Expression of Wiskott-Aldrich syndrome protein in dendritic cells regulates synapse formation and activation of naive CD8+ T cells.

The Wiskott-Aldrich syndrome protein (WASp) is a key regulator of actin polimerization in hematopoietic cells. Mutations in WASp cause a severe immunodeficiency characterized by defective initiation of primary immune response and autoimmunity. The contribution of altered dendritic cells (DCs) functions to the disease pathogenesis has not been fully elucidated. In this study, we show that conventional DCs develop normally in WASp-deficient mice. However, Ag targeting to lymphoid organ-resident DCs via anti-DEC205 results in impaired naive CD8(+) T cell activation, especially at low Ag doses. Altered trafficking of Ag-bearing DCs to lymph nodes (LNs) accounts only partially for defective priming because correction of DCs migration does not rescue T cell activation. In vitro and in vivo imaging of DC-T cell interactions in LNs showed that cytoskeletal alterations in WASp null DCs causes a reduction in the ability to form and stabilize conjugates with naive CD8(+) T lymphocytes both in vitro and in vivo. These data indicate that WASp expression in DCs regulates both the ability to traffic to secondary lymphoid organs and to activate naive T cells in LNs.

Nanostructured Zirconia-Based Ceramics and Composites in Dentistry: A State-of-the-Art Review.

The objective of this paper is to review the current knowledge on the development of nanostructured zirconia-based ceramics and composites suitable for application in dentistry. Isi Web of Science, Science Direct, Scientific.net databases, and Google were searched electronically for the period of 1980 to the present, matching the keywords "nano" with the keywords: "Zirconia, ZrO2, Y-TZP, and dental, dentistry". A total of 74 papers were found, with the majority coming from Asia, indicating a more active scientific interest on the topic in this geographic area, followed by Europe, South America, and North America. The research shows, even though the scientific activity on nanostructured ceramics was intense in the last fifteen years, the development of fully dense zirconia-based nanoceramics is yet at an initial stage, most of all from the point of view of the clinical applications. It has been demonstrated that nanostructured ceramics can show improved properties because of the reduction of the grain size to the nanoscale. This is also true for zirconia-based nanoceramics, where some improvements in mechanical, optical, as well as resistance in low-temperature degradation have been observed. Potential applications of this class of material in the dental field are discussed, summarizing the results of the latest scientific research.

Spirituality and Awareness of Diagnoses in Terminally Ill Patients With Cancer.

OBJECTIVE: Aims of the present study were to investigate the association between awareness of own illness condition and psychological outcome in end-of-life phase and to test the association between the spirituality and the awareness of own illness condition. METHODS: Three hundred and ninety-nine terminally ill patients with cancer were enrolled in a hospice in central Italy. One hundred patients satisfied the inclusion criteria. The Systems of Belief Inventory, the Hospital Anxiety and Depression Scale, and a psychological interview to determine the level of awareness of the illness diagnosis (aware; partially aware; and not aware) were administered to terminally ill patients. RESULTS: The main finding was that the awareness of one's own illness condition was positively associated with the extrinsic spirituality and negatively associated with intrinsic spirituality (regression model R = .26; R2 = .07; adjusted R2 = .05; F2, 97 = 3.45; P = .036). The aware group showed lower anxiety and depression ( F2, 97 = 1.9; P = . 075; F2, 97 = 2.6; P = .04) scores than partially aware and not aware groups. The psychological outcome was not associated with the spirituality level. CONCLUSION: In terminally ill patients with cancer, the levels of depression and anxiety were lower in patients aware of their own illness state. Moreover, higher levels of extrinsic and lower levels of intrinsic spirituality predicted the awareness of one's own illness state.

RUN and FYVE domain-containing protein 4 enhances autophagy and lysosome tethering in response to Interleukin-4.

Autophagy is a key degradative pathway coordinated by external cues, including starvation, oxidative stress, or pathogen detection. Rare are the molecules known to contribute mechanistically to the regulation of autophagy and expressed specifically in particular environmental contexts or in distinct cell types. Here, we unravel the role of RUN and FYVE domain-containing protein 4 (RUFY4) as a positive molecular regulator of macroautophagy in primary dendritic cells (DCs). We show that exposure to interleukin-4 (IL-4) during DC differentiation enhances autophagy flux through mTORC1 regulation and RUFY4 induction, which in turn actively promote LC3 degradation, Syntaxin 17-positive autophagosome formation, and lysosome tethering. Enhanced autophagy boosts endogenous antigen presentation by MHC II and allows host control of Brucella abortus replication in IL-4-treated DCs and in RUFY4-expressing cells. RUFY4 is therefore the first molecule characterized to date that promotes autophagy and influences endosome dynamics in a subset of immune cells.

Induction of leukocyte infiltration at metastatic site mediates the protective effect of NGcGM3-based vaccine.

While the NGcGM3/VSSP vaccine, a preparation consisting in very small sized proteoliposomes (VSSP) obtained by the incorporation of the NGcGM3 ganglioside into the outer membrane protein (OMP) complex of Neisseria meningitides, is currently studied in late stage clinical trials in breast cancer and melanoma patients, mechanisms involved in the vaccine's antitumor effect are insufficiently understood. Here we have addressed the role of adaptive and innate immune cells in mediating the protective effect of the vaccine. To this aim we selected the 3LL-D122 Lewis lung spontaneous metastasis model. Unexpectedly, inoculation of the vaccine in tumor bearing C57BL/6 mice, either by subcutaneous (sc) or intraperitoneal (ip) routes, induced similar anti-metastatic effect. Regardless the T-independent nature of NGcGM3 ganglioside as antigen, the antimetastatic effect of NGcGM3/VSSP is dependent on CD4(+) T cells. In a further step we found that the vaccine was able to promote the increase, maturation, and cytokine secretion of conventional DCs and the maturation of Bone Marrow-derived plasmacytoid DCs. In line with this result the in vivo IFNα serum level in ip vaccinated mice increased as soon as 2h after treatment. On the other hand the infiltration of NK1.1(+)CD3(-) and NK1.1(+)CD3(+) cells in lungs of vaccinated mice was significantly increased, compared with the presence of these cells in control animal lungs. In the same way NGcGM3/VSSP mobilized acquired immunity effector cells into the lungs of vaccinated tumor bearing mice. Finally and not less noteworthy, leukocyte infiltration in lungs of tumor bearing mice correlates with vaccine induced inhibition of lung metastization.

Wiskott-Aldrich syndrome protein-mediated actin dynamics control type-I interferon production in plasmacytoid dendritic cells.

Mutations in Wiskott-Aldrich syndrome (WAS) protein (WASp), a regulator of actin dynamics in hematopoietic cells, cause WAS, an X-linked primary immunodeficiency characterized by recurrent infections and a marked predisposition to develop autoimmune disorders. The mechanisms that link actin alterations to the autoimmune phenotype are still poorly understood. We show that chronic activation of plasmacytoid dendritic cells (pDCs) and elevated type-I interferon (IFN) levels play a role in WAS autoimmunity. WAS patients display increased expression of type-I IFN genes and their inducible targets, alteration in pDCs numbers, and hyperresponsiveness to TLR9. Importantly, ablating IFN-I signaling in WASp null mice rescued chronic activation of conventional DCs, splenomegaly, and colitis. Using WASp-deficient mice, we demonstrated that WASp null pDCs are intrinsically more responsive to multimeric agonist of TLR9 and constitutively secrete type-I IFN but become progressively tolerant to further stimulation. By acute silencing of WASp and actin inhibitors, we show that WASp-mediated actin polymerization controls intracellular trafficking and compartmentalization of TLR9 ligands in pDCs restraining exaggerated activation of the TLR9-IFN-α pathway. Together, these data highlight the role of actin dynamics in pDC innate functions and imply the pDC-IFN-α axis as a player in the onset of autoimmune phenomena in WAS disease.

Cdc42-mediated MTOC polarization in dendritic cells controls targeted delivery of cytokines at the immune synapse.

The immune synapse (IS) forms as dendritic cells (DCs) and T cells interact in lymph nodes during initiation of adaptive immunity. Factors that contribute to the formation and maintenance of IS stability and function have been mostly studied in T cells, whereas little is known about events occurring during synapse formation in DCs. Here, we show that DCs activated by Toll-like receptor (TLR) agonists reorient the microtubule-organizing center (MTOC) toward the interacting T cell during antigen-specific synapse formation through a mechanism that depends on the Rho GTPase Cdc42. IL-12, a pivotal cytokine produced by DCs, is found enriched around the MTOC at early time points after TLR ligation and is dragged to the DC-T cell interface in antigen-specific synapses. Synaptic delivery of IL-12 induces activation of pSTAT4 and IFN-γ neosynthesis in CD8(+) naive T cells engaged in antigen-specific conjugates and promotes the survival of antigen-primed T cells. We propose that DC polarization increases the local concentration of proinflammatory mediators at the IS and that this represents a new mechanism by which T cell priming is controlled.