Cytotoxic CD8+ T Cells Stimulate Hematopoietic Progenitors by Promoting Cytokine Release from Bone Marrow Mesenchymal Stromal Cells Scientists showed that interferon γ secreted by effector cytotoxic CD8+ T cells stimulates hematopoiesis at the level of early multipotent hematopoietic progenitor cells and induces myeloid differentiation. [Cell Stem Cell] Abstract | Graphical Abstract | Press Release Real-Time Immune Cell Interactions in Target Tissue during Autoimmune-Induced Damage and Graft Tolerance Investigators conducted intravital, longitudinal imaging analyses of cellular behavior in nonlymphoid target tissues to illustrate some key aspects of T cell biology. They used mouse models of T cell-mediated damage and protection of pancreatic islet grafts. [J Exp Med] Abstract Itk-Mediated Integration of T Cell Receptor and Cytokine Signaling Regulates the Balance between Th17 and Regulatory T Cells The authors showed that the Tec family kinase Itk (IL2-inducible T cell kinase), a component of T cell receptor (TCR) signaling pathways, influences this balance by regulating cross talk between TCR and cytokine signaling. [J Exp Med] Abstract Central Memory CD8+ T Lymphocytes Mediate Lung Allograft Acceptance Using a murine model, scientists found that costimulatory blockade-mediated lung allograft acceptance depended on the rapid infiltration of the graft by central memory CD8+ T cells (CD44hiCD62LhiCCR7+). Chemokine receptor signaling and alloantigen recognition were required for trafficking of these memory T cells to lung allografts. [J Clin Invest] Full Article | Press Release Magnetic Field-Induced T Cell Receptor Clustering by Nanoparticles Enhances T Cell Activation and Stimulates Antitumor Activity To enhance T cell activation, a magnetic field was used to drive aggregation of paramagnetic nano-aAPC, resulting in a doubling of T cell receptor cluster size and increased T cell expansion in vitro and after adoptive transfer in vivo. [ACS Nano] Abstract | Press Release Local Immunostimulation Leading to Rejection of Accepted Male Skin Grafts by Female Mice as a Model for Cancer Immunotherapy Female mice of inbred strain CBA do not reject syngeneic male skin grafts even though they mount a T-cell response against the male-specific HY antigen. Investigators showed that local immunostimulation performed by injecting cytokines and Toll-like receptor ligands in close vicinity to the graft causes rejection. [Proc Natl Acad Sci USA] Abstract Foxp3+ T Cells Inhibit Antitumor Immune Memory Modulated by mTOR Inhibition Inhibition of mTOR signaling enhances antitumor memory lymphocytes. However, pharmacologic mTOR inhibition also enhances regulatory T cell (Treg) activity. To counter this effect, Treg-control was added to mTOR inhibition in preclinical models. [Cancer Res] Abstract Tumor-Induced STAT3 Signaling in Myeloid Cells Impairs Dendritic Cell Generation by Decreasing PKCβII Abundance Researchers found in humans and mice that breast cancer cells substantially decreased the abundance of protein kinase C βII (PKCβII) in myeloid progenitor cells through a mechanism involving the enhanced activation of signal transducer and activator of transcription 3 (STAT3) signaling by soluble, tumor-derived factors. [Sci Signal] Abstract MicroRNA-21 Regulates T-Cell Apoptosis by Directly Targeting the Tumor Suppressor Gene Tipe2 The authors report here that microRNA (miR)-21 is a direct target of nuclear factor-κB and could regulate Tipe2 expression in a Tipe2 coding region-dependent manner. In activated T cells and macrophages, Tipe2 expression was markedly downregulated, whereas miR-21 expression was upregulated. [Cell Death Dis] Full Article |