Converting IL-15 to a superagonist by binding to soluble IL-15Rα

IL-15 is normally presented in vivo as a cell-associated cytokine bound to IL-15Rα. We show here that the biological activity of soluble IL-15 is much improved after interaction with recombinant soluble IL-15Rα; after injection, soluble IL-15/IL-15Rα complexes rapidly induce strong and selective expansion of memory-phenotype CD8(+) cells and natural killer cells. These findings imply that binding of IL-15Rα to IL-15 may create a conformational change that potentiates IL-15 recognition by the βγ(c) receptor on T cells. The enhancing effect of IL-15Rα binding may explain why IL-15 normally functions as a cell-associated cytokine. Significantly, the results with IL-2, a soluble cytokine, are quite different; thus, IL-2 function is markedly inhibited by binding to soluble IL-2Rα

Quad-spectral Unaided Experimental Scanner of Topography on BEXUS 27

This paper describes the REXUS/BEXUS experiment forQuad-spectral Unaided Experimental Scanner of Topography(QUEST). QUEST as part of the REXUS/BEXUS program was designed, developed, built, tested and operated by a team of 17 students from different German universities. It scanned the planet surface by analysingan array of four light sensors (RGB and IR) and two spectrometers. A reusable cluster algorithm determined autonomously onboard an overview image of the surface with marked areas depending on the type of the surface. Furthermore, the algorithm’s data base was generated and optimized before and during flight. Regarding the hardware a modular sensor framework with standardized interfaces was implemented. The project has been a successful step to the designated target to build an autonomous system which could be used in interplanetary missions with demanding constraints on the bandwidth

Interleukin-7 Modulates Anti-Tumor CD8+ T Cell Responses via Its Action on Host Cells.

The adoptive transfer of antigen-specific CD8+ T cells is a promising approach for the treatment of chronic viral and malignant diseases. In order to improve adoptive T cell therapy (ATT) of cancer, recent strategies aim at the antibody-based blockade of immunosuppressive signaling pathways in CD8+ T cells. Alternatively, adjuvant effects of immunostimulatory cytokines might be exploited to improve therapeutic CD8+ T cell responses. For example, Interleukin-7 (IL-7) is a potent growth, activation and survival factor for CD8+ T cells that can be used to improve virus- and tumor-specific CD8+ T cell responses. Although direct IL-7 effects on CD8+ T cells were studied extensively in numerous models, the contribution of IL-7 receptor-competent (IL-7R+) host cells remained unclear. In the current study we provide evidence that CD8+ T cell-mediated tumor rejection in response to recombinant IL-7 (rIL-7) therapy is strictly dependent on IL-7R+ host cells. On the contrary, CD8+ T cell expansion is independent of host IL-7R expression. If, however, rIL-7 therapy and peptide vaccination are combined, host IL-7R signaling is crucial for CD8+ T cell expansion. Unexpectedly, maximum CD8+ T cell expansion relies mainly on IL-7R signaling in non-hematopoietic host cells, similar to the massive accumulation of dendritic cells and granulocytes. In summary, we provide evidence that IL-7R+ host cells are major targets of rIL-7 that modulate therapeutic CD8+ T cell responses and the outcome of rIL-7-assisted ATT. This knowledge may have important implications for the design and optimization of clinical ATT protocols