scholarly journals Sorafenib enhances the antitumor effects of anti-CTLA-4 antibody in a murine cancer model by inhibiting myeloid-derived suppressor cells

2015 ◽  
Vol 33 (6) ◽  
pp. 2947-2953 ◽  
Author(s):  
TAKANOBU MOTOSHIMA ◽  
YOSHIHIRO KOMOHARA ◽  
HASITA HORLAD ◽  
ARIO TAKEUCHI ◽  
YOSHIHIRO MAEDA ◽  
...  
Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 350
Author(s):  
Seong Mun Jeong ◽  
Yeon-Jeong Kim

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.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1012-1012
Author(s):  
Parvin Forghani ◽  
Edmund K Waller

Abstract Introduction: Myeloid differentiation primary response gene 88 (Myd 88) is an important adaptor molecule for the activation of NADPH oxidase and regulation of arginase-1, which are responsible for the suppressive function of myeloid-derived suppressor cells (MDSCs). Blockade of Myd88 signaling induces antitumor effects in mice by skewing the immunosuppressive function of myeloid-derived suppressor cells. As the PD-L1/PD-1 axis has been characterized as a potent inhibitor of immune activation, particularly through inhibition of effector T cell function, we characterized the effect of Myd88 on checkpoint expression on tumor-infiltrating MDSC/T cells in a murine model melanoma. Methods: Pathogen-free 8-10-week-old WT(B6-background) and Myd 88−/− mice that been backcrossed to a C57BL/6 genetic background were challenged with 1 × 106 B16 (F1) tumor cells s.c. On day 14, mice were sacrificed and spleen and tumors were removed and digested into single-cell suspensions, blocked with anti-FcR mAbs and analyzed for surface and intracellular staining by flow cytometry. We analyzed CD11b+/Gr-1+hi/int myeloid cells subsets and T cells in the blood, spleen and tumors of mice by flow cytomery. Results: The growth of B16 melanoma tumor was significantly slower in Myd 88−/− mice compared with WT mice. No significant difference between two groups was found in the frequency of absolute number of MDSC subsets and expression of PDL1 check-point marker on spleen-derived MDSC subsets. In contrast CD4(+) and C8(+) T cells residing in spleens of Myd88(-/-) mice showed increased expression of TNF-α/IFN-α and GrZB compared with T cells from wild-type mice following short-term activation with PMA/iono. Of note, the frequencies and absolute numbers of infiltrating CD11b+/Gr1+ MDSC in tumor-bearing Myd 88−/− mice were lower than those in WT mice. Also we found that viable CD11b+/Gr1+ MDSC subsets from WT mice expressed higher level of PD-L1 compared with MDSCs from Myd 88−/− mice in concordance with the reduced expression of PD-1 on tumor infiltrating CD4+ T cells in Myd 88−/− mice. Collectively, the profile of PD-L1 and PD-1 expression in tumor microenvironments is favorably altered to enhance adaptive immune response in myd 88 KO vs WT mice harboring B16 melanoma. Conclusion: The results of this study provide further evidence that blocking Myd 88 signaling increases anti tumor immunity against melanoma, and that the enhanced immunity can be explained, in part, by reduction of expression PDL1/PD1 immune checkpoint molecules. Considering the importance of tumor-infiltrating MDSCs in regulating anti tumor immunity in the tumor microenvironment, our findings could provide insight into the design of new therapeutics targeting Myd 88. Further experiments are needed to show how alteration in profile of PDL1 checkpoint expression on MDSCs influences anti-tumor T cell responses. Disclosures No relevant conflicts of interest to declare.


Author(s):  
Takuma Hayashi ◽  
Kaoru Abiko ◽  
Takuma Hayashi ◽  
Ken Yamaguchi ◽  
Masaki Mandai ◽  
...  

Diagnosis by biopsy is difficult in the ovary, since it is located deep in the abdomen. As a result, ovarian cancer is mostly found insidiously during exploratory laparotomy. Consequently, early diagnosis of ovarian cancer is often difficult. The likelihood of peritoneal dissemination increases with the progress of ovarian cancer. With further progression, ovarian cancer metastasizes to the omentum, retroperitoneal lymph nodes, large intestine, small intestine, diaphragm, spleen, and other organs. Ovarian cancer has been considered a tumor that has a favourable response to chemotherapy, but more effective treatments are still being explored. Tumors use their own immune escape mechanism to evade host immunity. The immune checkpoint (IC) mechanism, one of the immune escape mechanisms, is established by programmed cell death-1 (PD-1)/PDligand-1 (PD-L1) communication. It has been shown that inhibiting PD-1/PD-L1 communication in various malignancies produces antitumor effects. However, the antitumor effect of ICI monotherapy on ovarian cancer is limited in actual clinical practice. In this review, we describe a novel cancer immunotherapeutic agent that targets myeloid-derived suppressor cells (MDSCs).


PLoS ONE ◽  
2014 ◽  
Vol 9 (7) ◽  
pp. e103562 ◽  
Author(s):  
Tae Heung Kang ◽  
Jayne Knoff ◽  
Wei-Hsi Yeh ◽  
Benjamin Yang ◽  
Chenguang Wang ◽  
...  

2016 ◽  
Vol 213 (5) ◽  
pp. 827-840 ◽  
Author(s):  
Lucia D’Amico ◽  
Sahil Mahajan ◽  
Aude-Hélène Capietto ◽  
Zhengfeng Yang ◽  
Ali Zamani ◽  
...  

Tumor–stroma interactions contribute to tumorigenesis. Tumor cells can educate the stroma at primary and distant sites to facilitate the recruitment of heterogeneous populations of immature myeloid cells, known as myeloid-derived suppressor cells (MDSCs). MDSCs suppress T cell responses and promote tumor proliferation. One outstanding question is how the local and distant stroma modulate MDSCs during tumor progression. Down-regulation of β-catenin is critical for MDSC accumulation and immune suppressive functions in mice and humans. Here, we demonstrate that stroma-derived Dickkopf-1 (Dkk1) targets β-catenin in MDSCs, thus exerting immune suppressive effects during tumor progression. Mice bearing extraskeletal tumors show significantly elevated levels of Dkk1 in bone microenvironment relative to tumor site. Strikingly, Dkk1 neutralization decreases tumor growth and MDSC numbers by rescuing β-catenin in these cells and restores T cell recruitment at the tumor site. Recombinant Dkk1 suppresses β-catenin target genes in MDSCs from mice and humans and anti-Dkk1 loses its antitumor effects in mice lacking β-catenin in myeloid cells or after depletion of MDSCs, demonstrating that Dkk1 directly targets MDSCs. Furthermore, we find a correlation between CD15+ myeloid cells and Dkk1 in pancreatic cancer patients. We establish a novel immunomodulatory role for Dkk1 in regulating tumor-induced immune suppression via targeting β-catenin in MDSCs.


2020 ◽  
Vol 8 (1) ◽  
pp. e000478 ◽  
Author(s):  
Thomas Pilot ◽  
Aurélie Fratti ◽  
Chloé Thinselin ◽  
Anaïs Perrichet ◽  
Lucie Demontoux ◽  
...  

BackgroundWe have previously shown that 5-fluorouracil (5-FU) selectively kills myeloid-derived suppressor cells (MDSCs) and activates NLRP3 (NOD-leucine rich repeat and pyrin containing protein 3) inflammasome. NLRP3 activation leads to caspase-1 activation and production of IL-1β, which in turn favors secondary tumor growth. We decided to explore the effects of either a heat shock (HS) or the deficiency in heat shock protein (HSP) 70, previously shown to respectively inhibit or increase NLRP3 inflammasome activation in macrophages.MethodsCaspase-1 activation was detected in vitro in MSC-2 cells by western blot and in vivo or ex vivo in tumor and/or splenic MDSCs by flow cytometry. The effects of HS, HSP70 deficiency and anakinra (an IL-1 inhibitor) on tumor growth and mice survival were studied in C57BL/6 WT orHsp70−/−tumor-bearing mice. Finally, Th17 polarization was evaluated by qPCR (Il17a, Rorc) and angiogenic markers by qPCR (Pecam1, Eng) and immunohistochemistry (ERG).ResultsHS inhibits 5-FU-mediated caspase-1 activation in vitro and in vivo without affecting its cytotoxicity on MDSCs. Moreover, it enhances the antitumor effect of 5-FU treatment and favors mice survival. Interestingly, it is associated to a decreased Th17 and angiogenesis markers in tumors. IL-1β injection is able to bypass HS+5-FU antitumor effects. In contrast, inHsp70−/−MDSCs, 5-FU-mediated caspase-1 activation is increased in vivo and in vitro without effect on 5-FU cytotoxicity. InHsp70−/−mice, the antitumor effect of 5-FU was impeded, with an increased Th17 and angiogenesis markers in tumors. Finally, the effects of 5-FU on tumor growth can be restored by inhibiting IL-1β, using anakinra.ConclusionThis study provides evidence on the role of HSP70 in tuning 5-FU antitumor effect and suggests that HS can be used to improve 5-FU anticancer effect.


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