Dataset Information

ER stress sensor PERK drives tumor-promoting myelopoiesis by reprogramming hematopoietic progenitor cells in the spleen

ABSTRACT: The spleen, as the prominent site for extramedullary myelopoiesis in cancer, generates significant amounts of myeloid cells to promote tumor progression. Cancer-associated splenic myelopoiesis is mediated by a population of functionally distinct hematopoietic stem/progenitor cells (HSPCs) that are committed to immunosuppressive myeloid cell generation, but the molecular mechanism regulating this response remains unclear. Here, we found that HSPCs in the spleen of tumor-bearing mice exhibited accelerated protein synthesis and engaged in a robust endoplasmic reticulum (ER) stress response. Single-cell RNA sequencing showed that the ER stress response was concomitant with the myeloid-biased lineage commitment and dysfunction of HSPCs in the spleen. PKR-like ER resident kinase (PERK), a molecular sensor of ER stress, directed HSPC differentiation into myeloid-derived suppressor cells (MDSCs) via PERK–eIF2α–ATF4–C/EBPβ signaling. Inhibition of this signaling prevented the emergence of granulocyte/macrophage colony-stimulating factor-expressing HSPCs in the spleen and disrupted the positive feedback-driven splenic myelopoiesis. Consequently, a blockade of PERK abated the suppressive function of tumor-infiltrating MDSCs and increased cytotoxic T cell infiltration, reshaping the tumor microenvironment to effectively suppress disease progression and potentiate both immuno- and targeted therapies. In accordance, activation of PERK–ATF4–C/EBPβ signaling was indispensable for the differentiation of human umbilical cord blood-derived HSPCs into functionally competent MDSCs. Together, these results indicate a crucial role for the cellular ER stress sensor PERK in modulating splenic HSPC activities in cancer, suggesting novel therapeutic opportunities for targeting the tumor-promoting myeloid response at its source. Raw data are available on Genome Sequence Archive, Bioproject accession number: PRJCA003519

ORGANISM(S): Mus musculus

PROVIDER: GSE158486 | GEO | 2022/03/04

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Tumor growth is associated with a profound alteration of myelopoiesis, leading to recruitment of immunosuppressive cells known as myeloid-derived suppressor cells (MDSCs). Analyzing the cytokines affecting myelo-monocytic differentiation produced by various experimental tumors, we found that GM-CSF, G-CSF, and IL-6 allowed a rapid generation of MDSCs from precursors present in mouse and human bone marrow (BM). BM-MDSCs induced by GM-CSF+IL-6 possessed the highest tolerogenic activity, as revealed by the ability to impair the priming of IFN- -producing CD8+ T cells upon in vivo adoptive transfer. Moreover, adoptive transfer of syngeneic, GM-CSF+IL-6-conditioned MDSCs to diabetic mice transplanted with allogeneic pancreatic islets resulted in long term acceptance of the allograft and correction of the diabetic status. Cytokines inducing MDSCs acted on a common molecular pathway. Immunoregulatory activity of both tumor-induced and BM-derived MDSCs was entirely dependent on C/EBP transcription factor, a key component of the emergency myelopoiesis triggered by stress and inflammation. Adoptive transfer of tumor antigen-specific CD8+ T lymphocytes resulted in therapy of established tumors only in mice lacking C/EBP in myeloid compartment. These data unveil another link between inflammation and cancer and identify a novel molecular target to control tumor-induced immune suppression. We used gene expression analysis to identify those factors, secreted by tumor-infiltrating MDSC, which could drive emathopoiesis. Moreover we compare gene expression profile of tumor-induced MDSC, obtained from either the spleen and the tumor infiltrate of tumor bearing mice, and in vitro bone marrow-derived MDSC. CD11b+ cells were immunomagnetically enriched from various murine tissue and experimental conditions, and cRNA samples were prepared accordingly to Expression Analysis: Technical Manual. 701021 Rev. 5. Santa Clara, CA, Affymetrix; 2004, and hybridized to the Affymetrix GeneChip MOE430 2.0 array which contains more than 45,000 probe sets, representing more than 34,000 genes. CD11b+ cells obtained from the spleen of healthy BALB/c and C57BL/6 mice were used as reference sample for tumor induced CD11b+ MDSC, enriched from either the spleen and the tumor infiltrate of tumor-bearing mice. Moreover CD11b+ cells enriched from fresh bone marrow were used as reference sample for in vitro bone marrow-differentiated MDSC, obtained with either GM-CSF+IL-6 and GM-CSF+G-CSF 4 days cytokine cocktail treatment.

Project description:The gene expression of murine splenic myeloid derived suppressor cells treated with Tff2 is characterized. The motivation of the study originates in the fact that Gr1+Cd11b+ myeloid-derived suppressor cells (MDSCs), which resemble immature myeloid cells (IMCs), expand during cancer in response to inflammatory cytokines and accumulate in the spleen. MDSCs promote neoplastic progression through their suppression of anti-tumourigenic cytotoxic T-cells. MDSCs are also rapidly expanded following acute insults, but in cancer as opposed to acute inflammation, MDSCs persist. It is now recognized that a vagally-mediated, anti-inflammatory reflex arc promoting acetylcholine secretion by Cd4+ (Cd44hiSelllo) T cells, is necessary for a return to homeostasis after an acute insult. Failure of this restorative neural circuit might contribute to unabated procarcinogenic inflammation, with the chronic expansion of MDSCs driving carcinogenesis. Trefoil factor 2 (Tff2) is a secreted anti-inflammatory peptide produced by both epithelial cells and a small subset of splenic T cell. In this study, we show that splenic Tff2 is induced in vagally-modulated memory T cells to suppress the expansion of MDSCs in response to chemical and carcinogenic injury. Deletion of Tff2 interrupts this anti-inflammatory neural arc and leads to expanded MDSCs and a dramatically increased incidence of colorectal cancer. Tff2 directly suppresses proliferation of myeloid progenitors, in a large part through upregulation of cell-bound Apolipoprotein E (ApoE), which has previously been shown to suppress proliferation of haematopoietic stem and progenitor cells. The predisposition to inflammation-associated cancer can be rescued through transgenic overexpression of splenic Tff2, adenoviral transfer of Tff2 expression or transplantation of Tff2-expressing haematopoietic cells. Thus, Tff2 production in memory T cells, is regulated by the vagus nerve, plays a central role in arresting procarcinogenic MDSC proliferation, and offers a novel approach to the prevention and treatment. A. Gr1+Cd11b+ splenic cells from Tff2-/- mice treated with Csf2 (n=4). B. Gr1+Cd11b+ splenic cells from Tff2-/- mice treated with Tff2 and Csf2 (n=4).

Project description:Aging results in enhanced myelopoiesis, which is associated with an increased prevalence of myeloid leukemias and the production of myeloid-derived suppressor cells (MDSCs). Tristetraprolin (TTP) is an RNA binding protein that regulates immune-related cytokines and chemokines by destabilizing target mRNAs. As TTP expression is known to decrease with age in myeloid cells, we used TTP-deficient (TTPKO) mice to model aged mice to study TTP regulation in age-related myelopoiesis. Both TTPKO and myeloidspecific TTPKO (cTTPKO) mice had significant increases in both MDSC subpopulations M-MDSCs (CD11b+Ly6ChiLy6G-) and PMN-MDSCs (CD11b+Ly6CloLy6G+), as well as macrophages (CD11b+F4/80+) in the spleen and mesenteric lymph nodes; however, no quantitative changes in MDSCs were observed in the bone marrow. In contrast, gain-of-function TTP knock-in (TTPKI) mice had no change in MDSCs compared with control mice. Within the bone marrow, total granulocyte-monocyte progenitors (GMPs) and monocyte progenitors (MPs), direct antecedents of M-MDSCs, were significantly increased in both cTTPKO and TTPKO mice, but granulocyte progenitors (GPs) were significantly increased only in TTPKO mice. Transcriptomic analysis of the bone marrow myeloid cell populations revealed that the expression of CC chemokine receptor 2 (CCR2), which plays a key role in monocyte mobilization to inflammatory sites, was dramatically increased in both cTTPKO and TTPKO mice. Concurrently, the concentration of CC chemokine ligand 2 (CCL2), a major ligand of CCR2, was high in the serum of cTTPKO and TTPKO mice, suggesting that TTP impacts the mobilization of M-MDSCs from the bone marrow to inflammatory sites during aging via regulation of the CCR2-CCL2 axis. Collectively, these studies demonstrate a previously unrecognized role for TTP in regulating age-associated myelopoiesis through the expansion of specific myeloid progenitors and M-MDSCs and their recruitment to sites of injury, inflammation, or other pathologic perturbations.

Dataset Information

ER stress sensor PERK drives tumor-promoting myelopoiesis by reprogramming hematopoietic progenitor cells in the spleen

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure