The density of Tbet+ tumor-infiltrating T lymphocytes reflects an effective and druggable preexisting adaptive antitumor immune response in colorectal cancer, irrespective of the microsatellite status

e23087 Background: In colorectal cancer (CRC), little is known about mechanisms by which tumor cells can influence the phenotype and biology of Tumor Infiltrating T lymphocytes (TILs) of the tumor microenvironment. One of these mechanisms could be the inflammasome, a molecular platform present in normal intestinal epithelial cells, whose effector protein, caspase-1, can rapidly mature IL18 and generate a mucosal Th1/Tc1 (IFNγ) response. However, the inflammasome status of tumor cells in CRC and its potential role on TILs are unknown yet. Methods: Prospective and retrospective cohort studies aimed to determine in CRC patients: the status of the inflammasome in tumor cells (IL18 immunostaining on tissue microarrays (TMA) and in situ detection of active caspase-1 on frozen sections) and the density of TILs (CD8+, T-bet+) in relation with i) the microsatellite stable (MSS) or unstable (MSI) status of CRC, and ii) the levels of cytokines (IL18, IFNγ) secreted in an ex vivo explant culture model of CRC. Finally, we assessed the effect of recombinant human IL18 (rhIL18) on the IFNγ response of isolated TILs. Results: TMA analysis of the retrospective cohort showed that IL18 was significantly expressed (in more than 50% of tumor cells) in 80% of CRC, especially in MSI CRC, and correlated with a high density of T-bet+ and CD8+ intraepithelial TILs (IEL-TILs). Active caspase-1 was detected in tumor cells in 60% of CRC. In the prospective cohort, the presence of active caspase-1 in tumor cells was associated with high levels of mature IL18 secreted in explant cultures, with high density of T-bet+ TILs and with IFNγ release in most cases. In addition, isolated TILs expressing IL18 receptors (IL18Rα), cultured with rhIL18, were able to secrete IFNγ either unstimulated or stimulated with OKT3. Conclusions: The inflammasome of tumor cells, when maintained and active, can contribute to a Th1/Tc1 antitumor immune response elicited by TILs, that can modulate tumor growth. The inflammasome of tumor cells can thus be considered as a potential new therapeutic target to strengthen the antitumor immune response in CRC, in association with other immunotherapies.

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Role of the inflammasome of tumor cells in modulating the biology of Tumor Infiltrating T lymphocytes (TILs) in colorectal cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.4_suppl.640 ◽

2017 ◽

Vol 35 (4_suppl) ◽

pp. 640-640

Author(s):

Celine Bossard ◽

Delphine Dansette ◽

Adrien Ouairy ◽

Nicolas Jouand ◽

Romain Oger ◽

...

Keyword(s):

Colorectal Cancer ◽

Immune Response ◽

T Lymphocytes ◽

Tumor Cells ◽

Retrospective Cohort ◽

Ex Vivo ◽

High Density ◽

Antitumor Immune Response ◽

Caspase 1 ◽

Active Caspase

640 Background: In colorectal cancer (CRC), little is known about mechanisms by which tumor cells can influence the phenotype and biology of Tumor Infiltrating T lymphocytes (TILs) of the tumor microenvironment. One of these mechanisms could be the inflammasome, a molecular platform present in normal intestinal epithelial cells, whose effector protein, caspase-1, can rapidly mature IL18 and generate a mucosal Th1/Tc1 (IFNg) response. However, the inflammasome status of tumor cells in CRC and its potential role on TILs are unknown yet. Methods: Prospective and retrospective cohort studies aimed to determine in CRC patients: the status of the inflammasome in tumor cells (IL18 immunostaining on tissue microarrays (TMA) and in situ detection of active caspase-1 on frozen sections) and the density of TILs (CD8+, T-bet+) in relation with the microsatellite stable (MSS) or unstable (MSI) status of CRC, and the levels of cytokines (IL18, IFNg) secreted in an ex vivo explant culture model of CRC. Finally, we assessed the effect of recombinant human IL18 (rhIL18) on the IFNg response of isolated TILs. Results: TMA analysis of the retrospective cohort showed that IL18 was significantly expressed (in more than 50% of tumor cells) in 80% of CRC, especially in MSI CRC, and correlated with a high density of T-bet+ and CD8+ intraepithelial TILs (IEL-TILs). Active caspase-1 was detected in tumor cells in 60% of CRC. In the prospective cohort, the presence of active caspase-1 in tumor cells was associated with high levels of mature IL18 secreted in explant cultures, with high density of T-bet+ TILs and with IFNg release in most cases. In addition, isolated TILs expressing IL18 receptors (IL18Ra), cultured with rhIL18, were able to secrete IFNg either unstimulated or stimulated with OKT3. Conclusions: The inflammasome of tumor cells, when maintained and active, can contribute to a Th1/Tc1 antitumor immune response elicited by TILs, that can modulate tumor growth. The inflammasome of tumor cells can thus be considered as a potential new therapeutic target to strengthen the antitumor immune response in CRC, in association with other immunotherapies.

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Combining PARP inhibition, radiation, and immunotherapy: A possible strategy to improve the treatment of cancer?

International Journal of Molecular Sciences ◽

10.3390/ijms19123793 ◽

2018 ◽

Vol 19 (12) ◽

pp. 3793 ◽

Cited By ~ 20

Author(s):

Mathieu Césaire ◽

Juliette Thariat ◽

Serge M. Candéias ◽

Dinu Stefan ◽

Yannick Saintigny ◽

...

Keyword(s):

Immune Response ◽

Radiation Therapy ◽

T Lymphocytes ◽

Ionizing Radiation ◽

Cytotoxic T Lymphocytes ◽

Tumor Antigens ◽

Checkpoint Inhibitors ◽

Parp Inhibitors ◽

Antitumor Immune Response ◽

Parp Inhibition

Immunotherapy has revolutionized the practice of oncology, improving survival in certain groups of patients with cancer. Immunotherapy can synergize with radiation therapy, increase locoregional control, and have abscopal effects. Combining it with other treatments, such as targeted therapies, is a promising means of improving the efficacy of immunotherapy. Because the value of immunotherapy is amplified with the expression of tumor antigens, coupling poly(ADP-ribose) polymerase (PARP) inhibitors and immunotherapy might be a promising treatment for cancer. Further, PARP inhibitors (PARPis) are being combined with radiation therapy to inhibit DNA repair functions, thus enhancing the effects of radiation; this association might interact with the antitumor immune response. Cytotoxic T lymphocytes are central to the antitumor immune response. PARP inhibitors and ionizing radiation can enhance the infiltration of cytotoxic T lymphocytes into the tumor bed, but they can also enhance PD-1/PDL-1 expression. Thus, the addition of immune checkpoint inhibitors with PARP inhibitors and/or ionizing radiation could counterbalance such immunosuppressive effects. With the present review article, we proposed to evaluate some of these associated therapies, and we explored the biological mechanisms and medical benefits of the potential combination of radiation therapy, immunotherapy, and PARP inhibitors.

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Improvement of immune response after radiofrequency ablation in colorectal cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2018.36.5_suppl.102 ◽

2018 ◽

Vol 36 (5_suppl) ◽

pp. 102-102 ◽

Cited By ~ 2

Author(s):

Katia Lemdani ◽

Nathalie Mignet ◽

Johanne Seguin ◽

Frederique Peschaud ◽

Jean-François Emile ◽

...

Keyword(s):

Colorectal Cancer ◽

Immune Response ◽

Radiofrequency Ablation ◽

T Lymphocytes ◽

Immune Escape ◽

Liver Tumors ◽

Residual Disease ◽

Checkpoint Inhibitors ◽

T Cell Response

102 Background: Radiofrequency ablation (RFA) efficiency of liver tumors is compromised by high rates of relapse. Death of cancer cells by hyperthermia induced tumor antigen releasing, expression of danger signals that activate a specific T-cell response. This effect is ineffective to avoid recurrence. We propose to combine RFA with priming of a strong immune antitumor response as curative treatment of an aggressive colorectal cancer (CRC) in immunocompetent mouse. Methods: RFA was used to treat a CT26- luc tumor as primary lesion. In two distinct clinical situations, macroscopic or microscopic distant tumors were established as secondary lesions. The immune response was modulated by the injection, in the treated area, of a thermo-reversible hydrogel loaded by GM-CSF and BCG, targeting recruitment and maturation of dendritic cells. In mice with far large lesions, this strategy was combined with PD1checkpoint inhibition. The efficiency was assessed on survival, evolution of distant lesions, characterization of tumoral lymphocyte infiltration TNF-α and IFN-y expression in peripheral T lymphocytes. Results: The in situ immunogel injection after RFA resulted in prolonged survival of mice. Regression of distant lesions was related to the induction of a strong systemic antitumor immune response and a great improvement of tumor infiltration by CD3+ T lymphocytes. In adjuvant situation, the use of immunogel induced a complete cure of microscopic secondary lesions without another treatment. Immune escape of large secondary lesions was reversed by association of the RFA-immunogel vaccination with a systemic immune checkpoint inhibition, separately ineffective. Conclusions: Validation of this strategy, combining RFA of macroscopic lesions and activation of a strong immune response controlling the residual disease, could result in the design of a clinical assay including this approach within a standard treatment of colorectal liver metastases. The synergy between in situ immunomodulation as priming process and checkpoint blockade, ineffective alone in metastatic microsatellite stable CRC or after single RFA, allows reconsidering the use of checkpoint inhibitors in CRC.

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Mesenchymal Stem Cells Promote Metastasis of Lung Cancer Cells by Downregulating Systemic Antitumor Immune Response

Stem Cells International ◽

10.1155/2017/6294717 ◽

2017 ◽

Vol 2017 ◽

pp. 1-11 ◽

Cited By ~ 11

Author(s):

Marina Gazdic ◽

Bojana Simovic Markovic ◽

Nemanja Jovicic ◽

Maja Misirkic-Marjanovic ◽

Valentin Djonov ◽

...

Keyword(s):

Nitric Oxide ◽

Lung Cancer ◽

Stem Cells ◽

Immune Response ◽

Mesenchymal Stem Cells ◽

T Lymphocytes ◽

Nk Cells ◽

Cancer Metastasis ◽

Antitumor Immune Response ◽

Lung Cancer Metastasis

Since majority of systemically administered mesenchymal stem cells (MSCs) become entrapped within the lungs, we used metastatic model of lung cancer, induced by intravenous injection of Lewis lung cancer 1 (LLC1) cells, to investigate the molecular mechanisms involved in MSC-mediated modulation of metastasis. MSCs significantly augmented lung cancer metastasis, attenuate concentrations of proinflammatory cytokines (TNF-α, IL-17), and increase levels of immunosuppressive IL-10, nitric oxide, and kynurenine in sera of LLC1-treated mice. MSCs profoundly reduced infiltration of macrophages, TNF-α-producing dendritic cells (DCs), TNF-α-, and IL-17-producing CD4+ T cells but increased IL-10-producing CD4+ T lymphocytes in the lungs of tumor-bearing animals. The total number of lung-infiltrated, cytotoxic FasL, perforin-expressing, TNF-α-, and IL-17-producing CD8+ T lymphocytes, and NKG2D-expressing natural killer (NK) cells was significantly reduced in LLC1 + MSC-treated mice. Cytotoxicity of NK cells was suppressed by MSC-conditioned medium. This phenomenon was abrogated by the inhibitors of inducible nitric oxide synthase (iNOS) and indoleamine 2,3-dioxygenase (IDO), suggesting the importance of iNOS and IDO for MSC-mediated suppression of antitumor cytotoxicity of NK cells. This study provides the evidence that MSCs promote lung cancer metastasis by suppressing antitumor immune response raising concerns regarding safety of MSC-based therapy in patients who have genetic susceptibility for malignant diseases.

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