31 research outputs found

    Dipole-dipole interaction of Josephson diamagnetic moments

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    The role of dipole-dipole interaction between Josephson diamagnetic moments is considered within a model system of two clusters (each cluster contains three weakly connected superconducting grains). The sign of the resulting critical current is shown to depend on the orientation between clusters, allowing for both 0 and π\pi type junctions behavior. The possibility of the experimental verification of the model predictions is discussed

    Calcium Oxalate Differentiates Human Monocytes Into Inflammatory M1 Macrophages

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    PurposeA number of hyperoxaluric states have been associated with calcium oxalate (CaOx) deposits in the kidneys. In animal models of stone disease, these crystals interact with circulating monocytes that have migrated into the kidney as part of innate immunity. Similarly, macrophages surround CaOx crystals in kidneys of patients excreting high levels of oxalate. We investigate the effect of this exposure and subsequent human immunological response in vitro.Materials and methodsPrimary human monocytes were collected from healthy donors and exposed to CaOx, potassium oxalate, and zinc oxalate (ZnOx). Cytokine production was measured with a multiplex ELISA. Quantitative reverse transcription-polymerase chain reaction was done to validate the mRNA profile expression. M1 macrophage phenotype was confirmed with immunofluorescence microscopy.ResultsBoth primary monocytes and THP-1 cells, a human monocytic cell line, respond strongly to CaOx crystals in a dose-dependent manner producing TNF-α, IL-1β, IL-8, and IL-10 transcripts. Exposure to CaOx followed by 1 h with LPS had an additive effect for cytokine production compared to LPS alone, however, LPS followed by CaOx led to significant decrease in cytokine production. Supernatants taken from monocytes were previously exposed to CaOx crystals enhance M2 macrophage crystal phagocytosis. CaOx, but not potassium or ZnOx, promotes monocyte differentiation into inflammatory M1-like macrophages.ConclusionIn our in vitro experiment, human monocytes were activated by CaOx and produced inflammatory cytokines. Monocytes recognized CaOx crystals through a specific mechanism that can enhance or decrease the innate immune response to LPS. CaOx promoted M1 macrophage development. These results suggest that monocytes have an important role promoting CaOx-induced inflammation

    Enhancing the efficacy of cancer vaccines in urologic oncology: new directions.

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    Immunotherapeutic interventions have long been utilized in urologic oncology for the treatment of metastatic renal cell or superficial transitional cell carcinoma. Most recently, the first active specific immunotherapeutic approach, a cancer vaccine, has passed the final phase of human testing and its approval by the FDA is pending. However, evidence suggests that the full protective and therapeutic potential of cancer vaccines has not yet been achieved. Through multiple mechanisms, tumors promote conditions in the tumor-bearing host that mitigate or even eliminate the vaccine-induced antitumor response. Restoration of the impaired immune function is, therefore, imperative for achieving optimum vaccine efficacy. Targeted pharmacological interventions are capable of overcoming tumor-mediated immunosuppression, and thereby enable cancer vaccination to reach its full therapeutic potential

    STAT1 Signaling Regulates Tumor-Associated Macrophage-Mediated T Cell Deletion

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    High Levels of PD-L1+ and Hyal2+ Myeloid-derived Suppressor Cells in Renal Cell Carcinoma

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    Renal cell carcinoma (RCC) patients frequently have increased number of immunosuppressive myeloid cells in circulation. High number of myeloid-derived suppressor cells (MDSCs) in the blood are associated with immune suppression as well as with cancer-related inflammation which drives the mobilization of myeloid cells to tumor tissue. Here, we show that peripheral blood from a previously untreated RCC patient has increased the number of monocytic CD33+CD11b+ MDSCs, which also co-expressed PD-L1 and membrane-bound enzyme hyaluronidase 2 (Hyal2). PD-L1 expression is associated with immune suppression, whereas expression of Hyal2 is associated with inflammation, because Hyal2+ myeloid cells can degrade the extracellular hyaluronan (HA), leading to the accumulation of pro-inflammatory HA fragments with low molecular weight. These findings implicate the potential involvement of monocytic MDSCs in both tumor-associated immune suppression and cancer-related inflammation. Analysis of organotypic tumor-tissue slice cultures prepared from cancer tissue of the same patient revealed the significant presence of PD-L1+ HLA-DR+ macrophage-like or dendritic cell-like antigen-presenting cells in tumor stroma. Interestingly, stroma-associated PD-L1+ cells frequently have intracellular hyaluronan. Collectively, data presented in this study suggest that the interplay between tumor-recruited myeloid cells and stromal HA may contribute to the inflammation and immune tolerance in kidney cancer

    Generation of antigen-presenting cells from tumor-infiltrated CD11b myeloid cells with DNA demethylating agent 5-aza-2\u27-deoxycytidine.

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    Tumor-recruited CD11b myeloid cells, including myeloid-derived suppressor cells, play a significant role in tumor progression, as these cells are involved in tumor-induced immune suppression and tumor neovasculogenesis. On the other hand, the tumor-infiltrated CD11b myeloid cells could potentially be a source of immunostimulatory antigen-presenting cells (APCs), since most of these cells represent common precursors of both dendritic cells and macrophages. Here, we investigated the possibility of generating mature APCs from tumor-infiltrated CD11b myeloid cells. We demonstrate that in vitro exposure of freshly excised mouse tumors to DNA methyltransferase inhibitor 5-aza-2\u27-deoxycytidine (decitabine, AZA) results in selective elimination of tumor cells, but, surprisingly it also enriches CD45(+) tumor-infiltrated cells. The majority of post-AZA surviving CD45(+) tumor-infiltrated cells were represented by CD11b myeloid cells. A culture of isolated tumor-infiltrated CD11b cells in the presence of AZA and GM-CSF promoted their differentiation into mature F4/80/CD11c/MHC class II-positive APCs. These tumor-derived myeloid APCs produced substantially reduced amounts of immunosuppressive (IL-13, IL-10, PGE(2)), pro-angiogenic (VEGF, MMP-9) and pro-inflammatory (IL-1beta, IL-6, MIP-2) mediators than their precursors, freshly isolated tumor-infiltrated CD11b cells. Vaccinating naïve mice with ex vivo generated tumor-derived APCs resulted in the protection of 70% mice from tumor outgrowth. Importantly, no loading of tumor-derived APC with exogenous antigen was needed to stimulate T cell response and induce the anti-tumor effect. Collectively, our results for the first time demonstrate that tumor-infiltrated CD11b myeloid cells can be enriched and differentiated in the presence of DNA demethylating agent 5-aza-2\u27-deoxycytidine into mature tumor-derived APCs, which could be used for cancer immunotherapy

    Tumor-Associated CD8 +

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    Altered expression of 15-hydroxyprostaglandin dehydrogenase in tumor-infiltrated CD11b myeloid cells: a mechanism for immune evasion in cancer.

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    Many cancers are known to produce high amounts of PGE(2), which is involved in both tumor progression and tumor-induced immune dysfunction. The key enzyme responsible for the biological inactivation of PGE(2) in tissue is NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH). It is well established that cancer cells frequently show down-regulated expression of 15-PGDH, which plays a major role in catabolism of the PGE(2). Here we demonstrate that tumor-infiltrated CD11b cells are also deficient for the 15-PGDH gene. Targeted adenovirus-mediated delivery of 15-PGDH gene resulted in substantial inhibition of tumor growth in mice with implanted CT-26 colon carcinomas. PGDH-mediated antitumor effect was associated with attenuated tumor-induced immune suppression and substantially reduced secretion of immunosuppressive mediators and cytokines such as PGE(2), IL-10, IL-13, and IL-6 by intratumoral CD11b cells. We show also that introduction of 15-PGDH gene in tumor tissue is sufficient to redirect the differentiation of intratumoral CD11b cells from immunosuppressive M2-oriented F4/80(+) tumor-associated macrophages (TAM) into M1-oriented CD11c(+) MHC class II-positive myeloid APCs. Notably, the administration of the 15-PGDH gene alone demonstrated a significant therapeutic effect promoting tumor eradication and long-term survival in 70% of mice with preestablished tumors. Surviving mice acquired antitumor T cell-mediated immune response. This study for the first time demonstrates an important role of the 15-PGDH in regulation of local antitumor immune response and highlights the potential to be implemented to enhance the efficacy of cancer therapy and immunotherapy
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