A C3(H20) recycling pathway is a component of the intracellular complement system

An intracellular complement system (ICS) has recently been described in immune and nonimmune human cells. This system can be activated in a convertase-independent manner from intracellular stores of the complement component C3. The source of these stores has not been rigorously investigated. In the present study, Western blotting identified a band corresponding to C3 in freshly isolated human peripheral blood cells that was absent in corresponding cell lines. One difference between native cells and cell lines was the time absent from a fluid-phase complement source; therefore, we hypothesized that loading C3 from plasma was a route of establishing intracellular C3 stores. We found that many types of human cells specifically internalized C3(H(2)O), the hydrolytic product of C3, and not native C3, from the extracellular milieu. Uptake was rapid, saturable, and sensitive to competition with unlabeled C3(H(2)O), indicating a specific mechanism of loading. Under steady-state conditions, approximately 80% of incorporated C3(H(2)O) was returned to the extracellular space. These studies identify an ICS recycling pathway for C3(H(2)O). The loaded C3(H(2)O) represents a source of C3a, and its uptake altered the cytokine profile of activated CD4(+) T cells. Importantly, these results indicate that the impact of soluble plasma factors should be considered when performing in vitro studies assessing cellular immune function

Tumoricidal efficacy coincides with CD11c up-regulation in antigen-specific CD8+ T cells during vaccine immunotherapy

Background: Dendritic cells (DCs) mount tumor-associated antigens (TAAs), and the double-stranded RNA adjuvant Poly(I:C) stimulates Toll-like receptor 3 (TLR3) signal in DC, which in turn induces type I interferon (IFN) and interleukin-12 (IL-12), then cross-primes cytotoxic T lymphocytes (CTLs). Proliferation of CTLs correlates with tumor regression. How these potent cells expand with high quality is crucial to the outcome of CTL therapy. However, good markers reflecting the efficacy of DC-target immunotherapy have not been addressed. Methods: Using an EG7 (ovalbumin, OVA-positive) tumor-implant mouse model, we examined what is a good marker for active CTL induction in treatment with Poly(I:C)/OVA. Results: Simultaneous administration of Poly(I:C) and antigen (Ag) OVA significantly increased a minor population of CD8+ T cells, that express CD11c in lymphoid and tumor sites. The numbers of the CD11c+ CD8+ T cells correlated with those of induced Ag-specific CD8+ T cells and tumor regression. The CD11c+ CD8+ T cell moiety was characterized by its high killing activity and IFN-γ-producing ability, which represent an active phenotype of the effector CTLs. Not only a TLR3-specific (TICAM-1-dependent) signal but also TLR2 (MyD88) signal in DC triggered the expansion of CD11c+ CD8+ T cells in tumor-bearing mice. Notably, human CD11c+ CD8+ T cells also proliferated in peripheral blood mononuclear cells (PBMC) stimulated with cytomegalovirus (CMV) Ag. Conclusions: CD11c expression in CD8+ T cells reflects anti-tumor CTL activity and would be a marker for immunotherapeutic efficacy in mouse models and probably cancer patients as well

Proposal of neutron resonance densitometry for particle like debris of melted fuel using NRTA and NRCA

Neutron resonance densitometry (NRD) has been proposed to quantify nuclear materials in particle-like debris of melted fuel formed in a severe accident of nuclear reactors such as the Fukushima Daiichi nuclear power plants. NRD is a method that combines NRTA (neutron resonance transmission analysis) and NRCA (neutron resonance capture analysis) using a pulsed neutron generator and the TOF (time of flight) technique. NRTA is used to quantify the amount of Pu and U isotopes. NRCA is used to identify matrix materials, such as B and Fe, which are present in the melted fuel. A special gamma-ray spectrometer has been designed to apply NRCA in the presence of highly radioactive materials. The applicability of the NRD method has been studied using Monte Carlo simulations and neutron TOF experiments at the GELINA facility of the EC-JRC-IRMM. We conclude that NRD has a potential to determine the quantities of Pu and U isotopes in particle-like debris of melted fuel with counting statistics uncertainties less than 1%, even in the presence of 2.5 w% natB and 9 w% 56Fe.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Linear response theory in the continuum for deformed nuclei: Green's function vs. time-dependent Hartree-Fock with the absorbing-boundary condition

The continuum random-phase approximation is extended to the one applicable to deformed nuclei. We propose two different approaches. One is based on the use of the three dimensional (3D) Green's function and the other is the small-amplitude TDHF with the absorbing-boundary condition. Both methods are based on the 3D Cartesian grid representation and applicable to systems without any symmetry on nuclear shape. The accuracy and identity of these two methods are examined with the BKN interaction. Using the full Skyrme energy functional in the small-amplitude TDHF approach, we study the isovector giant dipole states in the continuum for O-16 and for even-even Be isotopes.Comment: 15 pages, 8 figure

Triaxial deformation in 10Be

The triaxial deformation in $^{10}$Be is investigated using a microscopic $\alpha+\alpha+n+n$ model. The states of two valence neutrons are classified based on the molecular-orbit (MO) model, and the $\pi$-orbit is introduced about the axis connecting the two $\alpha$-clusters for the description of the rotational bands. There appear two rotational bands comprised mainly of $K^\pi = 0^+$ and $K^\pi = 2^+$, respectively, at low excitation energy, where the two valence neutrons occupy $K^\pi = 3/2^-$ or $K^\pi = 1/2^-$ orbits. The triaxiality and the $K$-mixing are discussed in connection to the molecular structure, particularly, to the spin-orbit splitting. The extent of the triaxial deformation is evaluated in terms of the electro-magnetic transition matrix elements (Davydov-Filippov model, Q-invariant model), and density distribution in the intrinsic frame. The obtained values turned out to be $\gamma = 15^o \sim 20^o$.Comment: 15 pages, latex, 3 figure

Structure of excited states of Be-11 studied with Antisymmetrized Molecular Dynamics

The structures of the ground and excited states of Be-11 were studied with a microscopic method of antisymmetrized molecular dynamics. The theoretical results reproduce the abnormal parity of the ground state and predict various kinds of excited states. We suggest a new negative-parity band with a well-developed clustering structure which reaches high-spin states. Focusing on a $2\alpha$ clustering structure, we investigated structure of the ground and excited states. We point out that molecular orbits play important roles for the intruder ground state and the low-lying $2\hbar \omega$ states. The features of the breaking of $\alpha$ clusters were also studied with the help of data for Gamow-Teller transitions.Comment: 24 pages, 7 figures, to be submitted to Phys.Rev.

Cluster structure in stable and unstable nuclei

Cluster structure in stable and unstable nuclei has been studied. We report recent developments of theoretical studies on cluster aspect, which is essential for structure study of light unstable nuclei. We discuss negative parity bands in even-even Be and Ne isotopes and show the importance of cluster aspect. Three-body cluster structure and cluster crystallization are also introduced. It was found that the coexistence of cluster and mean-field aspect brings a variety of structures to unstable nuclei.Comment: 6 pages, 3 figures, submitted to Euro. Phys. J.

Important role of the spin-orbit interaction in forming the 1/2^+ orbital structure in Be isotopes

The structure of the second 0^+ state of ^{10}Be is investigated using a microscopic $\alpha+\alpha+n+n$ model based on the molecular-orbit (MO) model. The second 0^+ state, which has dominantly the (1/2^+)^2 configuration, is shown to have a particularly enlarged $\alpha-\alpha$ structure. The kinetic energy of the two valence neutrons occupying along the $\alpha-\alpha$ axis is reduced remarkably due to the strong $\alpha$ clustering and, simultaneously, the spin-orbit interaction unexpectedly plays important role to make the energy of this state much lower. The mixing of states with different spin structure is shown to be important in negative-parity states. The experimentally observed small-level spacing between 1^- and 2^- (~ 300 keV) is found to be an evidence of this spin-mixing effect. ^{12}{Be} is also investigated using $\alpha+\alpha+4n$ model, in which four valence neutrons are considered to occupy the (3/2^-)^2(1/2^+)^2 configuration. The energy surface of ^{12}Be is shown to exhibit similar characteristics, that the remarkable $\alpha$ clustering and the contribution of the spin-orbit interaction make the binding of the state with (3/2^-)^2(1/2^+)^2 configuration properly stronger in comparison with the closed p-shell (3/2^-)^2(1/2^-)^2 configuration.Comment: 14 pages, 4 figure

Structure of Excited States of 10Be studied with Antisymmetrized Molecular Dynamics

We study structure of excited states of 10Be with the method of variation after spin parity projection in the framework of antisymmetrized molecular dynamics. Present calculations describe many excited states and reproduce the experimental data of E2 and E1 transitions and the new data of the $\beta$ transition strength successfully. We make systematic discussions on the molecule-like structures of light unstable nuclei and the important role of the valence neutrons based on the results obtained with the framework which is free from such model assumptions as the existence of inert cores and clusters.Comment: 15 pages, RevTex, seven postscript figures (using epsf.sty