scholarly journals Myeloid-Derived Suppressor Cells Participate in Preventing Graft Rejection

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Yan Wang ◽  
Xiaodong Gu ◽  
Jianbin Xiang ◽  
Zongyou Chen
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Molecular Mechanisms ◽  
Cell Function ◽  
Suppressor Cells ◽  
Heterogeneous Population ◽  
Myeloid Derived Suppressor Cells ◽  
Transplant Tolerance ◽  
Pathological Conditions ◽  
T Cell Immune Responses

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells and have a tremendous potential to suppress immune responses. MDSCs accumulate during tumor progression, autoimmunity, chronic infection, transplantation, and other pathological conditions and can potently suppress T-cell function. Here, we discuss recent findings that describe the molecular mechanisms of MDSCs suppressing T-cell immune responses as well as recent observations that MDSCs may have roles in transplant tolerance.

scholarly journals Expansion of Monocytic Myeloid-Derived Suppressor Cells Dampens T Cell Function in HIV-1-Seropositive Individuals

2012 ◽  
Vol 87 (3) ◽  
pp. 1477-1490 ◽  
Author(s):  
Aiping Qin ◽  
Weiping Cai ◽  
Ting Pan ◽  
Kang Wu ◽  
Qiong Yang ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Function ◽  
Suppressor Cells ◽  
Cell Contact ◽  
Myeloid Derived Suppressor Cells ◽  
Cell Dysfunction ◽  
Arginase 1 ◽  
T Cell Function ◽  
T Cell Dysfunction ◽  
Hiv 1

ABSTRACTT lymphocyte dysfunction contributes to human immunodeficiency virus type 1 (HIV-1) disease progression by impairing antivirus cellular immunity. However, the mechanisms of HIV-1 infection-mediated T cell dysfunction are not completely understood. Here, we provide evidence that expansion of monocytic myeloid-derived suppressor cells (M-MDSCs) suppressed T cell function in HIV-1-infected individuals. We observed a dramatic elevation of M-MDSCs (HLA-DR−/lowCD11b+CD33+/highCD14+CD15−cells) in the peripheral blood of HIV-1-seropositive subjects (n= 61) compared with healthy controls (n= 51), despite efficacious antiretroviral therapy for nearly 2 years. The elevated M-MDSC frequency in HIV-1+subjects correlated with prognostic HIV-1 disease markers, including the HIV-1 load (r= 0.5957;P< 0.0001), CD4+T cell loss (r= −0.5312;P< 0.0001), and activated T cells (r= 0.4421;P= 0.0004). Functional studies showed that M-MDSCs from HIV-1+subjects suppressed T cell responses in both HIV-1-specific and antigen-nonspecific manners; this effect was dependent on the induction of arginase 1 and required direct cell-cell contact. Further investigations revealed that direct HIV-1 infection or culture with HIV-1-derived Tat protein significantly enhanced human MDSC generationin vitro, and MDSCs from healthy donors could be directly infected by HIV-1 to facilitate HIV-1 replication and transmission, indicating that a positive-feedback loop between HIV-1 infection and MDSC expansion existed. In summary, our studies revealed a novel mechanism of T cell dysfunction in HIV-1-infected individuals and suggested that targeting MDSCs may be a promising strategy for HIV-1 immunotherapy.

scholarly journals MONOCYTES, MACROPHAGES, DENDRITIC AND MYELOID SUPPRESSOR CELLS: GENESIS, CLASSIFICATION, IMMUNOBIOLOGICAL PROPERTIES

2018 ◽  
Vol 15 (3) ◽  
pp. 363-382
Author(s):  
L. P. Titov
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Immune Responses ◽  
Autoimmune Diseases ◽  
Suppressor Cells ◽  
Mononuclear Phagocyte ◽  
Natural Immunity ◽  
Myeloid Suppressor Cells ◽  
T Cell Immune Responses

The article presents the modern data on the most important component of natural immunity – cells of the mononuclear phagocyte system. The questions of origin, the spectrum of expressed markers of differentiation, the classification of monocytes (classical, intermediate, non-classical), macrophages (pro-inflammatory and anti-inflammatory) and dendritic cells (myeloid, plasmacytoid), their immunobiological functions, their role in humoral and T-cell immune responses, anergy and tolerance are considered. The possibility of obtaining cellular immunobiological products (adjuvant and tolerogenic) for immunotherapy of oncological, infectious and autoimmune diseases on their basis is analyzed.

scholarly journals Expansion of Functional Myeloid-Derived Suppressor Cells in Controlled Human Malaria Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Carlos Lamsfus Calle ◽  
Rolf Fendel ◽  
Anurag Singh ◽  
Thomas L. Richie ◽  
Stephen L. Hoffman ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Malaria Infection ◽  
Malaria Vaccine ◽  
Suppressor Cells ◽  
T Cell Proliferation ◽  
Myeloid Derived Suppressor Cells ◽  
Controlled Human Malaria Infection

Malaria can cause life-threatening complications which are often associated with inflammatory reactions. More subtle, but also contributing to the burden of disease are chronic, often subclinical infections, which result in conditions like anemia and immunologic hyporesponsiveness. Although very frequent, such infections are difficult to study in endemic regions because of interaction with concurrent infections and immune responses. In particular, knowledge about mechanisms of malaria-induced immunosuppression is scarce. We measured circulating immune cells by cytometry in healthy, malaria-naïve, adult volunteers undergoing controlled human malaria infection (CHMI) with a focus on potentially immunosuppressive cells. Infectious Plasmodium falciparum (Pf) sporozoites (SPZ) (PfSPZ Challenge) were inoculated during two independent studies to assess malaria vaccine efficacy. Volunteers were followed daily until parasites were detected in the circulation by RT-qPCR. This allowed us to analyze immune responses during pre-patency and at very low parasite densities in malaria-naïve healthy adults. We observed a consistent increase in circulating polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) in volunteers who developed P. falciparum blood stage parasitemia. The increase was independent of preceding vaccination with a pre-erythrocytic malaria vaccine. PMN-MDSC were functional, they suppressed CD4+ and CD8+ T cell proliferation as shown by ex-vivo co-cultivation with stimulated T cells. PMN-MDSC reduced T cell proliferation upon stimulation by about 50%. Interestingly, high circulating PMN-MDSC numbers were associated with lymphocytopenia. The number of circulating regulatory T cells (Treg) and monocytic MDSC (M-MDSC) showed no significant parasitemia-dependent variation. These results highlight PMN-MDSC in the peripheral circulation as an early indicator of infection during malaria. They suppress CD4+ and CD8+ T cell proliferation in vitro. Their contribution to immunosuppression in vivo in subclinical and uncomplicated malaria will be the subject of further research. Pre-emptive antimalarial pre-treatment of vaccinees to reverse malaria-associated PMN-MDSC immunosuppression could improve vaccine response in exposed individuals.

scholarly journals Granulocytic Myeloid-Derived Suppressor Cells Aggravate Tuberculosis Caused by Hypervirulent Mycobacteria

2020 ◽  
Author(s):  
Caio César Barbosa Bomfim ◽  
Eduardo Pinheiro Amaral ◽  
Igor Santiago-Carvalho ◽  
Gislane Almeida Santos ◽  
Érika Machado Salles ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
Cell Function ◽  
Pulmonary Inflammation ◽  
Bacterial Load ◽  
Suppressor Cells ◽  
Myeloid Cell ◽  
Partial Recovery ◽  
Myeloid Derived Suppressor Cells

Abstract Background The role of myeloid-derived suppressor cells (MDSCs) in severe tuberculosis patients who suffer from uncontrolled pulmonary inflammation caused by hypervirulent mycobacterial infection remains unclear. Methods This issue was addressed using C57BL/6 mice infected with highly virulent Mycobacterium bovis strain MP287/03. Results CD11b +GR1 int population increased in the bone marrow, blood and lungs during advanced disease. Pulmonary CD11b +GR1 int (Ly6G intLy6C int) cells showed granularity similar to neutrophils and expressed immature myeloid cell markers. These immature neutrophils harbored intracellular bacilli and were preferentially located in the alveoli. T cell suppression occurred concomitantly with CD11b +GR1 int cell accumulation in the lungs. Furthermore, lung and bone-marrow GR1 + cells suppressed both T cell proliferation and IFN-γ production in vitro. Anti-GR1 therapy given when MDSCs infiltrated the lungs prevented expansion and fusion of primary pulmonary lesions and the development of intragranulomatous caseous necrosis, along with increased mouse survival and partial recovery of T cell function. Lung bacterial load was reduced by anti-GR1 treatment, but mycobacteria released from the depleted cells proliferated extracellularly in the alveoli, forming cords and clumps. Conclusions Granulocytic MDSCs massively infiltrate the lungs during infection with hypervirulent mycobacteria, promoting bacterial growth and the development of inflammatory and necrotic lesions, and are promising targets for host-directed therapies.

Effect of pazopanib on myeloid-derived suppressor cells and T-cell function in patients with metastatic renal cell carcinoma.

2013 ◽  
Vol 31 (6_suppl) ◽  
pp. 455-455
Author(s):  
Kiranpreet K. Khurana ◽  
Pat A. Rayman ◽  
Paul Elson ◽  
Brian I. Rini ◽  
James Finke
Keyword(s):  
T Cell ◽  
Interferon Gamma ◽  
Mononuclear Cells ◽  
Cell Function ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Peripheral Blood Mononuclear ◽  
T Cell Function ◽  
Pre Treatment ◽  
Over Time

455 Background: Tyrosine kinase inhibitors have been shown to have an effect on T cell function. Sunitinib decreases immunosuppression in patients with metastatic renal cell carcinoma (mRCC) as seen by a reduction in myeloid derived suppressor cells (MDSC) that inhibit T cell function. The effect of pazopanib on immune function is unknown. Methods: Peripheral blood mononuclear cells from 21 patients with mRCC treated with pazopanib were thawed for cycle 1 day 1, cycle 1 day 28, cycle 2 day 28, and cycle 4 day 28. Total MDSC and neutrophilic, monocytic, and lineage-negative MDSC subsets were measured by flow cytometry. T cell response was measured by interferon-gamma production after in vitro stimulation by anti-CD3/anti-CD28 beads. Pre-treatment cycle 1 day 1 levels were compared to cycle 4 day 28. Results: In mRCC patients, MDSCs comprise 4.7 % (median, range 1.7-32.9 %) of the peripheral blood mononuclear cells pre-treatment. Neutrophilic MDSC subset is the most prevalent at 2.0 % (median, range 0.3-30.4 %). Monocytic MDSCs comprise 1.5 % (median, range 0.4-5.3 %), and lineage-negative MDSCs comprise only 0.15 % (median, range 0.01-1.03 %). We found that pazopanib does not significantly decrease the percentage of MDSCs (total or subpopulations) over time with the exception of a modest decrease in the lineage-negative MDSC subset (p = 0.08). In terms of T cell function, pre-treatment level of CD3+ interferon-gamma was found to be 10.6 % (median, range 1.3-22.3 %). In contrast, pazopanib significantly increased CD3+ interferon-gamma level over time to 18.1 % (median, range 3.0-25.0 %), p = 0.03. Conclusions: Our study shows that pazopanib does not significantly reduce MDSC levels in patients with mRCC. However, pazopanib improves T cell function over time, as seen by a significant increase in CD3+ interferon-gamma production.

Accumulation of tumor infiltrating myeloid-derived suppressor cells associates with changes in the immune landscape of clear cell renal cell carcinoma.

2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 655-655
Author(s):  
Lin Lin ◽  
Paul G Pavicic ◽  
Patricia A. Rayman ◽  
Charles Tannenbaum ◽  
Brian I. Rini ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Function ◽  
Clear Cell ◽  
Negative Impact ◽  
Multiple Linear Regression Model ◽  
Suppressor Cells ◽  
Rank Test ◽  
Myeloid Derived Suppressor Cells ◽  
Clear Cell Rcc ◽  
Immune Related Genes

655 Background: Myeloid-derived suppressor cells (MDSC) are capable of inducing profound immune suppression of anti-tumor T cell responses. Here we examined the ability of intratumoral MDSC accumulation to alter the immune landscape of RCC and to identify the factors involved. Methods: Using flow cytometry, 41 clear cell RCC nephrectomy samples were assessed for their total MDSC infiltrate and the percentage of granulocytic (PMN-MDSC) or monocytic (M-MDSC) subsets. RNA isolated from these tumor samples and 4 non-tumor samples was also evaluated for expression levels of immune-related genes using a Nanostring PanCancer immune panel. A multiple linear regression model was used to identify which immune-related genes might be significantly associated with PMN-MDSC intratumoral accumulation. Log-Rank test was used for comparison of survival curves. Results: Genes encoding cytokines, cancer-testis antigens, interleukins, and T cell function were differentially expressed by clear cell RCC and the non-tumor samples. The transcription of 55 immune-related genes was significantly associated (FDR adjusted p < 0.05) with PMN-MDSC infiltration, including mediators of MDSC recruitment such as CXCL1, CXCL3, CXCL5, CXCR2, IL8, LIF, S100A8, CSF3R, and CCR3, and molecules governing MDSC expansion and function such as IL10, C/EBPB, CD44, COX2, and NFATC3. When a statistically significant 10 gene signature was analyzed in the context of patient survival using the TCGA database of clear cell RCC patients (n = 945), a strong association between the expression of these genes and reduced survival was observed. Moreover, this association seemed to be additive, with expression of 7-10 of these genes correlating with poorer survival when compared to patients expressing 3 or less (p < 0.0001). Conclusions: Consistent with previous studies defining the immunoregulatory role of MDSCs, these results suggest that MDSC accumulation can alter the inflammatory state of the tumor, and indicate that mediators associated with the function of PMN-MDSCs can have a negative impact on outcome. Mechanistic studies aimed at identifying the functionally relevant mediators are ongoing.

Myeloid Derived Suppressor Cells (MDSCs) Are Increased and Exert Immunosuppressive Activity In CML Patients At Diagnosis

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2711-2711
Author(s):  
Cesarina Giallongo ◽  
Nunziatina Parrinello ◽  
Daniele Tibullo ◽  
Piera La Cava ◽  
Alessandra Romano ◽  
...  
Keyword(s):  
T Cell ◽  
Western Blot ◽  
Cell Function ◽  
Conflicts Of Interest ◽  
Myeloid Cells ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Immunosuppressive Activity ◽  
Arginase 1

Abstract Introduction In some solid tumors it has been demonstrated that a subpopulation of myeloid cells, defined as “myeloid-derived suppressor cells” (MDSCs), plays an important role in inducing T cell tolerance by production of arginase 1 (arg1) that depletes microenvironment of arginine, an essential aminoacid for T cell function. Since chronic myeloid leukemia (CML) patients have high levels of immature myeloid cells it is of interest to investigate if these cells have MDSCs phenotype and activity. The aim of this study was to analyze MDSCs and investigate their activity in CML patients. Methods MDSCs were analyzed in peripheral blood (PB) of 20 healthy donors (HD) and 30 CML patients at diagnosis. In 21 patients MDSCs were also measured during TKI treatment. Granulocytic MDSCs (G-MDSCs) were identified as CD11b+CD33+CD14-HLADR- cells, while the monocytic MDSCs (Mo-MDSCs) as CD14+HLADR by cytofluorimetric analysis. Arg1 expression was assessed using real time PCR and Western Blot. Arg activity was measured in granulocyte lysates using a colorimetric test after enzymatic activation and arginine hydrolysis. Microvesicles (MV) were isolated from CML serum at diagnosis (n=5) by sequential ultracentrifugation. Results CML patients showed high levels of Mo- and G-MDSCs at diagnosis in comparison to HD (41±8 and 82,5±12,2% respectively for CML vs 9±2,1 and 55±5,3% for HD; p<0.001), while after TKIs therapy both subpopulations decreased, returning to normal values. T-reg (CD4+ CD25high Foxp3+ cells) were also significantly increased in CML patients at diagnosis in respect to HD (9±2% vs 6,1±0,8%, p<0.001) with a significant correlation with the percentage of Gr-MDSCs (r=0,6254; p<0.001). Both in PB and purified granulocytic cells, Arg1 expression showed a 30 fold increase in CML at diagnosis compared to HD (p<0.001) and decreased after therapy. The same data were confirmed by Western Blot analysis. Arg enzymatic activity in granulocytes resulted also increased in CML (n=10) compared to HD (n=10) (p<0.001). The suppressive function of CML G-MDSCs was demonstrated by their ability to inhibit the proliferation of CFSE+ HD T cells (p<0.001). In addition, an increase of Mo-MDSCs in vitro was observed after incubation of HD monocytes with CML sera (29±13%; p<0.0001) or MV (8±2,8%; p<0.05). Conclusions MDSCs are increased in CML patients at diagnosis and decrease during TKIs treatment. CML granulocytes have high arg1 activity and immunosuppressive activity. Moreover, CML serum as well as CML microvesicles increase the percentage of HD Mo-MDSCs. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Control of Transplant Tolerance and Intragraft Regulatory T Cell Localization by Myeloid-Derived Suppressor Cells and CCL5

2012 ◽  
Vol 188 (9) ◽  
pp. 4209-4216 ◽  
Author(s):  
Nahzli Dilek ◽  
Nicolas Poirier ◽  
Claire Usal ◽  
Bernard Martinet ◽  
Gilles Blancho ◽  
...  
Keyword(s):  
T Cell ◽  
Regulatory T Cell ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Transplant Tolerance ◽  
Cell Localization
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