Abstract P108: In vivo CRISPR screens identify E3 ligase COP1 as a modulator of macrophage infiltration and cancer immunotherapy target

SUMMARYDespite remarkable clinical efficacies of immune checkpoint blockade (ICB) in cancer treatment, ICB benefits in triple-negative breast cancer (TNBC) remain limited. Through pooled in vivo CRISPR knockout (KO) screens in syngeneic TNBC mouse models, we found that inhibition of the E3 ubiquitin ligase Cop1 in cancer cells decreases the secretion of macrophage-associated chemokines, reduces tumor macrophage infiltration, and shows synergy in anti-tumor immunity with ICB. Transcriptomics, epigenomics, and proteomics analyses revealed Cop1 functions through proteasomal degradation of the C/ebpδ protein. Cop1 substrate Trib2 functions as a scaffold linking Cop1 and C/ebpδ, which leads to polyubiquitination of C/ebpδ. Cop1 inhibition stabilizes C/ebpδ to suppress the expression of macrophage chemoattractant genes. Our integrated approach implicates Cop1 as a target for improving cancer immunotherapy efficacy by regulating chemokine secretion and macrophage levels in the TNBC tumor microenvironment.HighlightsLarge-scale in vivo CRISPR screens identify new immune targets regulating the tumor microenvironmentCop1 knockout in cancer cells enhances anti-tumor immunityCop1 modulates chemokine secretion and macrophage infiltration into tumorsCop1 targets C/ebpδ degradation via Trib2 and influences ICB response

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Pooled in vivo screens for cancer immunotherapy target discovery

Immunotherapy ◽

10.2217/imt-2017-0164 ◽

2018 ◽

Vol 10 (3) ◽

pp. 167-170

Author(s):

Sarah K Lane-Reticker ◽

Robert T Manguso ◽

W Nicholas Haining

Keyword(s):

Cancer Immunotherapy ◽

Target Discovery ◽

Immunotherapy Target

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Faculty Opinions recommendation of In vivo CRISPR screening identifies Ptpn2 as a cancer immunotherapy target.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.727819093.793543387 ◽

2018 ◽

Author(s):

John Lazo

Keyword(s):

Cancer Immunotherapy ◽

Immunotherapy Target

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In vivo CRISPR screening identifies Ptpn2 as a cancer immunotherapy target

Nature ◽

10.1038/nature23270 ◽

2017 ◽

Vol 547 (7664) ◽

pp. 413-418 ◽

Cited By ~ 329

Author(s):

Robert T. Manguso ◽

Hans W. Pope ◽

Margaret D. Zimmer ◽

Flavian D. Brown ◽

Kathleen B. Yates ◽

...

Keyword(s):

Cancer Immunotherapy ◽

Immunotherapy Target

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FOXE1-Dependent Regulation of Macrophage Chemotaxis by Thyroid Cells In Vitro and In Vivo

International Journal of Molecular Sciences ◽

10.3390/ijms22147666 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7666

Author(s):

Sara C. Credendino ◽

Marta De Menna ◽

Irene Cantone ◽

Carmen Moccia ◽

Matteo Esposito ◽

...

Keyword(s):

Thyroid Cancer ◽

Immune Cells ◽

Cancer Susceptibility ◽

Macrophage Infiltration ◽

M2 Macrophage ◽

Thyroid Cells ◽

Transcriptional Alterations ◽

Cancer Phenotypes

Forkhead box E1 (FOXE1) is a lineage-restricted transcription factor involved in thyroid cancer susceptibility. Cancer-associated polymorphisms map in regulatory regions, thus affecting the extent of gene expression. We have recently shown that genetic reduction of FOXE1 dosage modifies multiple thyroid cancer phenotypes. To identify relevant effectors playing roles in thyroid cancer development, here we analyse FOXE1-induced transcriptional alterations in thyroid cells that do not express endogenous FOXE1. Expression of FOXE1 elicits cell migration, while transcriptome analysis reveals that several immune cells-related categories are highly enriched in differentially expressed genes, including several upregulated chemokines involved in macrophage recruitment. Accordingly, FOXE1-expressing cells induce chemotaxis of co-cultured monocytes. We then asked if FOXE1 was able to regulate macrophage infiltration in thyroid cancers in vivo by using a mouse model of cancer, either wild type or with only one functional FOXE1 allele. Expression of the same set of chemokines directly correlates with FOXE1 dosage, and pro-tumourigenic M2 macrophage infiltration is decreased in tumours with reduced FOXE1. These data establish a novel link between FOXE1 and macrophages recruitment in the thyroid cancer microenvironment, highlighting an unsuspected function of this gene in the crosstalk between neoplastic and immune cells that shape tumour development and progression.

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E3 ligase Nedd4l promotes antiviral innate immunity by catalyzing K29-linked cysteine ubiquitination of TRAF3

Nature Communications ◽

10.1038/s41467-021-21456-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Peng Gao ◽

Xianwei Ma ◽

Ming Yuan ◽

Yulan Yi ◽

Guoke Liu ◽

...

Keyword(s):

Posttranslational Modifications ◽

Type I Interferon ◽

Zinc Fingers ◽

E3 Ligase ◽

Type I ◽

E3 Ligases ◽

Protein Posttranslational Modifications ◽

Antiviral Innate Immunity

AbstractUbiquitination is one of the most prevalent protein posttranslational modifications. Here, we show that E3 ligase Nedd4l positively regulates antiviral immunity by catalyzing K29-linked cysteine ubiquitination of TRAF3. Deficiency of Nedd4l significantly impairs type I interferon and proinflammatory cytokine production induced by virus infection both in vitro and in vivo. Nedd4l deficiency inhibits virus-induced ubiquitination of TRAF3, the binding between TRAF3 and TBK1, and subsequent phosphorylation of TBK1 and IRF3. Nedd4l directly interacts with TRAF3 and catalyzes K29-linked ubiquitination of Cys56 and Cys124, two cysteines that constitute zinc fingers, resulting in enhanced association between TRAF3 and E3 ligases, cIAP1/2 and HECTD3, and also increased K48/K63-linked ubiquitination of TRAF3. Mutation of Cys56 and Cys124 diminishes Nedd4l-catalyzed K29-linked ubiquitination, but enhances association between TRAF3 and the E3 ligases, supporting Nedd4l promotes type I interferon production in response to virus by catalyzing ubiquitination of the cysteines in TRAF3.

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