Dataset Information

Genetic screen in myeloid cells identifies TNF-? autocrine secretion as a factor increasing MDSC suppressive activity via Nos2 up-regulation.

ABSTRACT: The suppressive microenvironment of tumors remains one of the limiting factors for immunotherapies. In tumors, the function of effector T cells can be inhibited by cancer cells as well as myeloid cells including tumor associated macrophages and myeloid-derived suppressor cells (MDSC). A better understanding of how myeloid cells inhibit T cell function will guide the design of therapeutic strategies to increase anti-tumor responses. We have previously reported the in vitro differentiation of MDSC from immortalized mouse hematopoietic progenitors and characterized the impact of retinoic acid and 3-deazaneplanocin A on MDSC development and function. We describe here the effect of these compounds on MDSC transcriptome and identify genes and pathway affected by the treatment. In order to accelerate the investigation of gene function in MDSC suppressive activity, we developed protocols for CRISPR/Cas9-mediated gene editing in MDSC. Through screening of 217 genes, we found that autocrine secretion of TNF-? contributes to MDSC immunosuppressive activity through up-regulation of Nos2. The approach described here affords the investigation of gene function in myeloid cells such as MDSC with unprecedented ease and throughput.

SUBMITTER: Schroder M

PROVIDER: S-EPMC6128861 | biostudies-other | 2018 Sep

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Genetic screen in myeloid cells identifies TNF-α autocrine secretion as a factor increasing MDSC suppressive activity via Nos2 up-regulation.

Schröder Matthias M Krötschel Marit M Conrad Lena L Naumann Svenja Kerstin SK Bachran Christopher C Rolfe Alex A Umansky Viktor V Helming Laura L Swee Lee Kim LK

Scientific reports 20180907 1

The suppressive microenvironment of tumors remains one of the limiting factors for immunotherapies. In tumors, the function of effector T cells can be inhibited by cancer cells as well as myeloid cells including tumor associated macrophages and myeloid-derived suppressor cells (MDSC). A better understanding of how myeloid cells inhibit T cell function will guide the design of therapeutic strategies to increase anti-tumor responses. We have previously reported the in vitro differentiation of MDSC ...[more]

PMID: 30194424

Similar Datasets

Project description:Mice with hepatocyte-specific deletion of autophagy-related 7 (Atg7 ΔHep mice) develop hepatoma, suggesting that autophagy deficiency could be a factor in the initiation of tumorigenesis. We have shown that FGF21 is induced as a 'mitokine' when Atg7 is disrupted in insulin target tissues such as the liver, which could affect systemic metabolism through endocrine activity. Since FGF21 or other endocrine FGF such as FGF19 can affect tumor growth, we hypothesized that FGF21 produced by Atg7-knockout (KO) hepatocytes may affect the behavior of Atg7-KO hepatoma in an autocrine manner. We, thus, crossed Atg7 ΔHep mice with systemic Fgf21-KO (Fgf21 -/-) mice to generate Atg7 ΔHep Fgf21 -/- mice. The number and size of hepatoma of Atg7 ΔHep mice were significantly increased by additional Fgf21 KO. The proliferation of Atg7-KO hepatocyte was significantly increased by Fgf21 KO. pYAP1/YAP1 representing YAP1 degradation was significantly decreased in the liver of Atg7 ΔHep Fgf21 -/- mice compared to Atg7 ΔHep Fgf21 +/+ mice. Consistently, expression of YAP1/TAZ downstream genes was significantly increased in the liver of Atg7 ΔHep Fgf21 -/- mice compared to Atg7 ΔHep Fgf21 +/+ mice, which could explain the increased size of hepatoma in Atg7 ΔHep Fgf21 -/- mice. Accumulation of ROS and ROS-mediated DNA damage were increased in the liver of Atg7 ΔHep Fgf21 +/+ mice, which was further aggravated by additional Fgf21 KO probably due to the absence of positive effect of FGF21 on mitochondrial function, explaining the increased number of hepatoma in Atg7 ΔHep Fgf21 -/- mice compared to Atg7 ΔHep Fgf21 +/+ mice. These results show that FGF21 produced by autophagy-deficient hepatocytes could have autocrine or paracrine effects on the number and proliferation of autophagy-deficient hepatoma, suggesting that hormones or factors released from autophagy-deficient tumors can influence the behavior or prognosis of the tumor in addition to the effects on host metabolism.

Project description:ObjectivesGlucose-stimulated insulin secretion is a critical function in the regulation of glucose homeostasis, and its deregulation is associated with the development of type 2 diabetes. Here, we performed a genetic screen using islets isolated from the BXD panel of advanced recombinant inbred (RI) lines of mice to search for novel regulators of insulin production and secretion.MethodsPancreatic islets were isolated from 36 RI BXD lines and insulin secretion was measured following exposure to 2.8 or 16.7 mM glucose with or without exendin-4. Islets from the same RI lines were used for RNA extraction and transcript profiling. Quantitative trait loci (QTL) mapping was performed for each secretion condition and combined with transcriptome data to prioritize candidate regulatory genes within the identified QTL regions. Functional studies were performed by mRNA silencing or overexpression in MIN6B1 cells and by studying mice and islets with beta-cell-specific gene inactivation.ResultsInsulin secretion under the 16.7 mM glucose plus exendin-4 condition was mapped significantly to a chromosome 2 QTL. Within this QTL, RNA-Seq data prioritized Crat (carnitine O-acetyl transferase) as a strong candidate regulator of the insulin secretion trait. Silencing Crat expression in MIN6B1 cells reduced insulin content and insulin secretion by ?30%. Conversely, Crat overexpression enhanced insulin content and secretion by ?30%. When islets from mice with beta-cell-specific Crat inactivation were exposed to high glucose, they displayed a 30% reduction of insulin content as compared to control islets. We further showed that decreased Crat expression in both MIN6B1 cells and pancreatic islets reduced the oxygen consumption rate in a glucose concentration-dependent manner.ConclusionsWe identified Crat as a regulator of insulin secretion whose action is mediated by an effect on total cellular insulin content; this effect also depends on the genetic background of the RI mouse lines. These data also show that in the presence of the stimulatory conditions used the insulin secretion rate is directly related to the insulin content.

Dataset Information

Genetic screen in myeloid cells identifies TNF-? autocrine secretion as a factor increasing MDSC suppressive activity via Nos2 up-regulation.

Publications

Genetic screen in myeloid cells identifies TNF-α autocrine secretion as a factor increasing MDSC suppressive activity via Nos2 up-regulation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets