Targeting myeloid-derived suppressor cells and the PD-1/PD-L1 axis to enhance immunotherapy with anti-CEA designer T cells for the treatment of colorectal liver metastases.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 3079-3079
Author(s):  
Rachel A. Burga ◽  
Mitchell Thorn ◽  
Cang T. Nguyen ◽  
Lauren Licata ◽  
N. Joseph Espat ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Liver Metastases ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Murine Splenocytes ◽  
T Cell Suppression ◽  
Programmed Death ◽  
Cell Suppression

3079 Background: Immunotherapy for colorectal cancer liver metastases (CRCLM) is limited by the intrahepatic immunosuppressive environment mediated in part by myeloid derived suppressor cells (MDSC), which expand in response to tumor. T cell suppression can be mediated by programmed death ligand-1 (PD-L1, CD274) on MDSC binding to programmed death-1 (PD-1, CD279) on T cells. We hypothesize blocking PD-L1 will improve adoptive cellular therapy efficacy for CRCLM through inhibition of MDSC-mediated T cell suppression. Methods: “Designer” T cells (dTc) were produced from activated murine splenocytes transduced with chimeric antigen receptor (CAR) specific for CEA. C57BL/6 mice were injected with CEA+ MC38 tumor cells via spleen, and liver MDSC (CD11b+Gr1+) were purified with immunomagnetic beads after two weeks. MDSC were co-cultured with stimulated dTc with or without in vitro PD-L1 blockade. Results: MDSC expanded 2.4-fold in response to CRCLM, and expressed high levels of PD-L1 (63.8% PD-L1+). PD-L1 was equally expressed on both monocytic (CD11b+Ly6G-Ly6C+) and granulocytic (CD11b+Ly6G+) MDSC subsets (43.6% PD-L1+ and 27.9% PD-L1+, respectively). Expression of related ligand, PD-L2 was found to be negligible in both subsets. The cognate inhibitory receptor, PD-1, was expressed on dTc (23.8% PD-1+) and native T cells (37.3% PD-1+). Increasing endogenous T cell expression of PD-1 significantly correlated with MDSC expansion (r=0.9774, p<0.0001) in response to CRCLM. Co-culture of dTc with MDSC demonstrated the suppressive effect of MDSC on dTc proliferation which was abrogated with in vitro targeting of PD-L1. The percentage of dTc proliferating in the presence of CEA+ tumor decreased from 72.2% to 29.3% (p<0.001) with the addition of MDSC, and immunosuppression was reversed with blockade of PD-L1, which resulted in a 1.6-fold increase in dTc proliferation (p=0.01 ). Conclusions: Liver MDSC expand in the presence of CRCLM and mediate suppression of anti-CEA dTc via PD-L1. Our results indicate that blockade of PD-L1:PD-1 engagement is a viable strategy for enhancing the efficacy of adoptive cell therapy for liver metastases.

scholarly journals Independent mechanisms of T cell-suppression by subpopulations of myeloid-derived suppressor cells (MDSC) in tumor-bearing hosts

2013 ◽  
Vol 1 (Suppl 1) ◽  
pp. P193
Author(s):  
Patrick L Raber ◽  
Paul Thevenot ◽  
Rosa Sierra ◽  
Dorota Wyczechowska ◽  
Maria E Ramirez ◽  
...  
Keyword(s):  
T Cell ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Tumor Bearing ◽  
T Cell Suppression ◽  
Cell Suppression

Myeloid-Derived Suppressor Cells in Multiple Myeloma.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2794-2794
Author(s):  
Els Van Valckenborgh ◽  
Jo Van Ginderachter ◽  
Kiavash Movahedi ◽  
Eline Menu ◽  
Karin Vanderkerken
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
T Cell ◽  
Suppressor Cells ◽  
T Cell Responses ◽  
Myeloid Derived Suppressor Cells ◽  
Cell Responses ◽  
T Cell Suppression ◽  
Cell Suppression

Abstract Abstract 2794 Poster Board II-770 Myeloid-derived suppressor cells (MDSCs) are a heterogeneous mix of myeloid cells in different maturation stages generated in the bone marrow. The role of MDSCs in cancer is to suppress T-cell responses, thereby likely regulating tumor progression. In mice, MDSCs are identified by the expression of the surface markers CD11b and Gr-1. Recently, Ly6G+ granulocytic (PMN-MDSC) and Ly6G− monocytic (MO-MDSC) subsets could be distinguished (Movahedi et al. Blood 2008, 111:4233-44). In multiple myeloma patients, the immune function is impaired and this is caused by an immunologically hostile microenvironment and cellular defects, such as decreased numbers of immune cells, and DC or T-cell dysfunction. However, the role of MDSCs in immune suppression in multiple myeloma is not yet described. In this study, we investigated the immunosuppressive activity and mechanism of MDSC subsets in the syngeneic and immunocompetent 5TMM mouse model (5T2 and 5T33 models). In first instance, CD11b+Ly6G− and CD11b+Ly6G+ lineage-committed myeloid MDSC subsets were detected in 5TMM-diseased bone marrow by flow cytometry. These subsets were purified via MACS from the bone marrow of naïve and 5TMM tumor-bearing mice, and analyzed for T-cell suppressive activity. Hereto, CD8+ TCR-transgenic OT-1 splenocytes were stimulated with ovalbumin protein in the presence of purified MDSC subsets, after which T-cell proliferation was measured via 3H-thymidine incorporation. Both MDSC subsets from 5TMM bone marrow were able to suppress antigen-specific T-cell responses at a higher level compared to purified MDSC subsets from normal bone marrow. On average, Ly6G− MDSCs were more suppressive than Ly6G+ MDSCs. The 5T2MM model has a tumor take of approximately 12 weeks. Three weeks after intravenous inoculation of the tumor cells, the suppressive effect of the myeloid subsets was already observed (while the plasmacytosis in the BM was very low and no detectable serum M spike was observed), indicating that T-cell suppression is an early event in MM development. To unravel the suppressive mechanism of the MDSC subsets, inhibitors were used in ovalbumin-stimulated cocultures. Ly6G− MDSC-mediated suppression was partially reversed by the iNOS inhibitor L-NMMA and the COX-2 inhibitor sc-791, both of which lower the NO concentration in culture. In contrast, superoxide dismutase and especially catalase enhance NO concentrations, resulting in enhanced T-cell suppression. None of these inhibitors had any impact on the Ly6G+ MDSC-mediated suppression. In conclusion, these data reveal the presence of MDSCs as a novel immune suppressive strategy employed by multiple myeloma cells in the bone marrow, already occurring early in the disease process. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Myeloid-derived suppressor cells are bound and inhibited by anti-thymocyte globulin

2019 ◽  
Vol 25 (1) ◽  
pp. 46-59 ◽  
Author(s):  
Young Suk Lee ◽  
Eduardo Davila ◽  
Tianshu Zhang ◽  
Hugh P Milmoe ◽  
Stefanie N Vogel ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Suppressor Cells ◽  
Arginase Activity ◽  
T Cell Proliferation ◽  
Myeloid Derived Suppressor Cells ◽  
Tumor Bearing ◽  
And Function

Myeloid-derived suppressor cells (MDSCs) inhibit T cell responses and are relevant to cancer, autoimmunity and transplant biology. Anti-thymocyte globulin (ATG) is a commonly used T cell depletion agent, yet the effect of ATG on MDSCs has not been investigated. MDSCs were generated in Lewis Lung Carcinoma 1 tumor-bearing mice. MDSC development and function were assessed in vivo and in vitro with and without ATG administration. T cell suppression assays, RT-PCR, flow cytometry and arginase activity assays were used to assess MDSC phenotype and function. MDSCs increased dramatically in tumor-bearing mice and the majority of splenic MDSCs were of the polymorphonuclear subset. MDSCs potently suppressed T cell proliferation. ATG-treated mice developed 50% fewer MDSCs and these MDSCs were significantly less suppressive of T cell proliferation. In vitro, ATG directly bound 99.6% of MDSCs. CCR7, L-selectin and LFA-1 were expressed by both T cells and MDSCs, and binding of LFA-1 was inhibited by ATG pre-treatment. Arg-1 and PD-L1 transcript expression were reduced 30–40% and arginase activity decreased in ATG-pretreated MDSCs. MDSCs were bound and functionally inhibited by ATG. T cells and MDSCs expressed common Ags which were also targets of ATG. ATG may be helpful in tumor models seeking to suppress MDSCs. Alternatively, ATG may inadvertently inhibit important T cell regulatory events in autoimmunity and transplantation.

Monocyte-Derived Dendritic Cells Induce Functionally Active Regulatory T Cells Upon Exposure to BCR-ABL Tyrosine Kinase Inhibitors.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2156-2156
Author(s):  
Michael Gutknecht ◽  
Simone Joas ◽  
Lisa Güttler ◽  
Lothar Kanz ◽  
Helmut R Salih ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitors ◽  
Kinase Inhibitors ◽  
T Cell Suppression ◽  
Cell Suppression

Abstract Abstract 2156 Multiple approaches for treatment of malignant disease presently aim to combine targeted therapy with tyrosine kinase inhibitors (TKI) with immunotherapy. Dendritic cells (DC) are frequently used in such strategies due to their unique ability to initiate potent T cell anti-tumor immunity. Unfortunately, DC may also activate suppressive CD25+FOXP3+ regulatory T cells (Treg), which depends on the stimuli that influence DC in immature state and/or during development from precursor cells. High frequencies of Treg have been described in several types of tumors within the tumor microenvironment, which is associated with poor prognosis and reduced survival. DC development and function are moreover governed by various tyrosine kinases of which some are also inhibited by clinically used TKI. TKI thus may cause immunoinhibitory side effects, and we previously demonstrated that exposure of monocyte-derived DC to the BCR-ABL inhibitor imatinib causes up-regulation of the immunosuppressive type I transmembrane glycoprotein osteoactivin (GPNMB, DC-HIL) and reduces expression of activating surface antigens as well as T cell-stimulatory capacity of DC in vitro (Schwarzbich et al., 2012). Other investigators reported that imatinib induces functionally Treg in CML patients, but the underlying mechanisms are so far unknown. (Bachy et al., 2011). On the other hand, TKI may inhibit proliferation and suppressive capacity of regulatory T cells in vitro (Chen et al., 2007). Here we tried to solve this apparent discrepancy by analyzing the influence of TKI on DC-Treg interaction. Monocyte-derived DC (moDC) were generated over 7 days by exposing blood monocytes to GM-CSF and IL-4. TNF was added on day 6 of culture in case of maturation, and imatinib or nilotinib (3μM each) were added to the culture medium every second day starting from the first day of culture. Induction and functionality of Treg was determined by FACS and so called effector T cell suppression assays upon culture of moDC with autologous PBMC. We found that exposure of moDC to imatinib or nilotinib only slightly increased the frequency of Treg as compared to controls. However, these Treg strongly inhibited autologous T cell proliferation as assessed by T cell suppression assays. This was mediated by direct cellular interaction, as culture supernatants of TKI-treated DC did not alter Treg function and also did not contain elevated levels of the immunosuppressive (and Treg inducing) cytokines TGF-β and IL-10. Thus, our data indicate that the seemingly contradictory results of the in vivo and in vitro studies described above may be explained by the effects caused by exposure of moDC to BCR-ABL TKI which results in the induction of functionally active Treg. These findings are of special importance for future combinatory approaches using TKI and DC-based immunotherapy. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Hepatic Stellate Cells Enhance Liver Cancer Progression by Inducing Myeloid-Derived Suppressor Cells through Interleukin-6 Signaling

2019 ◽  
Vol 20 (20) ◽  
pp. 5079 ◽  
Author(s):  
Ching-Chuan Hsieh ◽  
Chien-Hui Hung ◽  
Meihua Chiang ◽  
Yu-Chin Tsai ◽  
Jie-Teng He
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Hepatic Stellate Cells ◽  
Suppressor Cells ◽  
Stellate Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Term Survival ◽  
Arginase 1

The tumor microenvironment, which consists of fibroblasts, smooth muscle cells, endothelial cells, immune cells, epithelial cells, and extracellular matrices, plays a crucial role in tumor progression. Hepatic stellate cells (HSCs), a class of unique liver stromal cells, participate in immunomodulatory activities by inducing the apoptosis of effector T-cells, generation of regulatory T-cells, and development of myeloid-derived suppressor cells (MDSCs) to achieve long-term survival of islet allografts. This study provides in vitro and in vivo evidences that HSCs induce the generation of MDSCs to promote hepatocellular carcinoma (HCC) progression through interleukin (IL)-6 secretion. HSC-induced MDSCs highly expressed inducible nitric oxide synthase (iNOS) and arginase 1 mRNA and presented potent inhibitory T-cell immune responses in the tumor environment. Wild-type HSC-induced MDSCs expressed lower levels of CD40, CD86, and MHC II, and a higher level of B7-H1 surface molecules, as well as increased the production of iNOS and arginase I compared with MDSCs induced by IL-6-deficient HSCs in vitro. A murine-transplanted model of the liver tumor showed that HCCs cotransplanted with HSCs could significantly enhance the tumor area and detect more MDSCs compared with HCCs alone or HCCs cotransplanted with HSCs lacking IL-6. In conclusion, the results indicated that MDSCs are induced mainly by HSCs through IL-6 signaling and produce inhibitory enzymes to reduce T-cell immunity and then promote HCC progression within the tumor microenvironment. Therapies targeting the pathway involved in MDSC production or its immune-modulating pathways can serve as an alternative immunotherapy for HCC.

Mesenchymal Stem Cells and Fibroblasts Have Similar Immunoregulatory Properties In Vitro but Distinct Gene Expression Profiles: Implications for Cellular Therapy.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1930-1930 ◽  
Author(s):  
Muzlifah A. Haniffa ◽  
Xiao N. Wang ◽  
Udo Holtick ◽  
Daniel C. Swan ◽  
Sarah Bullock ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
T Cells ◽  
Mesenchymal Stem Cells ◽  
T Cell ◽  
Stromal Cells ◽  
Cellular Therapy ◽  
T Cell Suppression ◽  
Cell Suppression

Abstract Bone marrow mesenchymal stem cells (MSC) have potent immunosuppressive properties and are being evaluated in human trials of graft versus host disease (GVHD). The nature of their suppressive capacity is not well understood but attributed to their stem cell function. Evidence that adult stromal cells such as fibroblasts (Fb) also modulate T cell functions has important implications for immunoregulation and cellular therapy. We have investigated the phenomenon of MSC-mediated immunosuppression by comparing MSC with Fb of different origins in in vitro assays of T cell suppression and modulation. We have then isolated RNA from paired samples of dermal Fb and MSC from 6 healthy volunteers for comparative gene expression studies. Adherent Fb were isolated from digested dermis, synovium and lung. MSC were obtained from BM aspirate. Fb from the dermis, lung and synovium possess potent immunomodulatory properties. Fb suppress allogeneic T cell activation by autologously derived cutaneous antigen presenting cells and other stimulators. Fb-mediated suppression through soluble factors is dependent on IFNγ from activated T cells. IFNγ induces indoleamine-2, 3, dioxygenase in Fb with accelerated tryptophan metabolism being partly responsible for suppressing T cell proliferation. T cell suppression is reversible and exposure to stromal cells during activation reprogrammes T cells, increasing secretion of interleukin-4 2.3 fold, interleukin-10 4.3 fold and interleukin-13 15 fold (means of 4 experiments) upon restimulation. Increased Th2 polarization by stromal cells is associated with amelioration of pathological changes in an in vitro human GVHD model. Our findings also show that Fb from different sources are indistinguishable from MSC with respect to morphology, phenotype, growth and differentiation capacity in vitro. Clonogenicity (ratio of CFU to CD73+CD45- cells) of Fb and MSC are similar (range 0.2 to 0.46 CFU/cell) proving that the immunosuppressive effects of Fb from adult tissues are not due to the expansion of rare ‘stem’ cells. Using paired isolates of dermal Fb and MSC to control for inter-individual variation, we were able to define consistent differences in gene expression. Microarray assays were performed using a Human Genome Focus Affymetrix array and analysed with GeneSpring GX. 143 of 9600 probesets showed reproducible differences in transcript levels between dermal Fb and MSC. Probesets upregulated in MSC include genes encoding immunomodulatory mediators: vascular endothelial growth factor (7 fold), hydroxysteroid 17β dehydrogenase (10 fold) and jagged1 (5 fold); extracellular adhesion molecules: proteoglycan1 (264 fold), vascular cell adhesion molecule (175 fold), transglutaminase (67 fold) and procollagen (8 fold); and developmental regulators in the Hedgehog and Wnt signalling pathways. Our findings are further evidence that immunosuppression is a generic property of Fb isolated from several sources and not restricted to MSC. We have for the first time identified a differential expression profile of MSC compared with Fb. These differences may not confer unique in vivo immunosuppressive properties and the potential of Fb as an alternative source of cellular therapy remains untested.

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