HTLV-I infection of WE17/10 CD4+ cell line leads to progressive alteration of Ca2+ influx that eventually results in loss of CD7 expression and activation of an antiapoptotic pathway involving AKT and BAD which paves the way for malignant transformation.

Adult T-cell leukemia/lymphoma (ATLL) is a malignancy slowly emerging from human T-cell leukemia virus type 1 (HTLV-I)-infected mature CD4(+) T-cells. To characterize the molecular modifications induced by HTLV-I infection, we compared HTLV-I-infected WE17/10 cells with control cells, using micro-arrays. Many calcium-related genes were progressively downmodulated over a period of 2 years. Infected cells acquired a profound decrease of intracellular calcium levels in response to ionomycin, timely correlated with decreased CD7 expression. Focusing on apoptosis-related genes and their relationship with CD7, we observed an underexpression of most antiapoptotic genes. Western blotting revealed increasing Akt and Bad phosphorylation, timely correlated with CD7 loss. This was shown to be phosphatidylinositol 3-kinase (PI3K)-dependent. Activation of PI3K/Akt induced resistance to the apoptotic effect of interleukin-2 deprivation. We thus propose the following model: HTLV-I infection induces a progressive decrease in CD3 genes expression, which eventually abrogates CD3 expression; loss of CD3 is known to perturb calcium transport. This perturbation correlates with loss of CD7 expression and induction of Akt and Bad phosphorylation via activation of PI3K. The activation of the Akt/Bad pathway generates a progressive resistance to apoptosis, at a time HTLV-I genes expression is silenced, thus avoiding immune surveillance. This could be a major event in the process of the malignant transformation into ATLL.

Local self-energy approach for electronic structure calculations.

Using a novel self-consistent implementation of Hedin's perturbation theory, we calculate space- and energy-dependent self-energy for a number of materials. We find it to be local in real space and rapidly convergent on second- to third-nearest neighbors. Corrections beyond are evaluated and shown to be completely localized within a single unit cell. This can be viewed as a fully self-consistent implementation of the dynamical mean field theory for electronic structure calculations of real solids using a perturbative impurity solver.

Self-consistent green function approach for calculation of electronic structure in transition metals.

We present an approach for self-consistent calculations of the many-body Green function in transition metals. The distinguishing feature of our approach is the use of one-site approximation and the self-consistent quasiparticle wave function basis set obtained from the solution of the Schrödinger equation with a nonlocal potential. We analyze several sets of skeleton diagrams as generating functionals for the Green function self-energy, including GW and fluctuating exchange sets. Calculations for Fe and Ni revealed stronger energy dependence of the effective interaction and self-energy of the d electrons near the Fermi level compared to s and p electron states.