19 research outputs found

    31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

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    Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

    Incidental acquisition of foreign language vocabulary through brief multi-modal exposure

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    First language acquisition requires relatively little effort compared to foreign language acquisition and happens more naturally through informal learning. Informal exposure can also benefit foreign language learning, although evidence for this has been limited to speech perception and production. An important question is whether informal exposure to spoken foreign language also leads to vocabulary learning through the creation of form-meaning links. Here we tested the impact of exposure to foreign language words presented with pictures in an incidental learning phase on subsequent explicit foreign language learning. In the explicit learning phase, we asked adults to learn translation equivalents of foreign language words, some of which had appeared in the incidental learning phase. Results revealed rapid learning of the foreign language words in the incidental learning phase showing that informal exposure to multi-modal foreign language leads to foreign language vocabulary acquisition. The creation of form-meaning links during the incidental learning phase is discussed

    Homocysteine stimulates phosphorylation of NADPH oxidase p47(phox) and p67(phox) subunits in monocytes via protein kinase Cβ activation

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    Hyperhomocysteinaemia is an independent risk factor for cardiovascular diseases due to atherosclerosis. The development of atherosclerosis involves reactive oxygen species-induced oxidative stress in vascular cells. Our previous study [Wang and O (2001) Biochem. J. 357, 233–240] demonstrated that Hcy (homocysteine) treatment caused a significant elevation of intracellular superoxide anion, leading to increased expression of chemokine receptor in monocytes. NADPH oxidase is primarily responsible for superoxide anion production in monocytes. In the present study, we investigated the molecular mechanism of Hcy-induced superoxide anion production in monocytes. Hcy treatment (20–100 μM) caused an activation of NADPH oxidase and an increase in the superoxide anion level in monocytes (THP-1, a human monocytic cell line). Transfection of cells with p47(phox) siRNA (small interfering RNA) abolished Hcy-induced superoxide anion production, indicating the involvement of NADPH oxidase. Hcy treatment resulted in phosphorylation and subsequently membrane translocation of p47(phox) and p67(phox) subunits leading to NADPH oxidase activation. Pretreatment of cells with PKC (protein kinase C) inhibitors Ro-32-0432 (bisindolylmaleimide XI hydrochloride) (selective for PKCα, PKCβ and PKCγ) abolished Hcy-induced phosphorylation of p47(phox) and p67(phox) subunits in monocytes. Transfection of cells with antisense PKCβ oligonucleotide, but not antisense PKCα oligonucleotide, completely blocked Hcy-induced phosphorylation of p47(phox) and p67(phox) subunits as well as superoxide anion production. Pretreatment of cells with LY333531, a PKCβ inhibitor, abolished Hcy-induced superoxide anion production. Taken together, these results indicate that Hcy-stimulated superoxide anion production in monocytes is regulated through PKC-dependent phosphorylation of p47(phox) and p67(phox) subunits of NADPH oxidase. Increased superoxide anion production via NADPH oxidase may play an important role in Hcy-induced inflammatory response during atherogenesis
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