of BM stromal cell-conditioned medium on in vitro transendothelial migration (TM) and measured expression of the SDF-1 receptor, CXCR4, by flow cytometry. AML FAB M1/2 blasts did not show calcium fluxes and TM was not stimulated.