搜索结果: 'methocult media formulations for mouse hematopoietic cells serum containing'

C-Type lectin receptor 5A (CLEC5A) is a spleen tyrosine kinase- (Syk-) coupled pattern recognition receptor expressed on myeloid cells and involved in the innate immune response to viral and bacterial infections. Activation of the CLEC5A receptor with pathogen-derived antigens leads to a secretion of proinflammatory mediators such as TNF-$\alpha$ and IL-6 that may provoke a systemic cytokine storm,and CLEC5A gene polymorphisms are associated with the severity of DV infection. In addition,the CLEC5A receptor was mentioned in the context of noninfectious disorders like chronic obstructive pulmonary disease (COPD) or arthritis. Altogether,CLEC5A may be considered as an innate immune checkpoint capable to amplify proinflammatory signals,and this way contributes to infection or to aseptic inflammation. In this study,we determined CLEC5A receptor expression on different macrophage subsets (in vitro and ex vivo) and the functional consequences of its activation in aseptic conditions. The CLEC5A surface expression appeared the highest on proinflammatory M1 macrophages while intermediate on tumor-associated phenotypes (M2c or TAM). In contrast,the CLEC5A expression on ex vivo-derived alveolar macrophages from healthy donors or macrophages from ovarian cancer patients was hardly detectable. Targeting CLEC5A on noninflammatory macrophages with an agonistic $\alpha$-CLEC5A antibody triggered a release of proinflammatory cytokines,resembling a response to dengue virus,and led to phenotypic changes in myeloid cells that may suggest their reprogramming towards a proinflammatory phenotype,e.g.,upregulation of CD80 and downregulation of CD163. Interestingly,the CLEC5A agonist upregulated immune-regulatory molecules like CD206,PD-L1,and cytokines like IL-10,macrophage-derived chemokine (MDC/CCL22),and thymus and activation chemokine (TARC/CCL17) which are associated with an anti-inflammatory or a protumorigenic macrophage phenotype. In the absence of concomitant pathogenic or endogenous danger signals,the CLEC5A receptor activation did not amplify an autologous T cell response,which may represent a protective innate mechanism to avoid an undesirable autoimmune adaptive response. View Publication

The synthetic retinoid 6-[3-(adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437),which can bind to and activate the nuclear retinoic acid receptors beta and gamma (RARbeta/gamma),is a potent inducer of apoptosis in various cancer cell lines. However,this effect was reported to be independent of RARs. In this study,we compared and contrasted the potencies and mechanisms of action of CD437 and several other receptor-selective retinoids in induction of apoptosis and modulation of squamous differentiation in UMSCC22B human head and neck squamous cell carcinoma cell line. CD437 and the structurally related retinoid CD2325 exhibited almost equal potency in inducing apoptosis,whereas several other retinoids failed to induce apoptosis. The RAR-specific pan antagonist AGN193109 failed to suppress CD437-induced apoptosis,indicating that the induction of apoptosis by CD437 was RAR-independent. c-Fos expression was induced by CD437 and CD2325 that induced apoptosis in the cell line but not by other retinoids that failed to induce apoptosis,suggesting a role for c-Fos in CD437-induced apoptosis. At low concentration (0.01 microM),CD437 shared with several other receptor-selective retinoids the ability to suppress the mRNA levels of the squamous differentiation markers Spr1,involucrin,and cytokeratin 1. This effect of CD437 could be blocked by AGN193109. We conclude that CD437 can exert its effects in UMSCC22B human human head and neck squamous cell carcinoma cells by at least two mechanisms: RAR-mediated suppression of squamous differentiation and RAR-independent induction of apoptosis. View Publication

In order to develop a novel method of visualizing possible Ca(2+) signaling during the early differentiation of hESCs into cardiomyocytes and avoid some of the inherent problems associated with using fluorescent reporters,we expressed the bioluminescent Ca(2+) reporter,apo-aequorin,in HES2 cells and then reconstituted active holo-aequorin by incubation with f-coelenterazine. The temporal nature of the Ca(2+) signals generated by the holo-f-aequorin-expressing HES2 cells during the earliest stages of differentiation into cardiomyocytes was then investigated. Our data show that no endogenous Ca(2+) transients (generated by release from intracellular stores) were detected in 1-12-day-old cardiospheres but transients were generated in cardiospheres following stimulation with KCl or CaCl2,indicating that holo-f-aequorin was functional in these cells. Furthermore,following the addition of exogenous ATP,an inositol trisphosphate receptor (IP3R) agonist,small Ca(2+) transients were generated from day 1 onward. That ATP was inducing Ca(2+) release from functional IP3Rs was demonstrated by treatment with 2-APB,a known IP3R antagonist. In contrast,following treatment with caffeine,a ryanodine receptor (RyR) agonist,a minimal Ca(2+) response was observed at day 8 of differentiation only. Thus,our data indicate that unlike RyRs,IP3Rs are present and continually functional at these early stages of cardiomyocyte differentiation. View Publication

Bispecific antibodies directed against tumor-associated target antigens and to surface receptors mediating T-cell activation,such as the TCR/CD3 complex and the costimulatory receptor CD28,are capable of mediating T-cell activation resulting in tumor cell killing. In this study,we used the B-cell-associated antigens CD19 and CD20 as target structures on human leukemic cells. We found that a combination of bispecific antibody fragments (bsFab2) with target x CD3 and target x CD28 specificity induces vigorous autologous T-cell activation and killing of malignant cells in peripheral blood and bone marrow cultures from patients with chronic lymphocytic leukemia and follicular lymphoma. The bsFab2 targeting CD20 were considerably more effective than those binding to CD19. The colony-forming capacity of treated bone marrow was impaired due to large amounts of tumor necrosis factor alpha produced during bsFab2-induced T-cell activation. Neutralizing tumor necrosis factor alpha antibodies were found to reverse this negative effect without affecting T-cell activation and tumor cell killing. CD20 x CD28 bsFab2,when used alone rather than in combination,markedly improved the recognition of leukemic cells by allogeneic T cells. Therefore,these reagents may be capable of enhancing the immunogenicity of leukemic cells in general and,in particular,of increasing the antileukemic activity of allogeneic donor buffy coat cells in relapsed bone marrow transplanted patients. View Publication