scholarly journals Myeloid-Derived Suppressor Cells and Pancreatic Cancer: Implications in Novel Therapeutic Approaches

Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1627 ◽  
Author(s):  
Anita Thyagarajan ◽  
Mamdouh Salman A. Alshehri ◽  
Kelly L.R. Miller ◽  
Catherine M. Sherwin ◽  
Jeffrey B. Travers ◽  
...  
Keyword(s):  
Survival Rates ◽  
Suppressor Cells ◽  
Cell Types ◽  
Therapeutic Agents ◽  
Ductal Adenocarcinoma ◽  
Cancer Therapies ◽  
Myeloid Derived Suppressor Cells ◽  
Tumor Resistance ◽  
Cellular Mechanisms ◽  
Immunosuppressive Cell

Pancreatic ductal adenocarcinoma (PDAC) remains a devastating human malignancy with poor prognosis and low survival rates. Several cellular mechanisms have been linked with pancreatic carcinogenesis and also implicated in inducing tumor resistance to known therapeutic regimens. Of various factors, immune evasion mechanisms play critical roles in tumor progression and impeding the efficacy of cancer therapies including PDAC. Among immunosuppressive cell types, myeloid-derived suppressor cells (MDSCs) have been extensively studied and demonstrated to not only support PDAC development but also hamper the anti-tumor immune responses elicited by therapeutic agents. Notably, recent efforts have been directed in devising novel approaches to target MDSCs to limit their effects. Multiple strategies including immune-based approaches have been explored either alone or in combination with therapeutic agents to target MDSCs in preclinical and clinical settings of PDAC. The current review highlights the roles and mechanisms of MDSCs as well as the implications of this immunomodulatory cell type as a potential target to improve the efficacy of therapeutic regimens for PDAC.

scholarly journals Repression of MUC1 promotes expansion and suppressive function of myeloid-derived suppressor cells in pancreatic ductal adenocarcinoma and breast cancer murine models

2020 ◽  
Author(s):  
S. Mahnaz ◽  
L. Das Roy ◽  
M. Bose ◽  
C. De ◽  
S. Nath ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Microenvironment ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Signaling Pathways ◽  
Suppressor Cells ◽  
Ductal Adenocarcinoma ◽  
Myeloid Derived Suppressor Cells ◽  
Mucin 1 ◽  
Transmembrane Glycoprotein ◽  
The Impact

ABSTRACTMyeloid-derived suppressor cells (MDSCs) are immature myeloid cells that are responsible for immunosuppression in tumor microenvironment. Here we report the impact of mucin 1 (MUC1), a transmembrane glycoprotein, on proliferation and functional activity of MDSCs. To determine the role of MUC1 in MDSC phenotype, we analyzed MDSCs derived from wild type (WT) and MUC1-knockout (MUC1KO) mice bearing pancreatic ductal adenocarcinoma KCKO and breast cancer C57MG xenografts. We observed enhanced tumor growth in MUC1KO mice compared to WT mice in both pancreatic KCKO and breast C57MG cancer models due to increased MDSC population and enrichment of Tregs in tumor microenvironment. Our current study shows that knockdown of MUC1 in MDSCs promotes proliferation and immature suppressive phenotype indicated by increased level of iNOS, ARG1 activity and TGF-β secretion under cancer conditions. Increased activity of MDSCs leads to repression of IL-2 and IFN-ɣ production by T-cells. We were able to find that MDSCs from MUC1KO mice have higher levels of c-Myc and activated pSTAT3 as compared to MUC1 WT mice, that are signaling pathways leading to increased survival, proliferation and prevention of maturation. In summary, MUC1 regulates signaling pathways that maintain immunosuppressive properties of MDSCs. Thus, immunotherapy must target only tumor associated MUC1 on epithelial cells and not MUC1 on hematopoietic cells to avoid expansion and suppressive functions of MDSC.

Abstract 87: The Accumulation of Myeloid-derived Suppressor Cells Is a Compensatory Response to the Development of Hypertension

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Xiao Z Shen ◽  
Peng Shi ◽  
Jorge Giani ◽  
Ellen Bernstein ◽  
Kenneth E Bernstein
Keyword(s):  
Blood Pressure ◽  
T Cell ◽  
Angiotensin Ii ◽  
Critical Role ◽  
Myeloid Cells ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Compensatory Response ◽  
Immunosuppressive Cell ◽  
Induced Hypertension

The immune system plays a critical role in the development of hypertension. The immune response consists of pro-inflammatory cells, but also immunosuppressive cells that reduce T cell function. An important category of natural immunosuppressive cell is myeloid-derived suppressor cells (MDSC). We now show that blood and spleen CD11b+ Gr1+ myeloid cells are elevated 2-fold in both angiotensin II and L-NAME induced hypertension. These increased myeloid cells are MDSC in that they elevate IL-4R expression and suppress T cell proliferation. When hypertensive mice were depleted of MDSC, using either anti-Gr1 antibody or gemcitabine, there was a 15 mmHg rise in blood pressure and aggravation of T cells activation with increased production of IFN-γ, TNFα and IL-17 in both spleen and kidney. In contrast, adoptive transfer of MDSC reduced blood pressure in angiotensin-II induced hypertension by 25 mmHg (see Figure). These data suggest a new concept, that the accumulation of MDSC is a compensatory response to the inflammation induced by hypertension. They also indicate that MDSC play an important role in regulating blood pressure.

scholarly journals Defining the emergence of myeloid-derived suppressor cells in breast cancer using single-cell transcriptomics

2020 ◽  
Vol 5 (44) ◽  
pp. eaay6017 ◽  
Author(s):  
Hamad Alshetaiwi ◽  
Nicholas Pervolarakis ◽  
Laura Lynn McIntyre ◽  
Dennis Ma ◽  
Quy Nguyen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Single Cell ◽  
Suppressor Cells ◽  
Gene Signature ◽  
Specific Gene ◽  
Myeloid Derived Suppressor Cells ◽  
Breast Cancers ◽  
Molecular Features ◽  
Immunosuppressive Cell ◽  
Tumor Virus

Myeloid-derived suppressor cells (MDSCs) are innate immune cells that acquire the capacity to suppress adaptive immune responses during cancer. It remains elusive how MDSCs differ from their normal myeloid counterparts, which limits our ability to specifically detect and therapeutically target MDSCs during cancer. Here, we sought to determine the molecular features of breast cancer–associated MDSCs using the widely studied mouse model based on the mouse mammary tumor virus (MMTV) promoter–driven expression of the polyomavirus middle T oncoprotein (MMTV-PyMT). To identify MDSCs in an unbiased manner, we used single-cell RNA sequencing to compare MDSC-containing splenic myeloid cells from breast tumor–bearing mice with wild-type controls. Our computational analysis of 14,646 single-cell transcriptomes revealed that MDSCs emerge through an aberrant neutrophil maturation trajectory in the spleen that confers them an immunosuppressive cell state. We establish the MDSC-specific gene signature and identify CD84 as a surface marker for improved detection and enrichment of MDSCs in breast cancers.

scholarly journals Interaction Between MDSC and NK Cells in Solid and Hematological Malignancies: Impact on HSCT

2021 ◽  
Vol 12 ◽  
Author(s):  
Nicola Tumino ◽  
Anna Laura Di Pace ◽  
Francesca Besi ◽  
Linda Quatrini ◽  
Paola Vacca ◽  
...  
Keyword(s):  
Nk Cells ◽  
Suppressor Cells ◽  
Cell Types ◽  
Hemopoietic Stem Cell ◽  
Cellular Interactions ◽  
Differentiation Potential ◽  
Soluble Factors ◽  
Immune Effector ◽  
Immunosuppressive Cell ◽  
Major Player

Myeloid derived suppressor cells (MDSC) are heterogeneous populations that through the release of soluble factors and/or by cell-to-cell interactions suppress both innate and adaptive immune effector cells. In pathological conditions, characterized by the presence of inflammation, a partial block in the differentiation potential of myeloid precursors causes an accumulation of these immunosuppressive cell subsets both in peripheral blood and in tissues. On the contrary, NK cells represent a major player of innate immunity able to counteract tumor growth. The anti-tumor activity of NK cells is primarily related to their cytolytic potential and to the secretion of soluble factors or cytokines that may act on tumors either directly or indirectly upon the recruitment of other cell types. NK cells have been shown to play a fundamental role in haploidentical hemopoietic stem cell transplantation (HSCT), for the therapy of high-risk leukemias. A deeper analysis of MDSC functional effects demonstrated that these cells are capable, through several mechanisms, to reduce the potent GvL activity exerted by NK cells. It is conceivable that, in this transplantation setting, the MDSC-removal or -inactivation may represent a promising strategy to restore the anti-leukemia effect mediated by NK cells. Thus, a better knowledge of the cellular interactions occurring in the tumor microenvironment could promote the development of novel therapeutic strategies for the treatment of solid and hematological malignances.

scholarly journals Cancer Associated Fibroblast (CAF) regulation of PDAC parenchymal (CPC) and CSC phenotypes is modulated by ECM composition.

2020 ◽  
Author(s):  
Stefania Cannone ◽  
Maria Rafaella Greco ◽  
Hélène Guizouarn ◽  
Olivier Soriani ◽  
Richard Tomasini ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Cell Fate ◽  
Survival Rates ◽  
Vasculogenic Mimicry ◽  
Cell Types ◽  
Collagen I ◽  
Ductal Adenocarcinoma ◽  
Metastatic Progression ◽  
Early Tumor

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest of all cancers having one of the lowest five-year survival rates. One of its hallmarks is a dense desmoplastic stroma consisting in the abnormal accumulation of extracellular matrix (ECM) components, especially Collagen I. This highly fibrotic stroma embeds the bulk cancer (parenchymal) cells (CPCs), cancer stem cells (CSCs) and the main producers of the stromal reaction, the Cancer Associated Fibroblasts (CAFs). Little is known about the role of the acellular ECM in the interplay of the CAFs with the different tumor cell types in determining their phenotypic plasticity and eventual cell fate. Methods Here, we analyzed the role of ECM collagen I in modulating the effect of CAF-derived signals by incubating PDAC CPCs and CSCs grown on ECM mimicking early (low collagen I levels) and late (high collagen I levels) stage PDAC stroma with conditioned medium from primary cultured CAFs derived from patients with PDAC in a previously described three-dimensional (3D) organotypic model of PDAC. Results We found that CAFs (1) reduced CPC growth while favoring CSC growth independently of the ECM; (2) increased the invasive capacity of only CPCs on the ECM mimicking the early tumor and (3) favored vasculogenic mimicry (VM) especially of the CSCs on the ECM mimicking an early tumor. Conclusions: We conclude that the CAFs and acellular stromal components interact to modulate the tumor behaviors of the PDAC CPC and CSC cell types and drive metastatic progression by stimulating the behavior of each tumor cell type that contribute to metastasis: invasion in the CPCs and growth and angiogenesis in the CSCs.

scholarly journals Calcium/Calmodulin Dependent Protein Kinase Kinase 2 Regulates the Expansion of Tumor-Induced Myeloid-Derived Suppressor Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Wei Huang ◽  
Yaping Liu ◽  
Anthony Luz ◽  
Mark Berrong ◽  
Joel N. Meyer ◽  
...  
Keyword(s):  
Immune Response ◽  
Protein Kinase ◽  
Bone Marrow Cells ◽  
Suppressor Cells ◽  
Cell Types ◽  
T Cell Response ◽  
Tumor Rejection ◽  
Myeloid Derived Suppressor Cells ◽  
Calcium Calmodulin Dependent

Myeloid-derived suppressor cells (MDSCs) are a hetero geneous group of cells, which can suppress the immune response, promote tumor progression and impair the efficacy of immunotherapies. Consequently, the pharmacological targeting of MDSC is emerging as a new immunotherapeutic strategy to stimulate the natural anti-tumor immune response and potentiate the efficacy of immunotherapies. Herein, we leveraged genetically modified models and a small molecule inhibitor to validate Calcium-Calmodulin Kinase Kinase 2 (CaMKK2) as a druggable target to control MDSC accumulation in tumor-bearing mice. The results indicated that deletion of CaMKK2 in the host attenuated the growth of engrafted tumor cells, and this phenomenon was associated with increased antitumor T cell response and decreased accumulation of MDSC. The adoptive transfer of MDSC was sufficient to restore the ability of the tumor to grow in Camkk2-/- mice, confirming the key role of MDSC in the mechanism of tumor rejection. In vitro studies indicated that blocking of CaMKK2 is sufficient to impair the yield of MDSC. Surprisingly, MDSC generated from Camkk2-/- bone marrow cells also showed a higher ability to terminally differentiate toward more immunogenic cell types (e.g inflammatory macrophages and dendritic cells) compared to wild type (WT). Higher intracellular levels of reactive oxygen species (ROS) accumulated in Camkk2-/- MDSC, increasing their susceptibility to apoptosis and promoting their terminal differentiation toward more mature myeloid cells. Mechanistic studies indicated that AMP-activated protein kinase (AMPK), which is a known CaMKK2 proximal target controlling the oxidative stress response, fine-tunes ROS accumulation in MDSC. Accordingly, failure to activate the CaMKK2-AMPK axis can account for the elevated ROS levels in Camkk2-/- MDSC. These results highlight CaMKK2 as an important regulator of the MDSC lifecycle, identifying this kinase as a new druggable target to restrain MDSC expansion and enhance the efficacy of anti-tumor immunotherapy.

scholarly journals Calcium/Calmodulin Dependent Protein Kinase Kinase 2 Regulates the Expansion of Tumor-induced Myeloid-Derived Suppressor Cells

2021 ◽  
Author(s):  
Wei Huang ◽  
Yaping Liu ◽  
Anthony Luz ◽  
Mark Berrong ◽  
Joel Meyer ◽  
...  
Keyword(s):  
Immune Response ◽  
Protein Kinase ◽  
Bone Marrow Cells ◽  
Suppressor Cells ◽  
Cell Types ◽  
T Cell Response ◽  
Tumor Rejection ◽  
Myeloid Derived Suppressor Cells ◽  
Calcium Calmodulin Dependent

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of cells, which can suppress the immune response, promote tumor progression and impair the efficacy of immunotherapies. Consequently, the pharmacological targeting of MDSC is emerging as a new immunotherapeutic strategy to stimulate the natural anti-tumor immune response and potentiate the efficacy of immunotherapies. Herein, we leveraged genetically modified models and a small molecule inhibitor to validate Calcium-Calmodulin Kinase Kinase 2 (CaMKK2) as a druggable target to control MDSC accumulation in tumor-bearing mice. The results indicated that deletion of CaMKK2 in the host attenuated the growth of engrafted tumor cells, and this phenomenon was associated with increased antitumor T cell response and decreased accumulation of MDSC. The adoptive transfer of MDSC was sufficient to restore the ability of the tumor to grow in Camkk2-/- mice, confirming the key role of MDSC in the mechanism of tumor rejection. In vitro studies indicated that blocking of CaMKK2 is sufficient to impair the yield of MDSC. Surprisingly, MDSC generated from Camkk2-/- bone marrow cells also showed a higher ability to terminally differentiate toward more immunogenic cell types (e.g inflammatory macrophages and dendritic cells) compared to wild type (WT). Higher intracellular levels of reactive oxygen species (ROS) accumulated in Camkk2-/- MDSC, increasing their susceptibility to apoptosis and promoting their terminal differentiation toward more mature myeloid cells. Mechanistic studies indicated that AMP-activated protein kinase (AMPK), which is a known CaMKK2 proximal target controlling the oxidative stress response, fine-tunes ROS accumulation in MDSC. Accordingly, failure to activate the CaMKK2-AMPK axis can account for the elevated ROS levels in Camkk2-/- MDSC. These results highlight CaMKK2 as an important regulator of the MDSC lifecycle, identifying this kinase as a new druggable target to restrain MDSC expansion and enhance the efficacy of anti-tumor immunotherapy.

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