C-KIT Expression in Orbital Cavernous Venous Hemangiomas.

Orbital (slow flow) cavernous venous hemangiomas (OCVH) are the most common benign orbital tumors in adults. The c-KIT is a tyrosine kinase receptor, which is expressed on several types of cells, is thought to play a key role in tumor pathogenesis. The purpose of this study was to evaluate the presence of the receptor c-KIT in OCVH.

Identification and Characterization of Two Human Monocyte-Derived Dendritic Cell Subpopulations with Different Functions in Dying Cell Clearance and Different Patterns of Cell Death.

Human monocyte-derived dendritic cells (mdDCs) are versatile cells that are used widely for research and experimental therapies. Although different culture conditions can affect their characteristics, there are no known subpopulations. Since monocytes differentiate into dendritic cells (DCs) in a variety of tissues and contexts, we asked whether they can give rise to different subpopulations.

Dissociation between mature phenotype and impaired transmigration in dendritic cells from heparanase-deficient mice.

To reach the lymphatics, migrating dendritic cells (DCs) need to interact with the extracellular matrix (ECM). Heparanase, a mammalian endo-β-D-glucuronidase, specifically degrades heparan sulfate proteoglycans ubiquitously associated with the cell surface and ECM. The role of heparanase in the physiology of bone marrow-derived DCs was studied in mutant heparanase knock-out (Hpse-KO) mice.

Constitutive neutrophil apoptosis: regulation by cell concentration via S100 A8/9 and the MEK-ERK pathway.

Programmed cell death (PCD) is a fundamental mechanism in tissue and cell homeostasis. It was long suggested that apoptosis regulates the cell number in diverse cell populations; however no clear mechanism was shown. Neutrophils are the short-lived, first-line defense of innate immunity, with an estimated t = 1/2 of 8 hours and a high turnover rate.

iC3b-opsonized apoptotic cells mediate a distinct anti-inflammatory response and transcriptional NF-kappaB-dependent blockade.

In recent years, it has become apparent that the removal of apoptotic cells by macrophages and DC is not only noninflammatory, but also immune-inhibitory, in most although not all circumstances. Complement may be involved in the uptake of apoptotic cells via direct binding of bridging factors in some physiological circumstances, by opsonization and engagement of the complement receptors. In the current study, we use a complement-dependent system of apoptotic cell clearance by human-derived macrophages and DC.

Calcium, leukocyte cell death and the use of annexin V: fatal encounters.

One hallmark of programmed cell death (PCD) is redistribution of phosphatidylserine (PS) to the plasma membrane's outer leaflet. Annexin V is widely used in cell death research due to its calcium-dependent ability to bind phosphatidylserine, thus marking apoptotic cells. However, calcium is invariably used at high concentrations in annexin V staining, at doses that can induce cell death.

Apoptotic cell thrombospondin-1 and heparin-binding domain lead to dendritic-cell phagocytic and tolerizing states.

Apoptotic cells were shown to induce dendritic cell immune tolerance. We applied a proteomic approach to identify molecules that are secreted from apoptotic monocytes, and thus may mediate engulfment and immune suppression. Supernatants of monocytes undergoing apoptosis were collected and compared using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and differentially expressed proteins were identified using tandem mass spectrometry.