Gadolinium oxysulfide nanoparticles as multimodal imaging agents for T2-weighted MR, X-ray tomography and photoluminescence.

We have synthesized gadolinium oxysulfide nanoparticles (NPs) doped with other lanthanides (Eu(3+), Er(3+), Yb(3+)) via a hydroxycarbonate precursor precipitation route followed by a sulfuration process under a H2S-Ar atmosphere at 750 °C in order to propose new multimodal nanoplatforms for Magnetic Resonance (MR), X-ray and photoluminescence imaging. Gd2O2S:Eu(3+) NPs strongly absorb near UV (≈ 300-400 nm) and re-emit strong red light (624 nm). They can be easily internalized by cancer cells, and imaged by epifluorescence microscopy under excitation in the NUV (365 nm).

One-step split GFP staining for sensitive protein detection and localization in mammalian cells.

Although epitope tags are useful to detect intracellular proteins and follow their localization with antibodies, background and nonspecific staining often remain problematic. We describe a simple assay based on the split GFP complementation system. Proteins tagged with the 15-amino acid GFP 11 fragment are detected with a solution of the recombinant nonfluorescent complementary GFP 1-10 fragment to reconstitute a fluorescent GFP.

DNA polymerase theta up-regulation is associated with poor survival in breast cancer, perturbs DNA replication, and promotes genetic instability.

"Replicative stress" is one of the main factors underlying neoplasia from its early stages. Genes involved in DNA synthesis may therefore represent an underexplored source of potential prognostic markers for cancer. To this aim, we generated gene expression profiles from two independent cohorts (France, n=206; United Kingdom, n=117) of patients with previously untreated primary breast cancers.

Ligand binding but undetected functional response of FcR after their capture by T cells via trogocytosis.

Intercellular transfer of cell surface proteins by trogocytosis is common and could affect T cell responses. Yet, the role of trogocytosis in T cell function is still elusive, and it is unknown whether a molecule, once captured by T cells, harbors the same biological properties as in donor APC. In this study, we showed that FcgammaR as well as the associated FcRgamma subunit could be detected at high levels on murine and human T cells after their intercellular transfer from FcgammaR-expressing APC.

Capture of plasma membrane fragments from target cells by trogocytosis requires signaling in T cells but not in B cells.

Upon recognition of their respective cellular partners, T and B cells acquire their antigens by a process of membrane capture called trogocytosis. Here, we report that various inhibitors of actin polymerization or of kinases involved in intracellular signaling partially or fully inhibited trogocytosis by CD8(+) and CD4(+) T cells, whereas they had no effect on trogocytosis by B cells. Similarly, trogocytosis by T cells was inhibited at 4 degrees C, whereas in B cells it was independent of temperature, indicating that trogocytosis by B cells does not rely on active processes.

High levels of MeCP2 depress MHC class I expression in neuronal cells.

Background: The expression of MHC class I genes is repressed in mature neurons. The molecular basis of this regulation is poorly understood, but the genes are particularly rich in CpG islands. MeCP2 is a transcriptional repressor that binds to methylated CpG dinucleotides; mutations in this protein also cause the neurodevelopmental disease called Rett syndrome.

Design of an improved set of oligonucleotide primers for genotyping MeCP2tm1.1Bird KO mice by PCR.

Background: The strain of MeCP2tm1.1Bird mice is a broadly used model for Rett syndrome. Because males carrying the invalidated MeCP2 locus are sterile, this strain has to be maintained in a heterozygous state.