Myeloid-derived suppressor cells (MDSCs) are important regulators of immune processes during sepsis in mice. However, confirming these observations in humans has been challenging due to the lack of defined preparation protocols and phenotyping schemes for MDSC subsets. Thus, it remains unclear how MDSCs are involved in acute sepsis and whether they have a role in the long-term complications seen in survivors. Here, we combined comprehensive flow cytometry phenotyping with unsupervised clustering using self-organizing maps to identify the three recently defined human MDSC subsets in blood from severe sepsis patients, long-term sepsis survivors, and age-matched controls. We demonstrated the expansion of monocytic M-MDSCs and polymorphonuclear PMN-MDSCs, but not early-stage (e)-MDSCs during acute sepsis. High levels of PMN-MDSCs were also present in long-term survivors many months after discharge, suggesting a possible role in sepsis-related complications. Altogether, by employing unsupervised clustering of flow cytometric data we have confirmed the likely involvement of human MDSC subsets in acute sepsis, and revealed their expansion in sepsis survivors at late time points. The application of this strategy in future studies and in the clinical/diagnostic context would enable rapid progress toward a full understanding of the roles of MDSC in sepsis and other inflammatory conditions.

• Klíčová slova
• Flow cytometry, Multidimensional clustering, Myeloid-derived suppressor cells, Sepsis, Septic shock,
• MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• monocyty imunologie   MeSH
• myeloidní supresorové buňky imunologie   MeSH
• průtoková cytometrie metody   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• sepse imunologie   MeSH
• shluková analýza MeSH
• zánět imunologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Myeloid-derived suppressor cells (MDSC) represent a heterogeneous group of immature myeloid cells with immunoregulatory function in cancer and autoimmune diseases. In humans, two subsets of MDSC were determined based on the characteristic surface markers, monocytic MDSC (M-MDSC) and granulocytic MDSC (G-MDSC). Expansion of MDSC has been reported in some murine models and patients with autoimmune diseases and their immune-suppressive properties were characterized. However, the exact role of MDSC in the pathogenesis of autoimmune diseases is more complex and/or controversial. In type 1 diabetes mellitus (T1D), the increased frequency of MDSC was found in the blood of T1D patients but their suppressor capacity was diminished. In our study, we assessed the role of M-MDSC in the pathogenesis of T1D and showed for the first time the increased frequency of M-MDSC not only in the blood of T1D patients but also in their at-risk relatives compared to healthy donors. T1D patients with inadequate long term metabolic control showed an elevation of M-MDSC compared to patients with better disease control. Furthermore, we described the positive correlation between the percentage of M-MDSC and Th17 cells and IFN-γ producing T cells in T1D patients and their at-risk relatives. Finally, we found that the ability of M-MDSC to suppress autologous T cells is efficient only at the high MDSC: T cells ratio and dependent on cell-cell-contact and TGF-β production. Our data show that the engagement of MDSC in the pathogenesis of T1D is evident, yet not entirely explored and more experiments are required to clarify whether MDSC are beneficial or harmful in T1D.

• MeSH
• buňky Th17 imunologie   MeSH
• diabetes mellitus 1. typu krev   imunologie   MeSH
• dítě MeSH
• interferon gama metabolismus   MeSH
• lidé MeSH
• mladiství MeSH
• myeloidní supresorové buňky imunologie   MeSH
• počet CD4 lymfocytů MeSH
• regulační T-lymfocyty imunologie   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• interferon gama MeSH

Myeloid cells comprise a major component of the tumor microenvironment (TME) that promotes tumor growth and immune evasion. By employing a small-molecule inhibitor of glutamine metabolism, not only were we able to inhibit tumor growth, but we markedly inhibited the generation and recruitment of myeloid-derived suppressor cells (MDSCs). Targeting tumor glutamine metabolism led to a decrease in CSF3 and hence recruitment of MDSCs as well as immunogenic cell death, leading to an increase in inflammatory tumor-associated macrophages (TAMs). Alternatively, inhibiting glutamine metabolism of the MDSCs themselves led to activation-induced cell death and conversion of MDSCs to inflammatory macrophages. Surprisingly, blocking glutamine metabolism also inhibited IDO expression of both the tumor and myeloid-derived cells, leading to a marked decrease in kynurenine levels. This in turn inhibited the development of metastasis and further enhanced antitumor immunity. Indeed, targeting glutamine metabolism rendered checkpoint blockade-resistant tumors susceptible to immunotherapy. Overall, our studies define an intimate interplay between the unique metabolism of tumors and the metabolism of suppressive immune cells.

• Klíčová slova
• Cancer immunotherapy, Immunology, Innate immunity, Oncology,
• MeSH
• buněčná imunita * MeSH
• experimentální nádory imunologie   patologie   terapie   MeSH
• glutamin imunologie   MeSH
• imunoterapie MeSH
• makrofágy imunologie   patologie   MeSH
• myeloidní supresorové buňky imunologie   patologie   MeSH
• myši inbrední BALB C MeSH
• myši knockoutované MeSH
• myši MeSH
• nádorové mikroprostředí imunologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• glutamin MeSH

Many pathogens, ranging from viruses to multicellular parasites, promote expansion of MDSCs, which are myeloid cells that exhibit immunosuppressive features. The roles of MDSCs in infection depend on the class and virulence mechanisms of the pathogen, the stage of the disease, and the pathology associated with the infection. This work compiles evidence supported by functional assays on the roles of different subsets of MDSCs in acute and chronic infections, including pathogen-associated malignancies, and discusses strategies to modulate MDSC dynamics to benefit the host.

• Klíčová slova
• Immunosuppression, Infection, MDSC, Mye-EUNITER, Myeloid regulatory cells, Oncogenic viruses,
• MeSH
• akutní nemoc MeSH
• biologické markery MeSH
• chronická nemoc MeSH
• cílená molekulární terapie MeSH
• imunomodulace MeSH
• infekční nemoci farmakoterapie   etiologie   metabolismus   MeSH
• interakce hostitele a patogenu imunologie   MeSH
• lidé MeSH
• myeloidní supresorové buňky účinky léků   imunologie   metabolismus   MeSH
• náchylnost k nemoci MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• biologické markery MeSH

Myeloid-derived suppressor cells (MDSC) are a heterogeneous group of mononuclear and polymorphonuclear myeloid cells, which are present at very low numbers in healthy subjects, but can expand substantially under disease conditions. Depending on disease type and stage, MDSC comprise varying amounts of immature and mature differentiation stages of myeloid cells. Validated unique phenotypic markers for MDSC are still lacking. Therefore, the functional analysis of these cells is of central importance for their identification and characterization. Various disease-promoting and immunosuppressive functions of MDSC are reported in the literature. Among those, the capacity to modulate the activity of T cells is by far the most often used and best-established read-out system. In this review, we critically evaluate the assays available for the functional analysis of human and murine MDSC under in vitro and in vivo conditions. We also discuss critical issues and controls associated with those assays. We aim at providing suggestions and recommendations useful for the contemporary biological characterization of MDSC.

• Klíčová slova
• Arginase, Immunosuppression, Mye-EUNITER, Myeloid-derived suppressor cells, Proliferation, T cells,
• MeSH
• aktivace lymfocytů imunologie   MeSH
• biologické markery MeSH
• cytokiny metabolismus   MeSH
• fenotyp MeSH
• imunofenotypizace MeSH
• imunomodulace MeSH
• lidé MeSH
• mezibuněčná komunikace imunologie   MeSH
• myeloidní supresorové buňky imunologie   metabolismus   MeSH
• T-lymfocyty imunologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• biologické markery MeSH
• cytokiny MeSH

Myeloid-derived suppressor cells (MDSCs) have been shown to contribute to tumor escape from host immune surveillance and to cancer progression by production of tumor-promoting soluble factors. Granulocyte colony-stimulating factor (G-CSF) is a principle cytokine controlling granulocyte number. Recombinant human G-CSF (rhG-CSF) has become the main therapeutic agent for the treatment of neutropenia and prophylaxis of febrile neutropenia in cancer patients. However, we show here that rhG-CSF triggers accumulation of granulocytic and monocytic subsets. Consequently, we discuss the pharmacological use of granulopoiesis stimulating factors not only in the context of febrile neutropenia but also from the perspective of MDSC-dependent and MDSC-independent mechanisms of immunosuppression and cancer angiogenesis.

• Klíčová slova
• CITIM 2017, Cancer, Granulocyte colony-stimulating factor, Myeloid-derived suppressor cells, Prophylaxis of febrile neutropenia,
• MeSH
• faktor stimulující kolonie granulocytů metabolismus   terapeutické užití   MeSH
• imunologická tolerance MeSH
• lidé MeSH
• myeloidní supresorové buňky imunologie   metabolismus   patologie   MeSH
• nádorová transformace buněk genetika   imunologie   metabolismus   MeSH
• nádory farmakoterapie   imunologie   metabolismus   MeSH
• protinádorové látky terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• faktor stimulující kolonie granulocytů MeSH
• protinádorové látky MeSH

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) contribute to tumor escape from host immune surveillance and to tumor progression by producing tumor-promoting factors. We focused on clinical and analytical MDSCs-related issues as potential biomarkers and immune regulators involved in tumor progression. PATIENTS AND METHODS: We analyzed 10 patients with advanced colorectal carcinoma (CRC) with (M1 subgroup) or without (M0 subgroup) distant metastases at diagnosis. Peripheral blood was collected at diagnosis prior to treatment and subsequently 12 months after therapy initiation. Using multicolor flow cytometry MDSC subsets were evaluated. Monocytic MDSCs (M-MDSCs) were detected as CD45+ CD11b+ CD33+ HLA-DRlow/ CD14+ CD15-, granulocytic MDSCs (CD33hi PMN-MDSC) were detected as CD45+ CD11b+ CD33hi HLA-DRlow/ CD14 CD15+. For analytical and preanalytical studies, random fresh blood specimens predominantly from cancer patients were analyzed. RESULTS: Levels of circulating M-MDSCs were not associated with metastatic disease within advanced CRC patients. Levels of circulating CD33hi PMN-MDSCs were elevated in patients with distant metastases compared to T3 M0 subgroup. Circulating M-MDSCs increased upon treatment initiation in 9 out of 10 patients. CD33hi PMN-MDSCs substantially dropped upon treatment initiation in 5 out of 10 patients and substantially increased in 2 out of 10 patients. Analytical part showed that absolute and relative counts within each MDSC subset are correlated. Coefficient of variation (CV) for repeatability was 6-11% for M-MDSCs and 25-44% for CD33hi PMN-MDSCs. CV for reproducibility was higher with 8-22% for M-MDSCs and 35-79% for CD33hi PMN-MDSCs demonstrating that delay in measurement of MDSCs in whole blood specimen may distort quantification of circulating MDSC subsets. CONCLUSION: The quantification of MDSC subsets is substantially dependent on the type of specimen examined and its preanalytical processing. Exploratory analysis of M-MDSCs and CD33hi PMN-MDSCs in CRC patients revealed different dynamics of M-MDSC and CD33hi PMN-MDSC subsets in the context anti-cancer treatment. Key words: myeloid-derived suppressor cells - preanalytics - colorectal cancer - flow cytometry - immune monitoring.

• Klíčová slova
• myeloid-derived suppressor cells - preanalytics - colorectal cancer - flow cytometry - immune monitoring,
• MeSH
• biologické markery krev   MeSH
• kolorektální nádory krev   imunologie   patologie   terapie   MeSH
• krevní obraz MeSH
• lidé MeSH
• myeloidní supresorové buňky cytologie   imunologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biologické markery MeSH

MDSCs represent one of the key players mediating immunosuppression. These cells accumulate in the TME, lymphoid organs, and blood during tumor growth. Their mobilization was also reported after CY therapy. DNMTi 5AC has been intensively studied as an antitumor agent. In this study, we examined, using two different murine tumor models, the modulatory effects of 5AC on TU-MDSCs and CY-MDSCs tumor growth and CY therapy. Indeed, the percentage of MDSCs in the TME and spleens of 5AC-treated mice bearing TRAMP-C2 or TC-1/A9 tumors was found decreased. The changes in the MDSC percentage were accompanied by a decrease in the Arg-1 gene expression, both in the TME and spleens. CY treatment of the tumors resulted in additional MDSC accumulation in the TME and spleens. This accumulation was subsequently inhibited by 5AC treatment. A combination of CY with 5AC led to the highest tumor growth inhibition. Furthermore, in vitro cultivation of spleen MDSCs in the presence of 5AC reduced the percentage of MDSCs. This reduction was associated with an increased percentage of CD11c+ and CD86+/MHCII+ cells. The observed modulatory effect on MDSCs correlated with a reduction of the Arg-1 gene expression, VEGF production, and loss of suppressive capacity. Similar, albeit weaker effects were observed when MDSCs from the spleens of tumor-bearing animals were cultivated with 5AC. Our findings indicate that beside the direct antitumor effect, 5AC can reduce the percentage of MDSCs accumulating in the TME and spleens during tumor growth and CY chemotherapy, which can be beneficial for the outcome of cancer therapy.

• Klíčová slova
• arginase-1, immunosuppression, microenvironment,
• MeSH
• azacytidin farmakologie   MeSH
• cyklofosfamid farmakologie   MeSH
• experimentální nádory farmakoterapie   imunologie   patologie   MeSH
• myeloidní supresorové buňky imunologie   patologie   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• protokoly protinádorové kombinované chemoterapie farmakologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• azacytidin MeSH
• cyklofosfamid MeSH