Learn More
Forkhead box O (FOXO) transcription factors favor both T cell quiescence and trafficking through their control of the expression of genes involved in cell cycle progression, adhesion, and homing. In this article, we report that the product of the fam65b gene is a new transcriptional target of FOXO1 that regulates RhoA activity. We show that family with(More)
T cell immune responses begin within organized lymphoid tissues. The pace, topology, and outcomes of the cellular interactions that underlie these responses have, so far, been inferred from static imaging of sectioned tissue or from studies of cultured cells. Here we report dynamic visualization of antigen-specific T cells interacting with dendritic cells(More)
During activation, T cells associate with antigen-presenting cells, a dynamic process that involves the formation of a broad area of intimate membrane contact known as the immunological synapse. The molecular intermediates that link initial antigen recognition to the cytoskeletal changes involved in this phenomenon have not yet been defined. Here we(More)
The development of an effective immune response requires cell-cell contact between T cells and antigen-bearing cells of several types (dendritic cells, B cells, infected tissue cells). Recent advances in light microscopy have led to intense investigation of the molecular events that accompany these cell interactions, especially the redistribution of(More)
Formation of the immunological synapse requires TCR signal-dependent protein redistribution. However, the specific molecular mechanisms controlling protein relocation are not well defined. Moesin is a widely expressed phospho-protein that links many transmembrane molecules to the cortical actin cytoskeleton. Here, we demonstrate that TCR-induced exclusion(More)
Antigen-specific activation of T lymphocytes requires the interaction of their clonally distributed T-cell receptors with plasma membrane ligands composed of foreign peptide antigens bound to major histocompatibility complex molecules. For proliferation and differentiation to ensue, a variety of other adhesive and accessory proteins must also interact with(More)
Naive monoclonal T cells specific for the male antigen can be stimulated in vivo to eliminate male cells and become memory cells or to permit survival of male cells and become tolerant. Memory cells responded to TCR ligation by cyclic oscillations of calcium levels and immediate secretion of very high levels of IL-2 and interferon-gamma. Tolerant cells did(More)
Lymphocyte microvilli mediate initial rolling-adhesion along endothelium but are lost during transmigration from circulation to tissue. However, the mechanism for resorption of lymphocyte microvilli remains unexplored. We show that chemokine stimulation of human peripheral blood T (PBT) cells is sufficient to induce rapid resorption of microvilli.(More)
Antigen recognition was analyzed at the single-cell level by using for the first time T cells which were not altered by in vitro selection, transfection or immortalization. The first consequence of antigen recognition by ex vivo naive CD4+ T cells from T cell receptor (TCR)-transgenic mice is the formation of a "contact zone" with the B cell presenting the(More)
A key feature in T lymphocyte biology is that Th cells rapidly polarize their secretory machinery toward cognate APCs. The molecular mechanisms of these dynamic Th cell responses and their impact on APC biology remain to be elucidated. In this study, we demonstrate that protein kinase Czeta (PKCzeta) is rapidly activated at the immunological synapse (IS) in(More)