55 research outputs found

    miR-155 augments CD8(+) T-cell antitumor activity in lymphoreplete hosts by enhancing responsiveness to homeostatic gamma(c) cytokines

    Get PDF
    Lymphodepleting regimens are used before adoptive immunotherapy to augment the antitumor efficacy of transferred T cells by removing endogenous homeostatic "cytokine sinks." These conditioning modalities, however, are often associated with severe toxicities. We found that microRNA-155 (miR-155) enabled tumor-specific CD8(+) T cells to mediate profound antitumor responses in lymphoreplete hosts that were not potentiated by immune-ablation. miR-155 enhanced T-cell responsiveness to limited amounts of homeostatic gamma c cytokines, resulting in delayed cellular contraction and sustained cytokine production. miR-155 restrained the expression of the inositol 5-phosphatase Ship1, an inhibitor of the serine-threonine protein kinase Akt, and multiple negative regulators of signal transducer and activator of transcription 5 (Stat5), including suppressor of cytokine signaling 1 (Socs1) and the protein tyrosine phosphatase Ptpn2. Expression of constitutively active Stat5a recapitulated the survival advantages conferred by miR-155, whereas constitutive Akt activation promoted sustained effector functions. Our results indicate that overexpression of miR-155 in tumor-specific T cells can be used to increase the effectiveness of adoptive immunotherapies in a cell-intrinsic manner without the need for life-threatening, lymphodepleting maneuvers.112922Ysciescopu

    The MPI Facial Expression Database — A Validated Database of Emotional and Conversational Facial Expressions

    Get PDF
    The ability to communicate is one of the core aspects of human life. For this, we use not only verbal but also nonverbal signals of remarkable complexity. Among the latter, facial expressions belong to the most important information channels. Despite the large variety of facial expressions we use in daily life, research on facial expressions has so far mostly focused on the emotional aspect. Consequently, most databases of facial expressions available to the research community also include only emotional expressions, neglecting the largely unexplored aspect of conversational expressions. To fill this gap, we present the MPI facial expression database, which contains a large variety of natural emotional and conversational expressions. The database contains 55 different facial expressions performed by 19 German participants. Expressions were elicited with the help of a method-acting protocol, which guarantees both well-defined and natural facial expressions. The method-acting protocol was based on every-day scenarios, which are used to define the necessary context information for each expression. All facial expressions are available in three repetitions, in two intensities, as well as from three different camera angles. A detailed frame annotation is provided, from which a dynamic and a static version of the database have been created. In addition to describing the database in detail, we also present the results of an experiment with two conditions that serve to validate the context scenarios as well as the naturalness and recognizability of the video sequences. Our results provide clear evidence that conversational expressions can be recognized surprisingly well from visual information alone. The MPI facial expression database will enable researchers from different research fields (including the perceptual and cognitive sciences, but also affective computing, as well as computer vision) to investigate the processing of a wider range of natural facial expressions

    The Sample Analysis at Mars Investigation and Instrument Suite

    Full text link

    Corruption, political institutions and foreign direct investments: a disagregated study

    No full text
    There is great debate if corruption deters or helps foreign direct investment (FDI). In my dissertation I forward this debate and offer two suggestions. The link between corruption and FDI is best observed at the FDI industrial level. I disaggregate FDI into three dependent variables: market-seeking, labor-seeking and raw materials-seeking FDI. Second I argue the relationship between FDI and corruption is affected by the prevailing political institutions in a host country. I include veto players as a measure of political institutions. I conduct quantitative analyses and results indicate that FDI is indeed a firm level decision. I find that for the most part corruption and weak political institutions are a deterrent to FDI, however, in raw materials-seeking corruption compensates the consequences of a defective bureaucracy and bad policies. These findings show that foreign investors invest in different host environments in pursuit of different institutional advantages. The positive relationship between weak political institutions and corruption on raw materials-seeking FDI should however, not be interpreted as an ultimate institutional advantage. Results indicate that corruption is an effective tool in the short-term only, in the long run, the positive effects of corruption on raw material-seeking FDI diminish indicating that a government's commitment to foreign investments is best signaled by legitimate government institutions. (Published By University of Alabama Libraries
    corecore