Peripheral Innate Lymphoid Cells Are Increased in First Line Metastatic Colorectal Carcinoma Patients: A Negative Correlation With Th1 Immune Responses

Several distinct innate lymphoid cell (ILC) populations have been recently identified and shown to play a critical role in the immediate immune defense. In the context of tumors, there is evidence to support a dual role for ILCs with pro-or antitumor effects, depending on the ILC subset and the type of cancer. This ambivalent role has been particularly well-described in colorectal cancer models (CRC), but the presence and the evolution of ILCs in the peripheral blood of metastatic CRC (mCRC) patients have not yet been explored. Here, we investigated the distribution of ILC subsets in 96 mCRC patients who were prospectively included in the "Epitopes-CRCO2" trial. Peripheral bloodmononuclear cells (PBMCs) were analyzed by flow cytometry at metastatic diagnosis and after 3-months of treatment. The treatments consisted of Oxaliplatin-based chemotherapies for 76% of the patients or Folfiri (5FU, Irinotecan) chemotherapies for 14% of patients. Compared to healthy donors, the frequency of total ILCs was dramatically increased at metastatic diagnosis. CD56(+) ILC1-like cells were expanded, whereas ILC2, NCR- ILCP and NCR+ ILCP subsets were decreased. Combined analysis with the systemic anti-telomerase hTERT Th1 CD4 response revealed that patients with low anti-TERT Th1 CD4 responses had the highest frequencies of total ILCs at diagnosis. Of those, 91% had synchronous metastases, and their median progression-free survival was 7.43 months (vs. 9.17 months for the other patients). In these patients, ILC1 and ILC2 were significantly decreased, whereas CD56(+) ILC1-like cells were significantly increased compared to patients with low frequency of total ILCs and high anti-TERT responses. After treatment, the NCR+ ILCP were further decreased irrespective of the chemotherapy regimen, whereas the balance between ILC1 and CD56(+) ILC1-like cells was modulated mainly by the Folfiri regimen in favor of ILC1. Altogether our results describe the effects of different chemotherapies on ILCs in mCRC patients. We also establish for the first time a link between frequency of ILCs and anti-tumor CD4 T cell responses in cancer patients. Thus, our study supports an interest in monitoring ILCs during cancer therapy to possibly identify predictive biomarkers in mCRC

Two Distinct Pathways Leading to Nuclear Apoptosis

Apaf-1−/− or caspase-3−/− cells treated with a variety of apoptosis inducers manifest apoptosis-associated alterations including the translocation of apoptosis-inducing factor (AIF) from mitochondria to nuclei, large scale DNA fragmentation, and initial chromatin condensation (stage I). However, when compared with normal control cells, Apaf-1−/− or caspase-3−/− cells fail to exhibit oligonucleosomal chromatin digestion and a more advanced pattern of chromatin condensation (stage II). Microinjection of such cells with recombinant AIF only causes peripheral chromatin condensation (stage I), whereas microinjection with activated caspase-3 or its downstream target caspase-activated DNAse (CAD) causes a more pronounced type of chromatin condensation (stage II). Similarly, when added to purified HeLa nuclei, AIF causes stage I chromatin condensation and large-scale DNA fragmentation, whereas CAD induces stage II chromatin condensation and oligonucleosomal DNA degradation. Furthermore, in a cell-free system, concomitant neutralization of AIF and CAD is required to suppress the nuclear DNA loss caused by cytoplasmic extracts from apoptotic wild-type cells. In contrast, AIF depletion alone suffices to suppress the nuclear DNA loss contained in extracts from apoptotic Apaf-1−/− or caspase-3−/− cells. As a result, at least two redundant parallel pathways may lead to chromatin processing during apoptosis. One of these pathways involves Apaf-1 and caspases, as well as CAD, and leads to oligonucleosomal DNA fragmentation and advanced chromatin condensation. The other pathway, which is caspase-independent, involves AIF and leads to large-scale DNA fragmentation and peripheral chromatin condensation

Mitochondrial Release of Caspase-2 and -9 during the Apoptotic Process

The barrier function of mitochondrial membranes is perturbed early during the apoptotic process. Here we show that the mitochondria contain a caspase-like enzymatic activity cleaving the caspase substrate Z-VAD.afc, in addition to three biological activities previously suggested to participate in the apoptotic process: (a) cytochrome c; (b) an apoptosis-inducing factor (AIF) which causes isolated nuclei to undergo apoptosis in vitro; and (c) a DNAse activity. All of these factors, which are biochemically distinct, are released upon opening of the permeability transition (PT) pore in a coordinate, Bcl-2–inhibitable fashion. Caspase inhibitors fully neutralize the Z-VAD.afc–cleaving activity, have a limited effect on the AIF activity, and have no effect at all on the DNase activities. Purification of proteins reacting with the biotinylated caspase substrate Z-VAD, immunodetection, and immunodepletion experiments reveal the presence of procaspase-2 and -9 in mitochondria. Upon induction of PT pore opening, these procaspases are released from purified mitochondria and become activated. Similarly, upon induction of apoptosis, both procaspases redistribute from the mitochondrion to the cytosol and are processed to generate enzymatically active caspases. This redistribution is inhibited by Bcl-2. Recombinant caspase-2 and -9 suffice to provoke full-blown apoptosis upon microinjection into cells. Altogether, these data suggest that caspase-2 and -9 zymogens are essentially localized in mitochondria and that the disruption of the outer mitochondrial membrane occurring early during apoptosis may be critical for their subcellular redistribution and activation

Anticancer chemotherapy and radiotherapy trigger both non-cell-autonomous and cell-autonomous death.

Even though cell death modalities elicited by anticancer chemotherapy and radiotherapy have been extensively studied, the ability of anticancer treatments to induce non-cell-autonomous death has never been investigated. By means of multispectral imaging flow-cytometry-based technology, we analyzed the lethal fate of cancer cells that were treated with conventional anticancer agents and co-cultured with untreated cells, observing that anticancer agents can simultaneously trigger cell-autonomous and non-cell-autonomous death in treated and untreated cells. After ionizing radiation, oxaliplatin, or cisplatin treatment, fractions of treated cancer cell populations were eliminated through cell-autonomous death mechanisms, while other fractions of the treated cancer cells engulfed and killed neighboring cells through non-cell-autonomous processes, including cellular cannibalism. Under conditions of treatment with paclitaxel, non-cell-autonomous and cell-autonomous death were both detected in the treated cell population, while untreated neighboring cells exhibited features of apoptotic demise. The transcriptional activity of p53 tumor-suppressor protein contributed to the execution of cell-autonomous death, yet failed to affect the non-cell-autonomous death by cannibalism for the majority of tested anticancer agents, indicating that the induction of non-cell-autonomous death can occur under conditions in which cell-autonomous death was impaired. Altogether, these results reveal that chemotherapy and radiotherapy can induce both non-cell-autonomous and cell-autonomous death of cancer cells, highlighting the heterogeneity of cell death responses to anticancer treatments and the unsuspected potential contribution of non-cell-autonomous death to the global effects of anticancer treatment

Chemokine receptor patterns in lymphocytes mirror metastatic spreading in melanoma

30siopenMelanoma prognosis is dictated by tumor-infiltrating lymphocytes, the migratory and functional behavior of which is guided by chemokine or cytokine gradients. Here, we retrospectively analyzed the expression patterns of 9 homing receptors (CCR/CXCR) in naive and memory CD4(+) and CD8(+) T lymphocytes in 57 patients with metastatic melanoma (MMel) with various sites of metastases to evaluate whether T cell CCR/CXCR expression correlates with intratumoral accumulation, metastatic progression, and/or overall survival (OS). Homing receptor expression on lymphocytes strongly correlated with MMel dissemination. Loss of CCR6 or CXCR3, but not cutaneous lymphocyte antigen (CLA), on circulating T cell subsets was associated with skin or lymph node metastases, loss of CXCR4, CXCR5, and CCR9 corresponded with lung involvement, and a rise in CCR10 or CD103 was associated with widespread dissemination. High frequencies of CD8(+)CCR9(+) naive T cells correlated with prolonged OS, while neutralizing the CCR9/CCL25 axis in mice stimulated tumor progression. The expansion of CLA-expressing effector memory CD8(+) T cells in response to a single administration of CTLA4 blockade predicted disease control at 3 months in 47 patients with MMel. Thus, specific CCR/CXCR expression patterns on circulating T lymphocytes may guide potential diagnostic and therapeutic approaches.openJacquelot N.; Enot D.P.; Flament C.; Vimond N.; Blattner C.; Pitt J.M.; Yamazaki T.; Roberti M.P.; Daillere R.; Vetizou M.; Poirier-Colame V.; Semeraro M.; Caignard A.; Slingluff C.L.; Sallusto F.; Rusakiewicz S.; Weide B.; Marabelle A.; Kohrt H.; Dalle S.; Cavalcanti A.; Kroemer G.; DI Giacomo A.M.; Maio M.; Wong P.; Yuan J.; Wolchok J.; Umansky V.; Eggermont A.; Zitvogel L.Jacquelot, N.; Enot, D. P.; Flament, C.; Vimond, N.; Blattner, C.; Pitt, J. M.; Yamazaki, T.; Roberti, M. P.; Daillere, R.; Vetizou, M.; Poirier-Colame, V.; Semeraro, M.; Caignard, A.; Slingluff, C. L.; Sallusto, F.; Rusakiewicz, S.; Weide, B.; Marabelle, A.; Kohrt, H.; Dalle, S.; Cavalcanti, A.; Kroemer, G.; DI Giacomo, A. M.; Maio, M.; Wong, P.; Yuan, J.; Wolchok, J.; Umansky, V.; Eggermont, A.; Zitvogel, L

Extracellular ATP acts on P2Y2 purinergic receptors to facilitate HIV-1 infection

Contact with HIV-1 envelope protein elicits release of ATP through pannexin-1 channels on target cells; by activating purinergic receptors and Pyk2 kinase in target cells, this extracellular ATP boosts HIV-1 infectivity

Prognostic impact of vitamin B6 metabolism in lung cancer

Patients with non-small cell lung cancer (NSCLC) are routinely treated with cytotoxic agents such as cisplatin. Through a genome-wide siRNA-based screen, we identified vitamin B6 metabolism as a central regulator of cisplatin responses in vitro and in vivo. By aggravating a bioenergetic catastrophe that involves the depletion of intracellular glutathione, vitamin B6 exacerbates cisplatin-mediated DNA damage, thus sensitizing a large panel of cancer cell lines to apoptosis. Moreover, vitamin B6 sensitizes cancer cells to apoptosis induction by distinct types of physical and chemical stress, including multiple chemotherapeutics. This effect requires pyridoxal kinase (PDXK), the enzyme that generates the bioactive form of vitamin B6. In line with a general role of vitamin B6 in stress responses, low PDXK expression levels were found to be associated with poor disease outcome in two independent cohorts of patients with NSCLC. These results indicate that PDXK expression levels constitute a biomarker for risk stratification among patients with NSCLC.publishedVersio

Beth Levine in memoriam

Beth Levine was born on 7 April 1960 in Newark, New Jersey. She went to college at Brown University where she received an A.B. Magna Cum Laude, and she attended medical school at Cornell University Medical College, receiving her MD in 1986. She completed her internship and residency in Internal Medicine at Mount Sinai Hospital in New York, and her fellowship in Infectious Diseases at The Johns Hopkins Hospital. Most recently, Beth was a Professor of Internal Medicine and Microbiology, Director of the Center for Autophagy Research, and holder of the Charles Sprague Distinguished Chair in Biomedical Science at the University of Texas Southwestern Medical Center in Dallas. Beth died on 15 June 2020 from cancer. Beth is survived by her husband, Milton Packer, and their two children, Rachel (26 years old) and Ben (25 years old). Dr. Levine was as an international leader in the field of autophagy research. Her laboratory identified the mammalian autophagy gene BECN1/beclin 1; identified conserved mechanisms underlying the regulation of autophagy (e.g. BCL2-BECN1 complex formation, insulin-like signaling, EGFR, ERBB2/HER2 and AKT1-mediated BECN1 phosphosphorylation); and provided the first evidence that autophagy genes are important in antiviral host defense, tumor suppression, lifespan extension, apoptotic corpse clearance, metazoan development, Na,K-ATPase-regulated cell death, and the beneficial metabolic effects of exercise. She developed a potent autophagy-inducing cell permeable peptide, Tat-beclin 1, which has potential therapeutic applications in a range of diseases. She was a founding Associate Editor of the journal Autophagy and an editorial board member of Cell and Cell Host & Microbe. She has received numerous awards/honors in recognition of her scientific achievement, including: The American Cancer Society Junior Faculty Research Award (1994); election into the American Society of Clinical Investigation (2000); the Ellison Medical Foundation Senior Scholars Award in Global Infectious Diseases (2004); elected member, American Association of Physicians (2005); appointment as a Howard Hughes Medical Institute Investigator (2008); Edith and Peter O’Donnell Award in Medicine (2008); elected fellow, American Association for the Advancement of Science (2012); election into the National Academy of Sciences (2013); election into the Academy of Medicine, Engineering and Science of Texas (2013); the ASCI Stanley J. Korsmeyer Award (2014); Phyllis T. Bodel Women in Medicine Award, Yale University School of Medicine (2018); recipient, Barcroft Medal, Queen’s University Belfast (2018).Fil: An, Zhenyi. No especifíca;Fil: Ballabi, Andrea. No especifíca;Fil: Bennett, Lynda. 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No especifíca;Fil: Melino, Gerry. No especifíca;Fil: Mizushima, Noboru. No especifíca;Fil: Murphy, Leon O.. No especifíca;Fil: Nixon, Ralph. No especifíca;Fil: Orvedahl, Anthony. No especifíca;Fil: Pattingre, Sophie. No especifíca;Fil: Piacentini, Mauro. No especifíca;Fil: Reggiori, Fulvio. No especifíca;Fil: Ross, Theodora. No especifíca;Fil: Rubinsztein, David C.. No especifíca;Fil: Ryan, Kevin. No especifíca;Fil: Sadoshima, Junichi. No especifíca;Fil: Schreiber, Stuart L.. No especifíca;Fil: Scott, Frederick. No especifíca;Fil: Sebti, Salwa. No especifíca;Fil: Shiloh, Michael. No especifíca;Fil: Shoji, Sanae. No especifíca;Fil: Simonsen, Anne. No especifíca;Fil: Smith, Haley. No especifíca;Fil: Sumpter, Kathryn M.. No especifíca;Fil: Thompson, Craig B.. No especifíca;Fil: Thorburn, Andrew. No especifíca;Fil: Thumm, Michael. No especifíca;Fil: Tooze, Sharon. No especifíca;Fil: Vaccaro, Maria Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Virgin, Herbert W.. No especifíca;Fil: Wang, Fei. No especifíca;Fil: White, Eileen. No especifíca;Fil: Xavier, Ramnik J.. No especifíca;Fil: Yoshimori, Tamotsu. No especifíca;Fil: Yuan, Junying. No especifíca;Fil: Yue, Zhenyu. No especifíca;Fil: Zhong, Qing. No especifíca