Inverse Identification of Single-Crystal Plasticity Parameters of HCP Zinc from Nanoindentation Curves and Residual Topographies.

This paper investigates the orientation-dependent characteristics of pure zinc under localized loading using nanoindentation experiments and crystal plasticity finite element (CPFEM) simulations. Nanoindentation experiments on different grain orientations exhibited distinct load-depth responses. Atomic force microscopy revealed two-fold unsymmetrical material pile-up patterns. Obtaining crystal plasticity model parameters usually requires time-consuming micromechanical tests. Inverse analysis using experimental and simulated loading-unloading nanoindentation curves of individual grains is commonly used, however the solution to the inverse identification problem is not necessarily unique. In this study, an approach is presented allowing the identification of CPFEM constitutive parameters from nanoindentation curves and residual topographies. The proposed approach combines the response surface methodology together with a genetic algorithm to determine an optimal set of parameters. The CPFEM simulations corroborate with measured nanoindentation curves and residual profiles and reveal the evolution of deformation activity underneath the indenter.

Generation of potent cytotoxic T lymphocytes against castration-resistant prostate cancer cells by dendritic cells loaded with dying allogeneic prostate cancer cells.

To induce a potent cytotoxic T lymphocyte (CTL) response in dendritic cell (DC)-based immunotherapy against prostate cancer, various tumour antigens should be loaded onto DCs. The aim of this study was to establish a method of immunotherapy for castration-resistant prostate cancer (CRPC) using prostate cancer-specific CTLs generated in vitro by DCs. Monocyte-derived DCs from patients with CRPC were induced to mature using a standard cytokine cocktail (in IL-1ß, TNF-α, IL-6 and PGE(2) : standard DCs, sDCs) or using an α-type 1-polarized DC (αDC1) cocktail (in IL-1ß, TNF-α, IFN-α, IFN-γ and polyinosinic:polycytidylic acid) and loaded with the UVB-irradiated CRPC cell line PC-3. Antigen-loaded DCs were evaluated by morphological and functional assays. The αDC1s significantly increased the expression of several molecules related to DC maturation, regardless of whether the αDC1s were loaded with tumour antigens or not, compared to sDCs. The αDC1s showed a higher production of interleukin-12 both during maturation and after subsequent stimulation with CD40L, which was not significantly affected by loading with tumour antigens, as compared to standard DCs (sDCs). Prostate cancer-specific CTLs against autologous CRPC cells were successfully induced by αDC1s loaded with dying PC-3 cells. Autologous αDC1s loaded with an allogeneic CRPC cell line can generate greater CRPC-specific CTL responses as compared to sDCs and may provide a novel source of DC-based vaccines that can be used for the development of immunotherapy in patients with CRPC.

Induction of leukemic-cell-specific cytotoxic T lymphocytes by autologous monocyte-derived dendritic cells presenting leukemic cell antigens.

Leukemic-dendritic cells (leukemic-DCs) have certain limitations, which include difficult generation in 30-40% of patients, and low levels of expression of several key molecules. Therefore, an alternative approach using monocyte-derived DCs pulsed with tumor antigens is required. We investigated the possibility of immunotherapy for AML using leukemic-cell-specific cytotoxic T lymphocytes that were stimulated in vitro by autologous DCs pulsed with tumor antigens. To generate DCs, CD14(+) cells were isolated from peripheral blood mononuclear cells using magnetic-activated cell sorting, and cultured in the presence of GM-CSF and IL-4. On day 6, maturation of DCs was induced by addition of cytokine cocktail (TNF-alpha, IL-1beta, IL-6, and prostaglandin E(2)) for 2 days, and then the mature DCs were pulsed with whole leukemic cell lysates or apoptotic leukemic cells. There were no differences in the phenotypic expressions of mature DCs generated by pulsing with or without leukemic antigens. The mature DCs pulsed with tumor cell lysates or apoptotic leukemic cells showed a higher allostimulatory capacity for allogeneic CD3(+) T cells as compared with mature non-pulsed DCs. Autologous CD3(+) T cells stimulated by the mature pulsed DCs showed more potent cytotoxic activities against autologous leukemic cells than those stimulated by mature non-pulsed DCs. These results suggest that use of DCs pulsed with leukemic cell lysates or apoptotic leukemic cells is a feasible alternative immunotherapeutic approach to overcome the limitations of leukemic-DCs for the treatment of AML patients.