Gene Expression Signature and Pro-Angiogenic Function of Tie2-Expressing Macrophages

Chronic inflammation and activation of angiogenesis sustain tumor progression. Recent data indicate that tumor-infiltrating myeloid cells support tumor angiogenesis by regulating multiple pro-angiogenic pathways. However, the functional heterogeneity of myeloid cells - macrophages in particular - may be greater than currently appreciated, and the relative contribution of distinct myeloid cell types to tumor angiogenesis is currently poorly known. Our laboratory identified a subset of tumor-associated macrophages (TAMs) that are required for tumor angiogenesis - the Tie2-expressing macrophages (TEMs). TEMs appear pre-committed to a pro-angiogenic function already when they circulate as monocytes and their elimination from tumor-bearing mice blunts tumor angiogenesis without affecting the recruitment of other myeloid subsets to the tumors. Yet, both the molecular bases of TEMs pro-angiogenic activity and the functional role of the TIE2 receptor in TEM biology are currently unknown. To investigate the molecular identity of TEMs, I developed protocols to purify TEMs and TIE2-TAMs from tumors and compared the gene expression profile of these 2 tumor macrophage subsets. I found that the TEM gene signature is consistent with enhanced pro-angiogenic and tissue-remodelling activity. From such analyses, novel surface markers were established that easily and unambiguously identify TEMs in tumors. Furthermore, I found that circulating Ly6C-monocytes and tumor-infiltrating TEMs express similar gene signatures, suggesting possible developmental relationships between the two myeloid subsets. TEMs, but not other tumor-infiltrating myeloid cells, express the angiopoietin receptor TIE2. To study the functional role of TIE2 in TEMs, I developed a novel lentiviral vector-based, conditional gene knock down platform. Remarkably, Tie2 knock-down in TEMs significantly inhibited angiogenesis and microvascular perfusion in a spontaneous tumor model, recapitulating several features of TEM elimination. In conclusion, these studies provided a molecular characterization of TEMs and related myeloid cells and identified TIE2 as a critical regulator of their proangiogenic function in tumors

Cancer stem cell-derived extracellular vesicles preferentially target MHC-II–macrophages and PD1+ T cells in the tumor microenvironment

Cèl·lules mare del càncer; Càncers de cap i coll; MacròfagsCancer stem cells; Head and neck cancers; MacrophagesCélulas madre del cáncer; Cánceres de cabeza y cuello; MacrófagosImmunotherapy is an approved treatment option for head and neck squamous cell carcinoma (HNSCC). However, the response rate to immune checkpoint blockade is only 13% for recurrent HNSCC, highlighting the urgent need to better understand tumor-immune interplay, with the ultimate goal of improving patient outcomes. HNSCC present high local recurrence rates and therapy resistance that can be attributed to the presence of cancer stem cells (CSC) within tumors. CSC exhibit singular properties that enable them to avoid immune detection and eradication. How CSC communicate with immune cells and which immune cell types are preferentially found within the CSC niche are still open questions. Here, we used genetic approaches to specifically label CSC-derived extracellular vesicles (EVs) and to perform Sortase-mediated in vivo proximity labeling of CSC niche cells. We identified specific immune cell subsets that were selectively targeted by EVCSC and that were found in the CSC niche. Native EVCSC preferentially targeted MHC-II–macrophages and PD1+ T cells in the tumor microenvironment, which were the same immune cell subsets enriched within the CSC niche. These observations indicate that the use of genetic technologies able to track EVs without in vitro isolation are a valuable tool to unveil the biology of native EVCSC.European Molecular Biology Organization (EMBO):Patricia Gonzalez-Callejo short-term fellowship; V Foundation for Cancer Research (VFCR):Natalie M Claudio,Ferdinando Pucci 2019-012

PHD2 regulates arteriogenic macrophages through TIE2 signalling

Peer reviewe

A distinguishing gene signature shared by tumor-infiltrating Tie2-expressing monocytes, blood "resident" monocytes, and embryonic macrophages suggests common functions and developmental relationships

We previously showed that Tie2-expressing monocytes (TEMs) have nonredundant proangiogenic activity in tumors. Here, we compared the gene expression profile of tumor-infiltrating TEMs with that of tumor-associated macrophages (TAMs), spleen-derived Gr1(+)Cd11b(+) neutrophils/myeloid-derived suppressor cells, circulating "inflammatory" and "resident" monocytes, and tumor-derived endothelial cells (ECs) by quantitative polymerase chain reaction-based gene arrays. TEMs sharply differed from ECs and Gr1(+)Cd11b(+) cells but were highly related to TAMs. Nevertheless, several genes were differentially expressed between TEMs and TAMs, highlighting a TEM signature consistent with enhanced proangiogenic/tissue-remodeling activity and lower proinflammatory activity. We validated these findings in models of oncogenesis and transgenic mice expressing a microRNA-regulated Tie2-GFP reporter. Remarkably, resident monocytes and TEMs on one hand, and inflammatory monocytes and TAMs on the other hand, expressed coordinated gene expression profiles, suggesting that the 2 blood monocyte subsets are committed to distinct extravascular fates in the tumor microenvironment. We further showed that a prominent proportion of embryonic/fetal macrophages, which participate in tissue morphogenesis, expressed distinguishing TEM genes. It is tempting to speculate that Tie2(+) embryonic/fetal macrophages, resident blood monocytes, and tumor-infiltrating TEMs represent distinct developmental stages of a TEM lineage committed to execute physiologic proangiogenic and tissue-remodeling programs, which can be co-opted by tumors

Bimodal CD40/Fas-Dependent Crosstalk between iNKT Cells and Tumor-Associated Macrophages Impairs Prostate Cancer Progression

Heterotypic cellular and molecular interactions in the tumor microenvironment (TME) control cancer progression. Here, we show that CD1d-restricted invariant natural killer (iNKT) cells control prostate cancer (PCa) progression by sculpting the TME. In a mouse PCa model, iNKT cells restrained the proangiogenic and immunosuppressive capabilities of tumor-infiltrating immune cells by reducing proangiogenic TIE2+, M2-like macrophages (TEMs), and sustaining pro-inflammatory M1-like macrophages. iNKT cells directly contacted macrophages in the PCa stroma, and iNKT cell transfer into tumorbearing mice abated TEMs, delaying tumor progression. iNKT cells modulated macrophages through the cooperative engagement of CD1d, Fas, and CD40, which promoted selective killing of M2-like and survival of M1-like macrophages. Human PCa aggressiveness associate with reduced intra-tumoral iNKT cells, increased TEMs, and expression of pro-angiogenic genes, underscoring the clinical significance of this crosstalk. Therefore, iNKT cells may control PCa through mechanisms involving differential macrophage modulation, which may be harnessed for therapeutically reprogramming the TME

Immunogenic Chemotherapy Sensitizes Tumors to Checkpoint Blockade Therapy

Checkpoint blockade immunotherapies can be extraordinarily effective, but might benefit only the minority of patients whose tumors are pre-infiltrated by T cells. Here, using lung adenocarcinoma mouse models, including genetic models, we show that autochthonous tumors that lacked T cell infiltration and resisted current treatment options could be successfully sensitized to host antitumor T cell immunity when appropriately selected immunogenic drugs (e.g., oxaliplatin combined with cyclophosphamide for treatment against tumors expressing oncogenic Kras and lacking Trp53) were used. The antitumor response was triggered by direct drug actions on tumor cells, relied on innate immune sensing through toll-like receptor 4 signaling, and ultimately depended on CD8 + T cell antitumor immunity. Furthermore, instigating tumor infiltration by T cells sensitized tumors to checkpoint inhibition and controlled cancer durably. These findings indicate that the proportion of cancers responding to checkpoint therapy can be feasibly and substantially expanded by combining checkpoint blockade with immunogenic drugs

Two- and Three-Dimensional Reconstruction and Analysis of the Straw Tubes Tomography in the Btev Experiment

A check of the eccentricity of the aluminised kapton straw tubes used in the BTeV experiment is accomplished using X-ray tomography of the section of tubes modules. 2 and 3-dimensional images of the single tubes and of the modules are reconstructed and analysed. Preliminary results show that a precision better than 40 $\mu$m can be reached on the measurement of the straw radii.Comment: Presented by F.Massa at ICATPP05, Villa Olmo (Como) Italy, November 2005. 4 pages, 8 figures, uses lnfprep.st

FcRgamma activation regulates inflammation-associated squamous carcinogenesis

Chronically activated leukocytes recruited to premalignant tissues functionally contribute to cancer development; however, mechanisms underlying pro- versus anti-tumor programming of neoplastic tissues by immune cells remain obscure. Using the K14-HPV16 mouse model of squamous carcinogenesis, we report that B cells and humoral immunity foster cancer development by activating Fcgamma receptors (FcgammaRs) on resident and recruited myeloid cells. Stromal accumulation of autoantibodies in premalignant skin, through their interaction with activating FcgammaRs, regulate recruitment, composition, and bioeffector functions of leukocytes in neoplastic tissue, which in turn promote neoplastic progression and subsequent carcinoma development. These findings support a model in which B cells, humoral immunity, and activating FcgammaRs are required for establishing chronic inflammatory programs that promote de novo carcinogenesis

Gas analysis and monitoring systems for the RPC detector of CMS at LHC

1-9, arXiv:physics/0701014. Publisher: Los AlamosNational Laboratoty, CODEN: LNPHF9 available at http://arxiv.org/PS_cache/physics/pdf/0701/0701014v1.pd

Proposal for a systematic study of the CERN Closed Loop gas system used by the RPC muon detectors in CMS

http://www.lnf.infn.it/sis/preprint/pdf/getfile.php?filename=LNF-06-27(IR).pd