Search results for "Myeloid Cell"

Increased frequencies of CD11b+CD33+CD14+HLA-DRlowmyeloid-derived suppressor cells are an early event in melanoma patients

2014

Myeloid-derived suppressor cells (MDSC) are a heterogeneous cell population characterized by immunosuppressive activity. Elevated levels of MDSC in peripheral blood are found in inflammatory diseases as well as in malignant tumors where they are supposed to be major contributors to mechanisms of tumor-associated tolerance. We investigated the frequency and function of MDSC in peripheral blood of melanoma patients and observed an accumulation of CD11b(+) CD33(+) CD14(+) HLA-DR(low) MDSC in all stages of disease (I-IV), including early stage I patients. Disease progression and enhanced tumor burden did not result in a further increase in frequencies or change in phenotype of MDSC. By investig…

TRAIL-induced apoptosis of hepatocellular carcinoma cells is augmented by targeted therapies

2009

AIM: To analyze the effect of chemotherapeutic drugs and specific kinase inhibitors, in combination with the death receptor ligand tumor necrosis factor-related apoptosis inducing ligand (TRAIL), on overcoming TRAIL resistance in hepatocellular carcinoma (HCC) and to study the efficacy of agonistic TRAIL antibodies, as well as the commitment of antiapoptotic BCL-2 proteins, in TRAIL-induced apoptosis. METHODS: Surface expression of TRAIL receptors (TRAIL-R1-4) and expression levels of the antiapoptotic BCL-2 proteins MCL-1 and BCL-xL were analyzed by flow cytometry and Western blotting, respectively. Knock-down of MCL-1 and BCL-xL was performed by transfecting specific small interfering RNA…

Intrahepatic myeloid-cell aggregates enable local proliferation of CD8+T cells and successful immunotherapy against chronic viral liver infection

2013

Chronic infection is difficult to overcome because of exhaustion or depletion of cytotoxic effector CD8(+) T cells (cytotoxic T lymphoytes (CTLs)). Here we report that signaling via Toll-like receptors (TLRs) induced intrahepatic aggregates of myeloid cells that enabled the population expansion of CTLs (iMATEs: 'intrahepatic myeloid-cell aggregates for T cell population expansion') without causing immunopathology. In the liver, CTL proliferation was restricted to iMATEs that were composed of inflammatory monocyte-derived CD11b(+) cells. Signaling via tumor-necrosis factor (TNF) caused iMATE formation that facilitated costimulation dependent on the receptor OX40 for expansion of the CTL popu…

2015

AbstractTriggering receptor expressed on myeloid cells (TREM)-1 plays an important role in innate immune responses and is upregulated under infectious as well as non-infectious conditions. In addition, a soluble TREM-1 variant (sTREM-1) is detectable in sera or bronchoalveolar-lavage fluids from patients. Currently, various studies are difficult to compare, since the methods of detection by enzyme-linked immunosorbent assays (ELISA) vary among different research groups. In this study, we compared three different s-TREM-1 specific ELISAs and identified individual assay characteristics finding notable differences in sTREM-1 concentrations in part depending on the employed buffers. Investigati…

Role of PRRs (TLR2 and Dectin-1) in hematopoietic stem and progenitor cell differentiation: implications in protection against Candida albicans infec…

2020

Detection of infection by hematopoietic stem and progenitor cells (HSPCs) is essential to replace myeloid cells consumed during the immune response. HSPCs express some functional pattern recognition receptors involved in the recognition of Candida albicans. In this context, our group has previously demonstrated that C. albicans yeasts induce proliferation and differentiation of HSPCs via TLR2 and Dectin-1. In the present PhD thesis, we used in vitro and ex vivo models of HSPC differentiation to investigate the functional consequences for mature myeloid cells of exposure of HSPCs to PAMPs or C. albicans yeasts. In vitro experiments show that murine HSPCs continuously exposed to TLR2 or TLR4 …