Identification of novel helper epitopes of MAGE-A4 tumour antigen: useful tool for the propagation of Th1 cells

MAGE-A4 has been considered as an attractive cancer-testis (CT) antigen for tumour immunotherapy. It has been well accepted that T-helper type 1 (Th1) cell-dominant immunity is critical for the successful induction of antitumour immunity in a tumour-bearing host. The adoptive Th1 cell therapy has been shown to be an attractive strategy for inducing tumour eradication in mouse systems. However, Th1-cell therapy using human tumour-specific Th1 cells, which were expanded from peripheral blood mononuclear cells (PBMCs) in a clinically useful protocol, has never been performed. Here, we first identified MAGE-A4-derived promiscuous helper epitope, peptide (MAGE-A4 280–299), bound to both HLA-DPB1*0501 and DRB1*1403. Using the peptide, we established a suitable protocol for the propagation of MAGE-A4-specific Th1 cells in vitro. Culture of CD4+ T cells with IFN-γ-treated PBMC-derived adherent cells in the presence of helper epitope peptide resulted in a great expansion of MAGE-A4-reactive Th cells producing IFN-γ , but not IL-4. Moreover, it was shown that ligation of MAGE-A4-reactive Th1 cells with the cognate peptide caused the production of IFN-γ and IL-2. Thus, our identified MAGE-A4 helper epitope peptide will become a good tool for the propagation of tumour-specific Th1 cells applicable to adoptive immunotherapy of human cancer

DEFORMATION BEHAVIOUR OF SINGLE CRYSTAL OF Cu-Al MARTENSITIC ALLOYS

Deformation behaviour and stress-induced martensite-martensite transformation of binary Cu-Al β-martensitic alloys were investigated by tensile and compression test, X-ray analysis and electronmicroscopy. Three kinds of Cu-Al alloys having 18R(β'1), 18R+2H, and 2H(β'1) structures in the initial as-quenched state, respectively, were examined. In the specimen with β tensile axis, it was found that deformation proceeds by Lüders deformation. That is, narrow band appears at first and then this "deformation" band propagates along the tensile axis. It was found that in the deformation band region, martensite-martensite transformation, β'1 or γ'1 → α'1(DO22) occurs, by using precession X-ray method. It was also found that γ'1 martensite transformed directly to α'1 martensite without passing the successive γ'1 to β'1 to α'1 transformation like in the Cu-Al-Ni alloys. When the martensite-martensite transformation took place along the whole length of the tensile specimen, single crystal of α'1 martensite was obtained and this α'1 single crystal was stable upon unloading the tensile stress. When the α'1 single crystal specimen which was produced by tensile deformation of the specimen with 2H+18R mixture along [001]β direction, was compressed along [00[MATH]]β (=[00[MATH]]DO22) direction, the reverse transformation α'1 to γ'1 was found to occur without forming β'1 martensite

Martensitic Transformations and Shape Memory Effect in Ti-Ni Sputter-Deposited Thin Films

Films deposited on quartz substrates by sputtering in an argon atmosphere using a sputtering target of a equiatomic TiNi alloy were investigated by differential scanning calorimetry and electron microscopy. The substrate temperature was kept below 423K during sputtering. Transmission electron microscope observation showed that the as-deposited films are amorphous and they crystallize by heating above 750K.The amorphous films were heat treated at various temperatures between 573 and 993K for crystallization. The composition of the films were determined by electron probe micro analysis using a calibration line prepared from bulk samples of well-established compositions. For it was found that Ti content decreases by sputtering, film composition was controlled by placing Ti pieces on the target and changing their sizes. In this way it was successful to obtain films of various composition. By the crystallization heat treatment, no precipitation occurred in the 50.0at%Ti-Ni film, whereas T i 2Ni precipitated in the 53.2at%Ti-Ni and 51.6at% Ti-Ni foils, and Ti3Ni4 precipitated in the 48.6at%Ti-Ni film. The R-phase transformation occurred reversibly on cooling and heating these films in the electron microscope. It was confirmed by constant load thermal cycling tests that the films show a very good shape memory