Small Molecule SHIP Agonist AQX-MN100 Inhibits Multiple Myeloma (MM) Cell Growth In NOD/SCID Mice and Reduces Immune Suppressive Myeloid Derived Suppressor Cells (MDSC) and Regulatory T Cells (Tregs) In Mouse Model

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 792-792
Author(s):  
Alice Mui ◽  
Mike Kennah ◽  
Christopher Ong ◽  
Raymond Anderson ◽  
Heather Sutherland
Keyword(s):  
Tumor Volume ◽  
Suppressor Cells ◽  
Pi3k Pathway ◽  
Akt Signaling ◽  
Myeloid Derived Suppressor Cells ◽  
Hemopoietic Cells ◽  
Equity Ownership

Abstract Abstract 792 We recently described a novel anti-MM drug (AQX-MN100) which is a small molecule agonist of SHIP (Src homology-2 (SH2) containing inositol-5¢-phosphatase) a signaling molecule found only in hemopoietic cells.(Ong et al, Blood; 110:1942, 2007) The molecule was developed using a high-throughput SHIP enzyme assay to screen an invertebrate marine natural product library and isolate the Pelorol.(Yang et al Org Lett; 7:1073, 2005) SHIP normally functions to negatively regulate the PI3K pathway important to normal hemopoietic cells growth and function. Inappropriate activation of the phosphoinositide 3- kinase (PI3K) pathway has been shown to be involved in the pathogenesis of MM and tumour aggressiveness correlates with the degree of activation. The critical role the PI3K/Akt signaling pathway plays in regulating MM cell survival, has stimulated efforts in designing therapeutics that target this pathway. Pan PI3K inhibitors have limited utility in a clinical setting because of their inhibitory effects on all isoforms of the PI3K family as well as non-PI3K targets. SHIP is an exceptionally good target for MM and other hematopoietic disorders that display elevated PI3K/Akt signaling because its expression is restricted to hemopoietic cells. We have shown that an analogue of Pelorol, AQX-MN100 is able to inhibit PI3K signaling and prevent phosphorylation of Akt. AQX-MN100 induced MM cell line apoptosis mediated by caspase and was specific for SHIP expressing cells which are exclusively hematopoietic. AQX-MN100 also enhances the growth inhibition effects of current myeloma drugs Dexamethasone and Bortezomib on human MM tumour cell lines in vitro. (Kennah et al Expt Hematol; 37:1274, 2009) In this study we have extended these finding to further evaluate the role of this compound in the treatment of myeloma. NOD-SCID mice were injected in the lateral flanks with 2 million luciferase tagged MM1.S multiple myeloma cells in Matrigel. Tumors were allowed to establish for two weeks and then either AQX-MN100 or vehicle was administered in an oil deposit subcutaneously in the lower flank at a dose of 50 mg/kg every three days. Tumor volume was quantified by imaging on a Xenogen IVIS 200 after 6 and 11 days. These studies demonstrate a significant reduction of tumor volume at 6 days p<0.05 and a highly significant reduction at 11 days p<0.01 in the mice receiving AQX-MN100 as compared to vehicle. We have shown that AQX-MN100 can directly kill MM cells in in vitro and in vivo. However, based on the known functions of SHIP, we predict that SHIP agonists will additionally target critical steps in MM pathogenesis in vivo, including the ability of MM cells to interact with stromal elements and to subvert the immune system. In order to evaluate this later feature we evaluated the ability of SHIP agonists to reverse the tumor associated immune suppression in MM patients. Tumor and host cell/tumor microenvironment secreted factors promote the production and activation of cells associated with cancer progression: the immune suppressive myeloid derived suppressor cells (MDSC) and regulatory T cells (Tregs). These cells normally regulate immune responses by inhibiting the activation of immune effector cells. The involvement of SHIP in the regulation of these cells is predicted by the observation that MDSC and Treg numbers are elevated in SHIP deficient mice. In this study Balb/C mice, 6 mice/group in duplicate were given either AQX-MN100 3 mg/kg and 10 mg/kg or vehicle once daily orally. At the end of three weeks mesenteric lymph nodes were harvested and subjected to FACS analysis to determine the proportion of MDSC (CD11b+Gr1+) and Treg (CD4+CD25+FoxP3+) cells. Spleen cells were also analysed for B cells, NK cells and granulocytes. In both of the AQX-MN100 treated groups the numbers of MDSC and Tregs were significantly lower than controls while Total CD11b, Total CD3, and spleen B, NK and granulocytes were not different from vehicle treated controls. The known role of SHIP in regulating hemopoietic cell function and the role of SHIP agonists in MM cell killing as well as additional actions on other aspects of MM pathophysiology may make them a powerful treatment option for MM, either alone or in synergy with other known MM therapies. Further development of this agent for the treatment of MM is ongoing. Disclosures: Mui: Aquinox: Equity Ownership, Patents & Royalties. Ong:Aquinox: Equity Ownership, Patents & Royalties. Anderson:Aquinox: Equity Ownership, Patents & Royalties. Sutherland:Celgene: Honoraria; Orthobiotech: Honoraria.

scholarly journals Granulocytic myeloid-derived suppressor cells inhibit T follicular helper cells during experimental Schistosoma japonicum infection

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yumei Zhang ◽  
Yulong Wu ◽  
Hua Liu ◽  
Wenci Gong ◽  
Yuan Hu ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Th Cells ◽  
Tfh Cells ◽  
Follicular Helper

Abstract Background CD4+ T helper (Th) cells play critical roles in both host humoral and cellular immunity against parasitic infection and in the immunopathology of schistosomiasis. T follicular helper (Tfh) cells are a specialized subset of Th cells involved in immunity against infectious diseases. However, the role of Tfh cells in schistosome infection is not fully understood. In this study, the dynamics and roles of Tfh cell regulation were examined. We demonstrated that granulocytic myeloid-derived suppressor cells (G-MDSC) can suppress the proliferation of Tfh cells. Methods The levels of Tfh cells and two other Th cells (Th1, Th2) were quantitated at different Schistosoma japonicum infection times (0,3, 5, 8, 13 weeks) using flow cytometry. The proliferation of Tfh cells stimulated by soluble egg antigen (SEA) and soluble worm antigen (SWA) in vivo and in vitro were analyzed. Tfh cells were co-cultured with MDSC to detect the proliferation of Tfh cells labelled by 5(6)-carboxyfluorescein diacetate N-succinimidyl ester. We dynamically monitored the expression of programmed cell death protein 1 (PD-1) on the surface of Tfh cells and programmed cell death ligand 1 (PD-L1) on the surface of MDSC at different infection times (0, 3, 5, 8 weeks). Naïve CD4+ T cells (in Tfh cell differentiation) were co-cultured with G-MDSC or monocytic MDSC in the presence, or in the absence, of PD-L1 blocking antibody. Results The proportion of Tfh cells among CD4+ T cells increased gradually with time of S. japonicum infection, reaching a peak at 8 weeks, after which it decreased gradually. Both SEA and SWA caused an increase in Tfh cells in vitro and in vivo. It was found that MDSC can suppress the proliferation of Tfh cells. The expression of PD-1 on Tfh cells and PD-L1 from MDSC cells increased with prolongation of the infection cycle. G-MDSC might regulate Tfh cells through the PD-1/PD-L1 pathway. Conclusions The reported study not only reveals the dynamics of Tfh cell regulation during S. japonicum infection, but also provides evidence that G-MDSC may regulate Tfh cells by PD-1/PD-L1. This study provides strong evidence for the important role of Tfh cells in the immune response to S. japonicum infection. Graphical abstract

scholarly journals The critical immunosuppressive effect of MDSC-derived exosomes in the tumor microenvironment

2020 ◽  
Author(s):  
Mohammad H. Rashid ◽  
Thaiz F. Borin ◽  
Roxan Ara ◽  
Raziye Piranlioglu ◽  
Bhagelu R. Achyut ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Cd8 T Cells ◽  
Suppressor Cells ◽  
Cell Types ◽  
Biological Macromolecules

AbstractMyeloid-derived suppressor cells (MDSCs) are an indispensable component of the tumor microenvironment (TME), and our perception regarding the role of MDSCs in tumor promotion is attaining extra layer of intricacy in every study. In conjunction with MDSC’s immunosuppressive and anti-tumor immunity, they candidly facilitate tumor growth, differentiation, and metastasis in several ways that yet to be explored. Alike any other cell types, MDSCs also release a tremendous amount of exosomes or nanovesicles of endosomal origin and partake in intercellular communications by dispatching biological macromolecules. There has not been any experimental study done to characterize the role of MDSCs derived exosomes (MDSC exo) in the modulation of TME. In this study, we isolated MDSC exo and demonstrated that they carry a significant amount of proteins that play an indispensable role in tumor growth, invasion, angiogenesis, and immunomodulation. We observed higher yield and more substantial immunosuppressive potential of exosomes isolated from MDSCs in the primary tumor area than those are in the spleen or bone marrow. Our in vitro data suggest that MDSC exo are capable of hyper activating or exhausting CD8 T-cells and induce reactive oxygen species production that elicits activation-induced cell death. We confirmed the depletion of CD8 T-cells in vivo by treating the mice with MDSC exo. We also observed a reduction in pro-inflammatory M1-macrophages in the spleen of those animals. Our results indicate that immunosuppressive and tumor-promoting functions of MDSC are also implemented by MDSC-derived exosomes which would open up a new avenue of MDSC research and MDSC-targeted therapy.

scholarly journals Astaxanthin Treatment Induces Maturation and Functional Change of Myeloid-Derived Suppressor Cells in Tumor-Bearing Mice

Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 350
Author(s):  
Seong Mun Jeong ◽  
Yeon-Jeong Kim
Keyword(s):  
Mhc Class Ii ◽  
Target Genes ◽  
Suppressor Cells ◽  
Functional Change ◽  
Related Factor ◽  
Mrna Levels ◽  
Myeloid Derived Suppressor Cells ◽  
Antitumor Effects

Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells which accumulate in stress conditions such as infection and tumor. Astaxanthin (ATX) is a well-known antioxidant agent and has a little toxicity. It has been reported that ATX treatment induces antitumor effects via regulation of cell signaling pathways, including nuclear factor erythroid-derived 2-related factor 2 (Nrf2) signaling. In the present study, we hypothesized that treatment with ATX might induce maturation of MDSCs and modulate their immunosuppressive activity. Both in vivo and in vitro treatment with ATX resulted in up-regulation of surface markers such as CD80, MHC class II, and CD11c on both polymorphonuclear (PMN)-MDSCs and mononuclear (Mo)-MDSCs. Expression levels of functional mediators involved in immune suppression were significantly reduced, whereas mRNA levels of Nrf2 target genes were increased in ATX-treated MDSCs. In addition, ATX was found to have antioxidant activity reducing reactive oxygen species level in MDSCs. Finally, ATX-treated MDSCs were immunogenic enough to induce cytotoxic T lymphocyte response and contributed to the inhibition of tumor growth. This demonstrates the role of ATX as a regulator of the immunosuppressive tumor environment through induction of differentiation and functional conversion of MDSCs.

scholarly journals Staphylococcus aureus biofilm elicits the expansion, activation and polarization of myeloid-derived suppressor cells in vivo and in vitro

PLoS ONE ◽  
2017 ◽  
Vol 12 (8) ◽  
pp. e0183271 ◽  
Author(s):  
Kuo-Ti Peng ◽  
Ching-Chuan Hsieh ◽  
Tsung-Yu Huang ◽  
Pei-Chun Chen ◽  
Hsin-Nung Shih ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells

scholarly journals IMPACT OF ENDOSTATIN GENE THERAPY ON MYELOID-DERIVED SUPPRESSOR CELLS FROM A METASTATIC RENAL CELL CARCINOMA

2018 ◽  
Vol 40 (1) ◽  
pp. 24-32
Author(s):  
K CB Chaves ◽  
E M Costa ◽  
L F Teixeira ◽  
M H Bellini
Keyword(s):  
Gene Therapy ◽  
Renal Cell Carcinoma ◽  
Flow Cytometry ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Metastatic Progression

Aim: To evaluate the role of endostatin (ES) gene therapy on myeloid-derived suppressor cells (MDSC) in a metastatic model of renal cell carcinoma (RCC). Materials and Methods: Balb/C mice bearing orthotopic Renca tumors were treated with NIH/3T3LendSN or, as a control, with NIH/3T3-LXSN cells. At the end of in vivo experiment, plasma and tissue lung samples were collected. Plasma ES and granulocyte colony stimulating factor (G-CSF) levels were measured by ELISA and Milliplex, respectively. Quantification of CD11b+Gr-1+ cells and their subsets was performed by flow cytometry. Reactive oxygen species (ROS) production was measured in CD11b+Gr-1+ MDSC using the DCFDA marker by flow cytometry. Results: Metastatic RCC (mRCC) induced expansions of CD11b+Gr-1+ MDSC and promoted accumulation of these cells and their subtypes in lymphoid organ and metastases. ES treatment promoted low G-CSF plasmatic levels which were produced by the tumor microenvironment, reflecting the reduced metastatic accumulation of CD11b+Gr-1+ MDSC in the lungs. However, the therapy was selective for granulocytic cells, thus reducing the production of ROS. Conclusion: These findings confirm the expansion of MDSC during metastatic progression of RCC and indicate the important role of ES in reducing MDSC and possible use of ES therapy in combined anticancer treatment.

scholarly journals CD38 Is a Key Regulator of Tumor Growth By Modulating the Metabolic Signature of Malignant Plasma Cells

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2652-2652
Author(s):  
Ruxandra Maria Irimia ◽  
Margo Brooke Gerke ◽  
Maya Thakar ◽  
Zhihong Ren ◽  
Eric Helmenstine ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Cell Lines ◽  
Tumor Volume ◽  
Plasma Cells ◽  
Growth Impairment ◽  
Nsg Mice ◽  
Cd38 Expression

Abstract Introduction: Multiple myeloma (MM) is a disease of malignant plasma cells, characterized by high CD38 expression. Although the CD38-targeting monoclonal antibodies are highly effective, resistance invariably arises. Tumor CD38 levels decrease after anti-CD38 therapy, but the expression is rarely permanently silenced. This suggests that CD38 expression may offer a tumor cell survival advantage, but the direct impact of CD38 loss on tumor dynamics has not been extensively characterized. Methods: CD38 knockout (KO) cell lines were generated by CRISPR-Cas9. Immunocompetent Balb/c and immunodeficient NSG mice were injected subcutaneously with either non-targeting (NT) or CD38 KO J558 cells. Stromal adhesion was compared using labeled NT and KO cells, with OP-9 murine stroma cells. Cellular NAD content was quantified using the Promega Glo Assay. Mitochondria were isolated with the Mitochondria Isolation Kit (Thermo Scientific). Oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) were quantified using the Seahorse Assay. Response to hypoxia was evaluated using a modular hypoxic chamber. Cell cycle was quantified using propidium iodine staining. Results: To examine the role of CD38 in murine models, we utilized the CD38-expressing, murine plasmacytoma cell line J558. Strikingly, CD38 KO cells injected into Balb/c mice demonstrated significantly decreased tumor volume compared to NT (113 mm 3 (KO) vs. 1293 mm 3 (NT) at day 25, p &lt;0.001). In contrast, in vitro cell proliferation and colony formation between KO and NT J558 cells were nearly identical, suggesting that the effects of CD38-loss were highly context dependent. Since tumoral CD38 expression may negatively modulate the immune response, we next compared CD38 KO and NT cells injected into immunodeficient NSG mice. CD38 KOs demonstrated an approximately 2.2-fold decreased tumor volume compared to the NT (708 mm 3 (KO) vs. 1592 mm 3 (NT), p=0.07). Further examination of the role of CD38 on the immune microenvironment are ongoing. Considering that some tumor growth impairment was maintained in immunodeficient mice, we next interrogated the effect of CD38 loss on other aspects of cell proliferation using J558 as well as human MM cell lines RPMI-8226 and NCI-H929. Daratumumab induced CD38 internalization has been shown to reduce stromal adhesion of MM cells. Similarly, CD38 KO cells demonstrated reduced stromal adhesion (2.5-fold decrease for J558, p&lt;0.005 and 2-fold decrease for H929, p&lt;0.005). Although stroma is a known promoter of cell survival and proliferation, we further questioned whether the NAD-metabolizing activity of CD38 modulates tumor growth. CD38 overexpression can drive down intracellular NAD and impair mitochondrial biogenesis. Accordingly, we found significantly higher NAD levels in the KO J558 tumor cells compared to NT (2-fold change, p &lt;0.05). Additionally, CD38 KO cells demonstrated significantly higher levels of mitochondrial protein compared with the NTs (5-fold in J558 and 2-fold in H929). CD38 KO cell lines also showed markedly increased metabolic activity, with nearly 2-fold increase in basal OCR and ECAR, as well as in spare respiratory and glycolytic capacity. Given the contrast between in vivo and in vitro growth capacity, we questioned whether changes in mitochondrial content and metabolic function could confer an advantage for CD38-expressing cells under conditions of hypoxia, which is an important characteristic of the tumor microenvironment. Strikingly, under hypoxia, but not normoxia, CD38 KO MM cells demonstrated significantly more cell cycle arrest, defined by G0/G1 blockage (p=0.003 for H929 and p=0.004 for RPMI). Conclusion: We have shown that CD38 KO cells demonstrate decreased tumor growth in vivo but not in vitro. While the immune modulatory potential of CD38 is recognized, some of the growth impairment we observed may be explained by non-immune mediated mechanisms such as reduced stroma adherence as well as changes in cell metabolism. Loss of CD38 was associated with increased mitochondrial respiration, but also elevated ECAR and glycolytic rate. Higher reliance on mitochondrial respiration could explain impaired CD38 KO proliferation rates under hypoxia, possibly as a result of increased generation of reactive oxygen species. Disclosures Ghiaur: Menarini Richerche: Research Funding; Syros Pharmaceuticals: Consultancy.

scholarly journals Glucosamine Interferes With Myelopoiesis and Enhances the Immunosuppressive Activity of Myeloid-Derived Suppressor Cells

2021 ◽  
Vol 8 ◽  
Author(s):  
Eric Chang-Yi Lin ◽  
Shuoh-Wen Chen ◽  
Luen-Kui Chen ◽  
Ting-An Lin ◽  
Yu-Xuan Wu ◽  
...  
Keyword(s):  
Glucose Transporter ◽  
Immune Cell ◽  
Suppressor Cells ◽  
Therapeutic Benefit ◽  
Myeloid Derived Suppressor Cells ◽  
Hematopoietic Stem ◽  
Glucose Transporter 1 ◽  
Arginase 1

Glucosamine (GlcN) is the most widely consumed dietary supplement and exhibits anti-inflammatory effects. However, the influence of GlcN on immune cell generation and function is largely unclear. In this study, GlcN was delivered into mice to examine its biological function in hematopoiesis. We found that GlcN promoted the production of immature myeloid cells, known as myeloid-derived suppressor cells (MDSCs), both in vivo and in vitro. Additionally, GlcN upregulated the expression of glucose transporter 1 in hematopoietic stem and progenitor cells (HSPCs), influenced HSPC functions, and downregulated key genes involved in myelopoiesis. Furthermore, GlcN increased the expression of arginase 1 and inducible nitric oxide synthase to produce high levels of reactive oxygen species, which was regulated by the STAT3 and ERK1/2 pathways, to increase the immunosuppressive ability of MDSCs. We revealed a novel role for GlcN in myelopoiesis and MDSC activity involving a potential link between GlcN and immune system, as well as the new therapeutic benefit.

scholarly journals IMMU-28. TARGETING IMMUNOSUPPRESSIVE MYELOID DERIVED SUPPRESSOR CELLS VIA MIF/CD74 SIGNALING AXIS TO ATTENUATE GBM GROWTH

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi125-vi125
Author(s):  
Tyler Alban ◽  
Defne Bayik ◽  
Balint Otvos ◽  
Matthew Grabowski ◽  
Manmeet Ahluwalia ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Immune Cell ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Signaling Axis ◽  
Immunosuppressive Microenvironment ◽  
And Function

Abstract The immunosuppressive microenvironment in glioblastoma (GBM) enables persistent tumor growth and evasion from tumoricidal immune cell recognition. Despite a large accumulation of immune cells in the GBM microenvironment, tumor growth continues, and evidence for potent immunosuppression via myeloid derived suppressor cells (MDSCs) is now emerging. In agreement with these observations, we have recently established that increased MDSCs over time correlates with poor prognosis in GBM, making these cells of interest for therapeutic targeting. In seeking to reduce MDSCs in GBM, we previously identified the cytokine macrophage migration inhibitory factor (MIF) as a possible activator of MDSC function in GBM. Here, using a novel in vitro co-culture system to reproducibly and rapidly create GBM-educated MDSCs, we observed that MIF was essential in the generation of MDSCs and that MDSCs generated via this approach express a repertoire of MIF receptors. CD74 was the primary MIF receptor in monocytic MDSCs (M-MDSC), which penetrate the tumor microenvironment in preclinical models and patient samples. A screen of MIF/CD74 interaction inhibitors revealed that MN-166, a clinically relevant blood brain barrier penetrant drug, which is currently fast tracked for FDA approval, reduced MDSC generation and function in vitro. This effect was specific to M-MDSC subsets expressing CD74, and appeared as reduced downstream pERK signaling and MCP-1 secretion. In vivo, MN-166 was able reduce tumor-infiltrating MDSCs, while conferring a significant increase in survival in the syngeneic glioma model GL261. These data provide proof of concept that M-MDSCs can be targeted in the tumor microenvironment via MN-166 to reduce tumor growth and provide a rationale for future clinical assessment of MN-166 to reduce M-MDSCs in the tumor microenvironment. Ongoing studies are assessing the effects of MDSC inhibition in combination with immune activating approaches, in order to inhibit immune suppression while simultaneously activating the immune system.

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