IN VIVO EVIDENCE: THE ROLE OF COMPLEMENT COMPONENT 3 (C3) IN INDUCTION OF MYELOID-DERIVED SUPPRESSOR CELLS (MDSC)

2010 ◽  
Vol 90 ◽  
pp. 237
Author(s):  
H. S. Chou ◽  
H. Yang ◽  
C. Hsieh ◽  
L. Wang ◽  
J. J. Fung ◽  
...  

Blood ◽  
2013 ◽  
Vol 121 (10) ◽  
pp. 1760-1768 ◽  
Author(s):  
Ching-Chuan Hsieh ◽  
Hong-Shiue Chou ◽  
Horng-Ren Yang ◽  
Feng Lin ◽  
Sumantha Bhatt ◽  
...  

Key Points C3 and MDSC development



2018 ◽  
Vol 40 (1) ◽  
pp. 24-32
Author(s):  
K CB Chaves ◽  
E M Costa ◽  
L F Teixeira ◽  
M H Bellini

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.



Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 792-792
Author(s):  
Alice Mui ◽  
Mike Kennah ◽  
Christopher Ong ◽  
Raymond Anderson ◽  
Heather Sutherland

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.



Author(s):  
Saeed Kolahian ◽  
Negar Nowroozi Larki ◽  
Hasan Halit Öz ◽  
Carolin Schroth ◽  
Amir Ali Shahbazfar ◽  
...  


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yumei Zhang ◽  
Yulong Wu ◽  
Hua Liu ◽  
Wenci Gong ◽  
Yuan Hu ◽  
...  

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



Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 726
Author(s):  
Christopher Groth ◽  
Ludovica Arpinati ◽  
Merav E. Shaul ◽  
Nina Winkler ◽  
Klara Diester ◽  
...  

Background: Despite recent improvement in the treatment of malignant melanoma by immune-checkpoint inhibitors, the disease can progress due to an immunosuppressive tumor microenvironment (TME) mainly represented by myeloid-derived suppressor cells (MDSC). However, the relative contribution of the polymorphonuclear (PMN) and monocytic (M) MDSC subsets to melanoma progression is not clear. Here, we compared both subsets regarding their immunosuppressive capacity and recruitment mechanisms. Furthermore, we inhibited PMN-MDSC migration in vivo to determine its effect on tumor progression. Methods: Using the RET transgenic melanoma mouse model, we investigated the immunosuppressive function of MDSC subsets and chemokine receptor expression on these cells. The effect of CXCR2 inhibition on PMN-MDSC migration and tumor progression was studied in RET transgenic mice and in C57BL/6 mice after surgical resection of primary melanomas. Results: Immunosuppressive capacity of intratumoral M- and PMN-MDSC was comparable in melanoma bearing mice. Anti-CXCR2 therapy prolonged survival of these mice and decreased the occurrence of distant metastasis. Furthermore, this therapy reduced the infiltration of melanoma lesions and pre-metastatic sites with PMN-MDSC that was associated with the accumulation of natural killer (NK) cells. Conclusions: We provide evidence for the tumor−promoting properties of PMN-MDSC as well as for the anti-tumor effects upon their targeting in melanoma bearing mice.



2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A536-A536
Author(s):  
Juan Dong ◽  
Cassandra Gilmore ◽  
Hieu Ta ◽  
Keman Zhang ◽  
Sarah Stone ◽  
...  

BackgroundV-domain immunoglobulin suppressor of T cell activation (VISTA) is a B7 family inhibitory immune checkpoint protein and is highly expressed on myeloid cells and T cells.1 VISTA acts as both an inhibitory ligand when expressed on antigen-presenting cells and a receptor when expressed on T cells. Our recent study has shown that VISTA is a myeloid cell-specific immune checkpoint and that blocking VISTA can reprogram suppressive myeloid cells and promote a T cell-stimulatory tumor microenvironment.2 In this study, we further demonstrate that VISTA blockade directly alters the differentiation and the suppressive function of myeloid-derived suppressor cells (MDSC).MethodsFlow cytometry was performed to examine VISTA expression on MDSCs in multiple murine tumor models including the B16BL6 melanoma model, MC38 colon cancer model, and the KPC pancreatic cancer models. To examine the role of VISTA in controlling the differentiation and suppressive function of MDSCs, we cultured wild type (WT) and VISTA.KO bone marrow progenitor cells with GM-CSF and IL-6 to induce BM -derived MDSCs.ResultsOur preliminary results show that VISTA is highly expressed on M-MDSCs in B16BL6, MC38 and KPC tumors. In BM-derived MDSCs, VISTA deletion significantly altered the signaling pathways and the differentiation of MDSCs. Multiple inflammatory signaling pathways were downregulated in VISTA KO MDSCs, resulting in decreased production of cytokines such as IL1 and chemokines such as CCL2/4/9, as well as significantly impaired their ability to suppress the activation of CD8+ T cells. The loss of suppressive function in VISTA KO MDSCs is correlated with significantly reduced expression of iNOS. To validate the results from BM-MDSCs, we sorted CD11b+CD11c-Ly6C+Ly6G- M-MDSCs and CD11b+CD11c-Ly6G+ G-MDSCs from B16BL6 tumor tissues and tested the ability of a VISTA-blocking mAb to reverse the suppressive effects of tumor-derived MDSCs. Our results show that blocking VISTA impaired the suppressive function of tumor-derived M-MDSC but not G-MDSCs.ConclusionsTaken together, these results demonstrate a crucial role of VISTA in regulating the differentiation and function of MDSCs, and that blocking VISTA abolishes MDSC-mediated T cell suppression, thereby boosting.Ethics ApprovalAll in vivo studies were reviewed and approved by Institutional Animal Care and Use Committee (Approval number 2019-2142).ReferencesXu W, Hire T, Malarkannan, S. et al. The structure, expression, and multifaceted role of immune-checkpoint protein VISTA as a critical regulator of anti-tumor immunity, autoimmunity, and inflammation. Cell Mol Immunol 2018;15:438–446.Xu W, Dong J, Zheng Y, et al. Immune-checkpoint protein VISTA regulates antitumor immunity by controlling myeloid cell-mediated inflammation and immunosuppression. Cancer Immunol Res 2019;7:1497–510.



Vaccines ◽  
2016 ◽  
Vol 4 (4) ◽  
pp. 36 ◽  
Author(s):  
Viktor Umansky ◽  
Carolin Blattner ◽  
Christoffer Gebhardt ◽  
Jochen Utikal


Author(s):  
Mohammad H. Rashid ◽  
Thaiz F. Borin ◽  
Roxan Ara ◽  
Raziye Piranlioglu ◽  
Bhagelu R. Achyut ◽  
...  

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.



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