Hyperactive Rac stimulates cannibalism of living target cells and enhances CAR-M-mediated cancer cell killing (BMDM RNA-seq)
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE247104 | GEO | 2023/11/13
REPOSITORIES: GEO
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Project description:The 21kD GTPase Rac is an evolutionarily ancient regulator of cell shape and behavior. Rac2 is predominantly expressed in hematopoietic cells where it is essential for survival and motility. The hyperactivating mutation Rac2E62K also causes human immunodeficiency, although the mechanism remains unexplained. Here we report that in Drosophila, hyperactivating Rac stimulates ovarian cells to cannibalize neighboring cells, destroying the tissue. We then show that hyperactive Rac2E62K stimulates human HL60-derived macrophage-like cells to engulf and kill living T cell leukemia cells. Primary mouse Rac2E62K/+ bone-marrow-derived macrophages also cannibalize primary Rac2E62K/+ T cells due to a combination of macrophage hyperactivity and T cell hypersensitivity to engulfment. Additionally, Rac2E62K/+ macrophages non-autonomously stimulate wild type macrophages to engulf T cells. Rac2E62K also enhances engulfment of target cancer cells by chimeric antigen receptor-expressing macrophages (CAR-M). We propose that Rac-mediated cell cannibalism may contribute to Rac2E62K/+ human immunodeficiency and enhance CAR-M cancer immunotherapy.
2023-11-13 | GSE247103 | GEO
Project description:Macrophages rapidly engulf apoptotic cells to limit the release of noxious cellular contents and to restrict autoimmune responses against self antigens. Although factors participating in recognition and engulfment of apoptotic cells have been identified, the transcriptional basis for the sensing and silently disposing of apoptotic cells is unknown. Here we show that peroxisome proliferator activated receptor delta (PPARdelta) is induced when macrophages engulf apoptotic cells and functions as a transcriptional sensor of dying cells. Genetic deletion of PPARdelta decreases expression of opsonins, such as C1qb, resulting in impairment of apoptotic cell clearance and reduction in anti-inflammatory cytokine production. This increases autoantibody production and predisposes global and macrophage-specific PPARdelta deficient mice to autoimmune kidney disease, a phenotype resembling the human disease systemic lupus erythematosus. Thus, PPARdelta plays a pivotal role in orchestrating the timely disposal of apoptotic cells by macrophages, ensuring that tolerance to self is maintained. HoxA9 immortalized ES cell derived myeloid precursors were created and differentiated as in Odegaard et al, 2007. After expansion, macrophages were differentiated for 8 days in the presence of MCSF in 20% L929 conditioned media with 2.5% bovine serum albumin in low glucose media. Macrophages were harvested for RNA using Qiagen's RNeasy Kit. A common reference was generated using e17.5 C57Bl/6 embryos. 30ug of either reference or macrophage RNA was labeled with Cy3 and Cy5 (Amersham) and hybridized to Stanford Functional Genomics Facility mouse cDNA microarrays for 16 hours. The arrays were washed and scanned on an Agilent G2505A ChipScan v. A.6.3.1. Florescence values were extracted using GenePix Pro v. 5.0.0.51. The data were normalized using regression correlation. Subsequently, missing values were imputed and significantly differentially expressed genes were found with Significance Analysis of Microarrays. For the Nature Medicine manuscript, significantly differentially expressed genes including genes involved in the process of uptake of apoptotic cells were extracted and clustered by complete linkage using Cluster and visualized using TreeView. Key to genotypes: "J1 untreated" are WT differentiated macrophages; "18 Untreated" are PPARd-/- differentiated macrophages Genotype: Wild type (WT) or PPAR delta minus (PPARd -/-) macrophages genetic_modification_design
2010-06-21 | E-GEOD-17890 | biostudies-arrayexpress
Project description:There are no described quality assurance mechanisms for newly formed stem cells. We observed intimate interactions between macrophages and blood stem cells in zebrafish embryos. Stressed stem cells were marked by surface Calreticulin, which stimulates macrophage interaction as an eat me signal. Macrophage-stem cell interactions either lead to removal of cytoplasmic material and stem cell proliferation or resulted in complete stem cell engulfment. Calreticulin knock down or embryonic macrophage depletion reduced the number of stem cell clones into adulthood. Our work supports a model in which embryonic macrophages determine hematopoietic clonality by monitoring stem cell quality.
2022-02-04 | MSV000088780 | MassIVE
Project description:HACE1 is an E3 ubiquitin ligase with important roles in tumor biology and tissue homeostasis. Loss or mutation of HACE1 has been associated with the occurrence of a variety of neoplasms, but the underlying mechanisms have not been defined yet. Here we report that HACE1 is frequently mutated in human lung cancer. In mice, loss of Hace1 led to enhanced progression of KRasG12D-driven lung tumors. Additional ablation of the oncogenic GTPase Rac1 partially reduced progression of Hace1-/- lung tumors. RAC2, a novel ubiquitylation target of HACE1, could compensate for the absence of its homolog RAC1 in Hace1-deficient, but not in HACE1-sufficient tumors. Accordingly, ablation of both Rac1 and Rac2 fully averted the increased progression of KRasG12D-driven lung tumors in Hace1-/- mice. In lung cancer patients, increased expression of HACE1 correlated with reduced levels of RAC1 and RAC2 and prolonged survival, while elevated expression of RAC1 and RAC2 was associated with poor prognosis. This work defines HACE1 as a crucial regulator of the oncogenic activity of RAC-family GTPases in lung cancer development.
2020-04-27 | GSE149137 | GEO
Project description:Chimeric antigen receptor (CAR)-T cell therapies have shown great success in treating hematologic malignancies. Nonetheless, their therapeutic effect on solid tumors remains to be improved. Recently, macrophages have attracted great attention, given their ability to infiltrate solid tumors, phagocytize tumor cells as well as their immunomodulatory capacities. The first generation of CD3ζ-based CAR-macrophages demonstrated that the CAR could stimulate macrophage phagocytosis in a tumor antigen-dependent way. Here, we genetically engineered induced pluripotent stem cell (iPSC)-derived macrophages (iMACs) with TLR4 intracellular TIR domain-containing CARs against EGFRvIII and GPC3, which yielded markedly enhanced antitumor effect in two different solid tumor models including glioblastoma, and hepatocellular carcinoma in which complete remission was achieved with CAR-iMACs alone or in combination with CD47 antibody. Moreover, the tandem CD3ζ-TIR-CAR, or the “second-generation” design of TIR-based dual signaling CAR, endowed iMACs with both target engulfment/efferocytosis capacity against antigen-expressing solid tumor cells, and potency of antigen-dependent M1 state polarization and M2 state resistance in an NF-κB dependent manner. We also illustrated a surprising mechanism of tumor cell elimination by CAR-induced efferocytosis against tumor cell apoptotic bodies. Taken together, we established the next generation CAR-iMACs equipped with orthogonal phagocytosis and polarization capacity for better antitumor functions in treating solid tumors.
2023-09-29 | GSE214140 | GEO
Project description:Although apoptotic cells (ACs) contain nucleic acids that can be recognized by Toll-like receptors (TLRs), engulfment of ACs does not initiate inflammation in healthy organisms. To better understand this phenomenon, we identified and characterized macrophage populations that continually engulf ACs in several distinct tissues. These macrophages share characteristics compatible with immunologically silent clearance of ACs, including high expression of AC recognition receptors, low expression of TLR9, and reduced TLR responsiveness to nucleic acids. When removed from tissues, these macrophages lose many of these characteristics and generate inflammatory responses to AC-derived nucleic acids, suggesting that cues from the tissue microenvironment are required to program macrophages for silent AC clearance. We show that KLF2 and KLF4 control expression of many genes within this AC clearance program. Coordinated expression of AC receptors with genes that limit responses to nucleic acids may represent a central feature of tissue macrophages that ensures maintenance of homeostasis.
2017-11-15 | GSE93820 | GEO
Project description:Macrophages, play an essential role in promoting tumor growth by affecting angiogenesis, immune suppression, invasion and metastasis. The signal transduction events within macrophages which encode the complex cascade of events required for tumor growth and polarization of macrophages are poorly understood. We have discovered an ECM dependent signaling pathway in macrophages that regulates M2 macrophage differentiation, tumor growth, invasion and metastasis. We provide direct evidence that a macrophage autonomous, M-NM-14M-NM-21 integrin dependent Syk-Rac2 signaling axis acts in concert with the p110 isoform (PTEN-PI-3 kinase pathway) to control metastasis. Bone marrow derived macrophages from five wild type and five Rac2 -/- mutant C57BL mice.
2012-10-02 | E-GEOD-41236 | biostudies-arrayexpress
Project description:Rac GTPases are required for neutrophil adhesion and migration, and for the neutrophil effector responses that kill pathogens. These Rac-dependent functions are impaired when neutrophils lack the activators of Rac, Rac-GEFs from the Prex, Vav and Dock families. In this study, we demonstrate that Tiam1 is also expressed in neutrophils, governing focal complexes, actin cytoskeletal dynamics, polarisation and migration, in a manner depending on the integrin ligand to which the cells adhere. Tiam1 is dispensable for the generation of reactive oxygen species but mediates degranulation and NETs release in adherent neutrophils, as well as the killing of bacteria. In vivo, Tiam1 is required for neutrophil recruitment during aseptic peritonitis and for the clearance of Streptococcus pneumoniae during pulmonary infection. However, Tiam1 functions differently to other Rac-GEFs. Instead of promoting neutrophil adhesion to ICAM1 and stimulating β2 integrin activity as could be expected, Tiam1 restricts these processes. In accordance with these paradoxical inhibitory roles, Tiam1 limits the fMLP-stimulated activation of Rac1 and Rac2 in adherent neutrophils, rather than activating Rac as expected. Tiam1 promotes the expression of several regulators of small GTPases and cytoskeletal dynamics, including αPix, Psd4, Rasa3 and Tiam2. It also controls the association of Rasa3, and potentially αPix, Git2, Psd4 and 14‐3‐3ζ/δ, with Rac. We propose these latter roles of Tiam1 underlie its effects on Rac and β2 integrin activity and on cell responses. Hence, Tiam1 is a novel regulator of Rac-dependent neutrophil responses that functions differently to other known neutrophil Rac-GEFs.
2024-01-26 | PXD046791 | Pride
Project description:Macrophages rapidly engulf apoptotic cells to limit the release of noxious cellular contents and to restrict autoimmune responses against self antigens. Although factors participating in recognition and engulfment of apoptotic cells have been identified, the transcriptional basis for the sensing and silently disposing of apoptotic cells is unknown. Here we show that peroxisome proliferator activated receptor delta (PPARdelta) is induced when macrophages engulf apoptotic cells and functions as a transcriptional sensor of dying cells. Genetic deletion of PPARdelta decreases expression of opsonins, such as C1qb, resulting in impairment of apoptotic cell clearance and reduction in anti-inflammatory cytokine production. This increases autoantibody production and predisposes global and macrophage-specific PPARdelta deficient mice to autoimmune kidney disease, a phenotype resembling the human disease systemic lupus erythematosus. Thus, PPARdelta plays a pivotal role in orchestrating the timely disposal of apoptotic cells by macrophages, ensuring that tolerance to self is maintained. HoxA9 immortalized ES cell derived myeloid precursors were created and differentiated as in Odegaard et al, 2007. After expansion, macrophages were differentiated for 8 days in the presence of MCSF in 20% L929 conditioned media with 2.5% bovine serum albumin in low glucose media. Macrophages were harvested for RNA using Qiagen's RNeasy Kit. A common reference was generated using e17.5 C57Bl/6 embryos. 30ug of either reference or macrophage RNA was labeled with Cy3 and Cy5 (Amersham) and hybridized to Stanford Functional Genomics Facility mouse cDNA microarrays for 16 hours. The arrays were washed and scanned on an Agilent G2505A ChipScan v. A.6.3.1. Florescence values were extracted using GenePix Pro v. 5.0.0.51. The data were normalized using regression correlation. Subsequently, missing values were imputed and significantly differentially expressed genes were found with Significance Analysis of Microarrays. For the Nature Medicine manuscript, significantly differentially expressed genes including genes involved in the process of uptake of apoptotic cells were extracted and clustered by complete linkage using Cluster and visualized using TreeView. Key to genotypes: "J1 untreated" are WT differentiated macrophages; "18 Untreated" are PPARd-/- differentiated macrophages Genotype: Wild type (WT) or PPAR delta minus (PPARd -/-) macrophages
2009-10-18 | GSE17890 | GEO
Project description:Purpose: The ability of MSCs to modulate macrophages is well documented but the mechanism is unknown. The goal of this study was to compare the transcriptome of macrophages that engulf MSCs to those that do not. Methods: Mouse splenocytes were cocultured with Qtracker labelled human cord tissue derived MSC for 3 days. Afterwards, CD11b+Ly6G- macrophages that were either Qtracker positive or negative were FACs sorted for RNA sequencing. Results: We determined that gene involved in antigen presentation and the activation of T cells were differentially expressed in macrophages that engulfed MSCs. Conclusion: Our study suggests that macrophages which engulf components of hCT-MSCs and are subsequently reprogrammed to suppress the activation of T cells, even after hCT-MSCs are no longer present.
2023-05-04 | GSE149848 | GEO