27 research outputs found
Oleate but not stearate induces the regulatory phenotype of myeloid suppressor cells
Tumor infiltrating myeloid cells play contradictory roles in the tumor
development. Dendritic cells and classical activated macrophages support anti-
tumor immune activity via antigen presentation and induction of pro-
inflammatory immune responses. Myeloid suppressor cells (MSCs), for instance
myeloid derived suppressor cells (MDSCs) or tumor associated macrophages play
a critical role in tumor growth. Here, treatment with sodium oleate, an
unsaturated fatty acid, induced a regulatory phenotype in the myeloid
suppressor cell line MSC-2 and resulted in an increased suppression of
activated T cells, paralleled by increased intracellular lipid droplets
formation. Furthermore, sodium oleate potentiated nitric oxide (NO) production
in MSC-2, thereby increasing their suppressive capacity. In primary polarized
bone marrow cells, sodium oleate (C18:1) and linoleate (C18:2), but not
stearate (C18:0) were identified as potent FFA to induce a regulatory
phenotype. This effect was abrogated in MSC-2 as well as primary cells by
specific inhibition of droplets formation while the inhibition of de novo FFA
synthesis proved ineffective, suggesting a critical role for exogenous FFA in
the functional induction of MSCs. Taken together our data introduce a new
unsaturated fatty acid-dependent pathway shaping the functional phenotype of
MSCs, facilitating the tumor escape from the immune system
Role of Myeloid-Derived Suppressor Cells in Amelioration of Experimental Autoimmune Hepatitis Following Activation of TRPV1 Receptors by Cannabidiol
Myeloid-derived suppressor cells (MDSCs) are getting increased attention as one of the main regulatory cells of the immune system. They are induced at sites of inflammation and can potently suppress T cell functions. In the current study, we demonstrate how activation of TRPV1 vanilloid receptors can trigger MDSCs, which in turn, can inhibit inflammation and hepatitis.Polyclonal activation of T cells, following injection of concanavalin A (ConA), in C57BL/6 mice caused acute hepatitis, characterized by significant increase in aspartate transaminase (AST), induction of inflammatory cytokines, and infiltration of mononuclear cells in the liver, leading to severe liver injury. Administration of cannabidiol (CBD), a natural non-psychoactive cannabinoid, after ConA challenge, inhibited hepatitis in a dose-dependent manner, along with all of the associated inflammation markers. Phenotypic analysis of liver infiltrating cells showed that CBD-mediated suppression of hepatitis was associated with increased induction of arginase-expressing CD11b(+)Gr-1(+) MDSCs. Purified CBD-induced MDSCs could effectively suppress T cell proliferation in vitro in arginase-dependent manner. Furthermore, adoptive transfer of purified MDSCs into naïve mice conferred significant protection from ConA-induced hepatitis. CBD failed to induce MDSCs and suppress hepatitis in the livers of vanilloid receptor-deficient mice (TRPV1(-/-)) thereby suggesting that CBD primarily acted via this receptor to induce MDSCs and suppress hepatitis. While MDSCs induced by CBD in liver consisted of granulocytic and monocytic subsets at a ratio of ∼2∶1, the monocytic MDSCs were more immunosuppressive compared to granulocytic MDSCs. The ability of CBD to induce MDSCs and suppress hepatitis was also demonstrable in Staphylococcal enterotoxin B-induced liver injury.This study demonstrates for the first time that MDSCs play a critical role in attenuating acute inflammation in the liver, and that agents such as CBD, which trigger MDSCs through activation of TRPV1 vanilloid receptors may constitute a novel therapeutic modality to treat inflammatory diseases
Zoledronic acid impairs myeloid differentiation to tumour-associated macrophages in mesothelioma
Background: Suppressive immune cells present in tumour microenvironments are known to augment tumour growth and hamper efficacy of antitumour therapies. The amino-bisphosphonate Zoledronic acid (ZA) is considered as an antitumour agent, as recent studies showed that ZA prolongs disease-free survival in cancer patients. The exact mechanism is a topic of debate; it has been suggested that ZA targets tumour-associated macrophages (TAMs). Methods: We investigate the role of ZA on the myeloid differentiation to TAMs in murine mesothelioma in vivo and in vitro. Mice were intraperitoneally inoculated with a lethal dose of mesothelioma tumour cells and treated with ZA to determine the effects on myeloid differentiation and survival. Results: We show that ZA impaired myeloid differentiation. Inhibition of myeloid differentiation led to a reduction in TAMs, but
Very small size proteoliposomes abrogate cross-presentation of tumor antigens by myeloid-derived suppressor cells and induce their differentiation to dendritic cells
„Antibiotic-stewardship“(ABS)-Strategien in der urologischen Praxis und Klinik
Antibiotics are effective and safe drugs which have saved millions of lives since their inception. The World Health organization (WHO) has identified increasing antibiotic resistance worldwide as one of the greatest health problems of our time. The most common indications for antibiotic therapy include urinary tract infections, but according to current data, a very high percentage of these are not treated in accordance with guidelines. To prevent the continuous selection of resistant bacteria, and undesirable or even dangerous side effects such as by avoiding damage to the patient's microbiome, strategies through antibiotic stewardship (ABS) are urgently needed. Especially for urologists in outpatient care, this requires new, innovative and sustainable training concepts that keep knowledge continuously up-to-date and support appropriate antibiotic prescriptions
Adaptable Symbol Table Management by Meta Modeling and Generation of Symbol Table Infrastructures
Many textual software languages share common concepts such as defining and
referencing elements, hierarchical structures constraining the visibility of
names, and allowing for identical names for different element kinds. Symbol
tables are useful to handle those reference and visibility concepts. However,
developing a symbol table can be a tedious task that leads to an additional
effort for the language engineer. This paper presents a symbol table meta model
usable to define languagespecific symbol tables. Furthermore, we integrate this
symbol table meta model with a meta model of a grammar-based language
definition. This enables the language engineer to switch between the model
structure and the symbol table as needed. Finally, based on a grammarannotation
mechanism, our approach is able to generate a symbol table infrastructure that
can be used as is or serve as a basis for custom symbol tables.Comment: 8 pages, 9 figures, Domain-Specific Modeling Workshop 2015 (DSM 2015
CDK12 Inhibition Reverses De Novo and Acquired PARP Inhibitor Resistance in BRCA Wild-Type and Mutated Models of Triple-Negative Breast Cancer
© 2016 The Author(s) Although poly(ADP-ribose) polymerase (PARP) inhibitors are active in homologous recombination (HR)-deficient cancers, their utility is limited by acquired resistance after restoration of HR. Here, we report that dinaciclib, an inhibitor of cyclin-dependent kinases (CDKs) 1, 2, 5, and 9, additionally has potent activity against CDK12, a transcriptional regulator of HR. In BRCA-mutated triple-negative breast cancer (TNBC) cells and patient-derived xenografts (PDXs), dinaciclib ablates restored HR and reverses PARP inhibitor resistance. Additionally, we show that de novo resistance to PARP inhibition in BRCA1-mutated cell lines and a PDX derived from a PARP-inhibitor-naive BRCA1 carrier is mediated by residual HR and is reversed by CDK12 inhibition. Finally, dinaciclib augments the degree of response in a PARP-inhibitor-sensitive model, converting tumor growth inhibition to durable regression. These results highlight the significance of HR disruption as a therapeutic strategy and support the broad use of combined CDK12 and PARP inhibition in TNBC