Abstract 553: Ibrutinib, a BTK inhibitor, impairs the generation and function of myeloid derived suppressor cells

Author(s):  
Andrew R. Stiff ◽  
Prashant Trikha ◽  
Robert Wesolowski ◽  
Kari Kendra ◽  
Sarvani Uppati ◽  
...  
2020 ◽  
Vol 69 (11) ◽  
pp. 2233-2245
Author(s):  
Mohammed L. Ibrahim ◽  
Chunwan Lu ◽  
John D. Klement ◽  
Priscilla S. Redd ◽  
Dafeng Yang ◽  
...  

2016 ◽  
Vol 130 (16) ◽  
pp. 1453-1467 ◽  
Author(s):  
Jianjian Ji ◽  
Jingjing Xu ◽  
Shuli Zhao ◽  
Fei Liu ◽  
Jingjing Qi ◽  
...  

Although major advancements have made in investigating the aetiology of SLE (systemic lupus erythaematosus), the role of MDSCs (myeloid-derived suppressor cells) in SLE progression remains confused. Recently, some studies have revealed that MDSCs play an important role in lupus mice. However, the proportion and function of MDSCs in lupus mice and SLE patients are still poorly understood. In the present study, we investigated the proportion and function of MDSCs using different stages of MRL/lpr lupus mice and specimens from SLE patients with different activity. Results showed that splenic granulocytic (G-)MDSCs were significantly expanded by increasing the expression of CCR1 (CC chemokine receptor 1) in diseased MRL/lpr lupus mice and in high-disease-activity SLE patients. However, the proportion of monocytic (M-)MDSCs remains similar in MRL/lpr lupus mice and SLE patients. G-MDSCs produce high levels of ROS (reactive oxygen species) through increasing gp91phox expression, and activated TLR2 (Toll-like receptor 2) and AIM2 (absent in melanoma 2) inflammasome in M-MDSCs lead to IL-1β (interleukin 1β) expression in diseased MRL/lpr mice and high-disease-activity SLE patients. Previous study has revealed that MDSCs could alter the plasticity of Th17 (T helper 17) cells and Tregs (regulatory T-cells) via ROS and IL-1β. Co-culture experiments showed that G-MDSCs impaired Treg differentiation via ROS and M-MDSCs promoted Th17 cell polarization by IL-1β in vitro. Furthermore, adoptive transfer or antibody depletion of MDSCs in MRL/lpr mice confirmed that MDSCs influenced the imbalance of Tregs and Th17 cells in vivo. Our results indicate that MDSCs with the capacity to regulate Th17 cell/Treg balance may be a critical pathogenic factor in SLE.


2019 ◽  
Vol 122 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Cong Hu ◽  
Bo Pang ◽  
Guangzhu Lin ◽  
Yu Zhen ◽  
Huanfa Yi

AbstractIn recent years, a large number of studies have been carried out in the field of immune metabolism, highlighting the role of metabolic energy reprogramming in altering the function of immune cells. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells generated during a large array of pathological conditions, such as cancer, inflammation, and infection, and show remarkable ability to suppress T-cell responses. These cells can also change their metabolic pathways in response to various pathogen-derived or inflammatory signals. In this review, we focus on the roles of glucose, fatty acid (FA), and amino acid (AA) metabolism in the differentiation and function of MDSCs in the tumour microenvironment, highlighting their potential as targets to inhibit tumour growth and enhance tumour immune surveillance by the host. We further highlight the remaining gaps in knowledge concerning the mechanisms determining the plasticity of MDSCs in different environments and their specific responses in the tumour environment. Therefore, this review should motivate further research in the field of metabolomics to identify the metabolic pathways driving the enhancement of MDSCs in order to effectively target their ability to promote tumour development and progression.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4653-4653
Author(s):  
James E Talmadge ◽  
Elizabeth Reed ◽  
Kenneth Cowan ◽  
Dmitry Gabrilovich ◽  
Phyllis Warkentin ◽  
...  

Abstract Myeloid derived suppressor cells (MDSCs) have been reported to be expanded in cancer patients, following growth factor administration and after chemotherapy. These cells have been associated with a loss of T-cell number and function and provide one mechanism of immune evasion. We examined the effect of dose dense chemotherapy on immune phenotypes and function in patients with breast cancers 4 cms or larger and/or four or more involved nodes. The adjuvant therapy was dose-dense doxorubicin, cyclophosphamide (AC) followed by paclitaxel (P), then 33 doses of radiation (R). Blood samples were obtained and studied prior to therapy, 1 week post AC and 1, 15 and 21 weeks post P and then 3, 6 and 12 months later. Flow cytometric analyses of cellular phenotypes were done on these blood specimens and compared to the levels prior to therapeutic intervention and to normal age and sex matched donors. Twenty-three pts have been followed a median of 29 months (range 5.5–50.5 months) from study entry. Two patients relapsed 8 and 23 months after diagnosis. T-cell CD-4 numbers declined following AC from an average of 4.9±0.5 ×106/ml to 1.7±0.3×106/ml, but increased to an average of 2.7± 0.3 × 106/ml, 21 weeks after P or 12 weeks after R. In this study the MDSCs were defined as Lin- (CD3, CD19, CD14 and CD13), HLA-DR- and CD33+. The numbers of MDSCs, which in normal donors were 0.62±0.16×106/ml and in the cancer patients at diagnosis were 11.8±9.6×106/ml increased to 58.4±25.9×106/ml 15 weeks after R. They remained significantly elevated through one year after diagnosis when they were 27.3±12.3×106/ml. The majority of the MDSCs had a high side scatter and forward scatter by flow analysis suggesting a granulocytic commitment rather than a monocytic commitment. The increase in MDSC numbers was apparently associated with R as the numbers of MDSCs were not significantly increased by AC (15.7±13.5×106/ml) or P (10.9±6×106/ml) one week following completion of each cycle of dose dense therapy. In association with the increase in MDSCs there was a significant decrease in PHA proliferation by the peripherial blood mononuclear cells (MNCs) and suppressive activity by irradiated MNC for allergenic lymphocytes.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi125-vi125
Author(s):  
Tyler Alban ◽  
Defne Bayik ◽  
Balint Otvos ◽  
Matthew Grabowski ◽  
Manmeet Ahluwalia ◽  
...  

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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