Lineage relationships, homeostasis, and recall capacities of central– and effector–memory CD8 T cells in vivo

The lineage relationships of central–memory T cells (TCM) cells and effector–memory T cells (TEM), as well as their homeostasis and recall capacities, are still controversial. We investigated these issues in a murine model using two complementary approaches: T cell receptor repertoire analysis and adoptive transfer experiments of purified H-Y–specific TCM and TEM populations. Repertoire studies showed that approximately two thirds of TCM and TEM clones derived from a common naive precursor, whereas the other third was distinct. Both approaches highlighted that TCM and TEM had drastically distinct behaviors in vivo, both in the absence of antigen or upon restimulation. TCM clones were stable in the absence of restimulation and mounted a potent and sustained recall response upon secondary challenge, giving rise to both TCM and TEM, although only a fraction of TCM generated TEM. In contrast, TEM persisted for only a short time in the absence of antigen and, although a fraction of them were able to express CD62L, they were unable to mount a proliferative response upon secondary challenge in this model

Scattering theory on graphs

We consider the scattering theory for the Schr\"odinger operator -\Dc_x^2+V(x) on graphs made of one-dimensional wires connected to external leads. We derive two expressions for the scattering matrix on arbitrary graphs. One involves matrices that couple arcs (oriented bonds), the other involves matrices that couple vertices. We discuss a simple way to tune the coupling between the graph and the leads. The efficiency of the formalism is demonstrated on a few known examples.Comment: 21 pages, LaTeX, 10 eps figure

Thymus-specific serine protease contributes to the diversification of the functional endogenous CD4 T cell receptor repertoire

Thymus-specific serine protease expression in stromal as well as hematopoietic cells in the thymus is needed for diversification of the endogenous repertoire of TCRs specific for a particular protein antigen

Novel Insights into the Bovine Polled Phenotype and Horn Ontogenesis in Bovidae

Despite massive research efforts, the molecular etiology of bovine polledness and the developmental pathways involved in horn ontogenesis are still poorly understood. In a recent article, we provided evidence for the existence of at least two different alleles at the Polled locus and identified candidate mutations for each of them. None of these mutations was located in known coding or regulatory regions, thus adding to the complexity of understanding the molecular basis of polledness. We confirm previous results here and exhaustively identify the causative mutation for the Celtic allele (PC) and four candidate mutations for the Friesian allele (PF). We describe a previously unreported eyelash-and-eyelid phenotype associated with regular polledness, and present unique histological and gene expression data on bovine horn bud differentiation in fetuses affected by three different horn defect syndromes, as well as in wild-type controls. We propose the ectopic expression of a lincRNA in PC/p horn buds as a probable cause of horn bud agenesis. In addition, we provide evidence for an involvement of OLIG2, FOXL2 and RXFP2 in horn bud differentiation, and draw a first link between bovine, ovine and caprine Polled loci. Our results represent a first and important step in understanding the genetic pathways and key process involved in horn bud differentiation in Bovidae

Homo/bisexualités et migrations de l'Afrique subsaharienne à la France : quelles émancipations ?

International audienc

Homo/bisexualités et migrations de l'Afrique subsaharienne à la France : quelles émancipations ?

International audienc

Biological and molecular characterisation of the autumn migrants of the bird cherry-oat aphid, Rhopalosiphum padi.

International audienc