Meaning of Education and Wellbeing: Understanding and Preventing the Risk of Loss of Meaning in Students.

The phenomenon of malaise is on the rise at universities, reflecting a deteriorating psychological state that is a combination of anxiety and stress factors. This psychological and emotional upheaval within students is indicative of a fundamental existential issue. In fact, hidden behind the choice of an educational program is the significance given by the student to their life goals.

What Makes Happy Counselors? From Self-Esteem and Leader-Member Exchange to Well-Being at Work: The Mediating Role of Need Satisfaction.

This study was aimed at examining the extent to which well-being at work is linked to self-esteem and psychosocial resources such as leader-member exchange (LMX). Drawing on self-determination theory, we looked at whether psychological needs (perceived autonomy, competence, and relatedness) act as specific mediators between self-esteem and well-being, and between LMX and well-being. Two hundred and twenty four employment counselors (psychologists) from a French national employment office (Pôle emploi) answered a questionnaire.

Characterization of AAV vector particle stability at the single-capsid level.

Virus families have evolved different strategies for genome uncoating, which are also followed by recombinant vectors. Vectors derived from adeno-associated viruses (AAV) are considered as leading delivery tools for in vivo gene transfer, and in particular gene therapy. Using a combination of atomic force microscopy (AFM), biochemical experiments, and physical modeling, we investigated here the physical properties and stability of AAV vector particles.

Perceived Work Conditions and Turnover Intentions: The Mediating Role of Meaning of Work.

Perceived working conditions lead to various negative outcomes for employee behaviors, including turnover intentions. Although potential mediators for these relationships were previously identified, the importance of meaning of work has not yet been investigated. This study examines the role of this psychological resource as a mediator for the relationships between perceived working conditions and turnover intentions in a sample of 336 French workers from different job contexts.

[Atomic force microscopy: a tool to analyze the viral cycle].

Each step of the HIV-1 life cycle frequently involves a change in the morphology and/or mechanical properties of the viral particle or core. The atomic force microscope (AFM) constitutes a powerful tool for characterizing these physical changes at the scale of a single virus. Indeed, AFM enables the visualization of viral capsids in a controlled physiological environment and to probe their mechanical properties by nano-indentation.

RNA control of HIV-1 particle size polydispersity.

HIV-1, an enveloped RNA virus, produces viral particles that are known to be much more heterogeneous in size than is typical of non-enveloped viruses. We present here a novel strategy to study HIV-1 Viral Like Particles (VLP) assembly by measuring the size distribution of these purified VLPs and subsequent viral cores thanks to Atomic Force Microscopy imaging and statistical analysis. This strategy allowed us to identify whether the presence of viral RNA acts as a modulator for VLPs and cores size heterogeneity in a large population of particles.

Induction of high expression of CCR7 and high production of IL-12 in human monocyte-derived dendritic cells by a new bacterial component: LCOS 1013.

Dendritic cells (DCs) are the most potent antigen presenting cells of the immune system as they can act as initiators, stimulators and regulators of the immune response. Human DCs are most commonly generated for clinical use by in vitro differentiation of monocytes with exogenous cytokines. Here, we investigate the effect of LCOS 1013 on the production of mature Mo-DCs.

Identification and quantification of fetal red blood cells in maternal blood by a dual-color flow cytometric method: evaluation of the Fetal Cell Count kit.

Background: As an alternative to the cumbersome Kleihauer-Betke test (KBT), flow cytometry represents a powerful method for the identification and quantification of fetal red blood cells (RBCs) in maternal circulation.

Study Design And Methods: The aim of this study was to evaluate the Fetal Cell Count kit (IQ Products), an innovative flow cytometric method, based on the combination of antibodies directed, respectively, against fetal hemoglobin (HbF) and carbonic anhydrase (CA), a marker expressed after birth, to discriminate fetal RBCs from adult F cells containing HbF. The investigation was performed by two French laboratories that compared the data obtained by flow cytometry and KBT in 455 pregnant or just-delivered women as well as in 124 artificial mixtures containing from 0.

Toll-like receptor 3 (TLR3): a new marker of canine monocytes-derived dendritic cells (cMo-DC).

Toll-like receptors (TLRs) are a family of functionally important receptors for recognition of pathogen-associated molecular pattern (PAMP) since they trigger the pro-inflammatory response and upregulation of costimulatory molecules, linking the rapid innate response to adaptative immunity. In human leukocytes, TLR3 has been found to be specifically expressed in dendritic cells (DC). This study examined the expression of TLR3 in canine monocytes-derived DC (cMo-DC) and PBMC using three new anti-TLR3 mAbs (619F7, 722E2 and 713E4 clones).

SIVSM/HIV-2 Vpx proteins promote retroviral escape from a proteasome-dependent restriction pathway present in human dendritic cells.

Background: Vpx is a non-structural protein coded by members of the SIVSM/HIV-2 lineage that is believed to have originated by duplication of the common vpr gene present in primate lentiviruses. Vpx is incorporated into virion particles and is thus present during the early steps of viral infection, where it is thought to drive nuclear import of viral nucleoprotein complexes. We have previously shown that Vpx is required for SIVMAC-derived lentiviral vectors (LVs) infection of human monocyte-derived dendritic cells (DCs).

Rabbit antithymocyte globulin inhibits monocyte-derived dendritic cells maturation in vitro and polarizes monocyte-derived dendritic cells towards tolerogenic dendritic cells expressing indoleamine 2,3-dioxygenase.

Background: Rabbit antithymocyte globulin (rATG) is a polyclonal mixture of immunoglobulin (Ig) G. It is used to prevent graft rejection and also graft versus host disease after transplantation. Its effect on lymphocyte function has been widely studied.

Alloreaction increases or restores CD40, CD54, and/or HLA molecule expression in acute myelogenous leukemia blasts, through secretion of inflammatory cytokines: Dominant role for TNFbeta, in concert with IFNgamma.

We have previously reported that alloreaction can lead to activation of dendritic cells through secretion of inflammatory cytokines. Here, we addressed whether alloreaction-derived cytokines may also lead to acute myelogenous leukemia (AML) blast differentiation. With this aim, supernatant (sn) harvested from major or minor histocompatibility antigen-mismatched mixed lymphocyte reaction (MLR) were used to culture French American Bristish (FAB) type M4 or M5 AML blasts.

With a little help from a friend: increasing HIV transduction of monocyte-derived dendritic cells with virion-like particles of SIV(MAC).

Modification of dendritic cells (DCs) is a promising avenue for gene therapy purposes, given the versatility and the multiplicity of functions of these cells. In this study, we show that preincubation of monocyte-derived DCs with low amounts of non-infectious virion-like particles derived from the simian immunodeficiency virus (SIV(MAC) VLPs) increases up to 10-fold the efficiency of transduction by HIV-1 lentiviral vectors at low multiplicity of infections yielding up to 90% of transduced cells, in the absence of alterations of DCs behavior. This effect is restricted to DCs and specified by the viral accessory protein Vpx.

Transduction of nondividing human macrophages with gammaretrovirus-derived vectors.

It is commonly accepted that infection of nondividing cells by gammaretroviruses such as the murine leukemia viruses is inefficient due to their inability to cross the nuclear envelope barrier. Challenging this notion, we now show that human nondividing macrophages display a specific window of susceptibility to transduction with a Friend murine leukemia virus (F-MLV)-derived vector during their differentiation from monocytes. This finding suggests that factors other than the nuclear membrane govern permissiveness to gammaretroviral infection and raises the possibility of using the macrophage tropism of F-MLV in gene therapy.

CD86 molecule is a specific marker for canine monocyte-derived dendritic cells.

In this study, canine monocyte-derived dendritic cells (cMo-DC) were produced in presence of canine GM-CSF (cGM-CSF) and canine IL-4 (cIL-4), and they were characterized by their dendritic morphology, MLR functionality and phenotype. We noticed that cMo-DC were labelled with three anti-human CD86 (FUN-1, BU63 and IT2.2 clones), whereas resting and activated lymphocytes or monocytes were not stained.

Integrin alpha1beta1 mediates collagen induction of MMP-13 expression in MC615 chondrocytes.

During endochondral ossification, type I collagen is synthesized by osteoblasts together with some hypertrophic chondrocytes. Type I collagen has also been reported to be progressively synthesized in degenerative joints. Because Matrix Metalloproteinase-13 (MMP-13) plays an active role in remodeling cartilage in fetal development and osteoarthritic cartilage, we investigated whether type I collagen could activate MMP-13 expression in chondrocytes.

Characterization of the typical multidrug resistance profile in human uveal melanoma cell lines and in mouse liver metastasis derivatives.

Uveal melanoma is the most common intraocular malignancy. To study its biology, stable cell lines provide a useful tool, but these are very difficult to obtain. A stable and rapidly growing human choroidal melanoma cell line composed of pure epithelioid cells was established and maintained for at least 4 years.

Evaluation of elutriation and magnetic microbead purification of canine monocytes.

An elutriation technique was developed to obtain large quantities of pure canine monocytes. Firstly, peripheral blood mononuclear cells (PBMC) were isolated from whole blood by Ficoll gradient. Then, the PBMC were separated by an elutriation procedure.

Allogeneic reaction induces dendritic cell maturation through proinflammatory cytokine secretion.

Background: A bone marrow transplantation conditioning regimen is known to activate host dendritic cells (DC), which then become able to initiate graft-versus-host disease (GVHD) by presenting alloantigens. In this article, the authors addressed whether the alloreaction could reciprocally maintain DC in an activation state through secretion of proinflammatory cytokines.

Methods: Skin biopsy specimens from GVHD patients were analyzed for the presence of DC.

Urine mutagenicity and lymphocyte DNA damage in fruit growers occupationally exposed to the fungicide captan.

Aims: To determine haematological parameters, urine mutagenicity (on three Salmonella typhimurium strains), and DNA damage (using the comet assay) in mononuclear leucocytes of farmers before and after a one-day spraying period of pear and apple trees with the fungicide captan in usual conditions.

Methods: Fruit growers were exposed to captan during the 1998 (n = 12) and/or the 2000 spraying seasons (n = 17). Biological samples were collected on the morning of the day of spraying (S1), the evening after spraying (S2), and the morning of the day after (S3).

Normal human keratinocytes bind to the alpha3LG4/5 domain of unprocessed laminin-5 through the receptor syndecan-1.

Basal keratinocytes of the epidermis adhere to their underlying basement membrane through a specific interaction with laminin-5, which is composed by the association of alpha3, beta3, and gamma2 chains. Laminin-5 has the ability to induce either stable cell adhesion or migration depending on specific processing of different parts of the molecule. One event results in the cleavage of the carboxyl-terminal globular domains 4 and 5 (LG4/5) of the alpha3 chain.

Heterologous human immunodeficiency virus type 1 lentiviral vectors packaging a simian immunodeficiency virus-derived genome display a specific postentry transduction defect in dendritic cells.

Heterologous lentiviral vectors (LVs) represent a way to address safety concerns in the field of gene therapy by decreasing the possibility of genetic recombination between vector and packaging constructs and the generation of replication-competent viruses. Using described LVs based on human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus MAC251 (SIV(MAC251)), we asked whether heterologous virion particles in which trans-acting factors belonged to HIV-1 and cis elements belonged to SIV(MAC251) (HIV-siv) would behave as parental homologous vectors in all cell types. To our surprise, we found that although the heterologous HIV-siv vector was as infectious as its homologous counterpart in most human cells, it was defective in the transduction of dendritic cells (DCs) and, to a lesser extent, macrophages.

Generation of monocyte-derived dendritic cells in patients with hereditary hemochromatosis.

Hereditary hemochromatosis (HH) is a common genetic disease with autosomal recessive transmission and is characterized by a dysregulation of iron metabolism, leading to serum iron overload and its progressive accumulation in most body tissues. The effects of HH on the immune system include altered lymphocytosis and functions of monocytes. Moreover, monocytes can differentiate into dendritic cells (DCs), which play crucial roles in the immune response (capture, processing, and presentation of antigen to effector T cells) and this process was shown to be impaired in several pathologies.