Control of RelB during Dendritic Cell Activation Integrates Canonical and Noncanonical NF-κB Pathways Researchers report that RelB promoted dendritic cell activation not as the expected RelB-p52 effector of the noncanonical NF-κB pathway, but as a RelB-p50 dimer regulated by canonical IκBs, IκBα and IκBε. [Nat Immunol] Abstract Identification of Key Regulatory Pathways of Myeloid Differentiation Using an mESC-Based Karyotypically Normal Cell Model Investigators showed that myeloid progenitors can be derived from embryonic stem cells (ESCs), immortalized, and applied to the study of the mechanisms underlying myeloid differentiation. The ESC-derived myeloid progenitors, when immortalized with estrogen-regulated Hoxb8 protein, demonstrate normal karyotyping, are genetically tractable, and can be differentiated into functional neutrophils. [Blood] Abstract | Press Release Intraperitoneal Influx of Neutrophils in Response to IL-33 Is Mast Cell Dependent Findings revealed that interleukin-33 (IL-33) activates mast cells in vivo to recruit neutrophils, a mechanism dependent on IL-33R-expression on peritoneal mast cells. [Blood] Abstract PI3K-PKB Hyperactivation Augments Human Plasmacytoid Dendritic Cell Development and Function Researchers investigated the role of the PI3K-PKB-mTOR axis in human plasmacytoid dendritic cells development, survival and function. [Blood] Abstract Microglial Repopulation Model Reveals a Robust Homeostatic Process for Replacing CNS Myeloid Cells The authors report a model in which a niche for myeloid cells was created through microglia depletion. They showed that microglia-depleted brain regions of CD11b-HSVTK transgenic mice are repopulated with new Iba-1-positive cells within two weeks. The engrafted cells expressed high levels of CD45 and CCR2 and appeared in a wave-like pattern frequently associated with blood vessels, suggesting the engrafted cells were peripheral monocytes. [Proc Natl Acad Sci USA] Abstract | Press Release T Cell Receptor/CARMA1/NF-κB Signaling Controls T-Helper (Th) 17 Differentiation Using genetic mouse models that impede T-cell-nuclear factor κB (NF-κB) signaling either downstream of the T-cell receptor or of IκB kinase β, researchers demonstrated that NF-κB signaling controls not only survival and proliferation of activated T cells, but, if cell survival and cell-cycle progression are enabled, has an additional role in promoting completion of Th17 differentiation. [Proc Natl Acad Sci USA] Abstract Adoptive Transfer of Autologous T Cells Improves T Cell Repertoire Diversity and Long Term B Cell Function in Pediatric Patients with Neuroblastoma Researchers found that the infusion of activated T cells can improve immunologic function especially when given early after hematopoietic stem cell transplantation for children with high-risk neuroblastoma. [Clin Cancer Res] Abstract HIV-1 gp120 Impairs the Induction of B Cell Responses by TLR9-Activated Plasmacytoid Dendritic Cells Data showed that HIV type 1 (HIV-1) gp120 impairs plasmacytoid dendritic cell functions, including activation of B cell responses, implying that TLR9 ligands may not be good adjuvants to use in combination with envelope glycoprotein vaccines. [J Immunol] Abstract In the Presence of IL-21 Human Cord Blood T Cells Differentiate to IL-10 Producing Th1 but Not Th17 or Th2 Cells In umbilical cord blood, researchers demonstrated that interleukin (IL)-21 polarized naive CD4+ T cells into Th1 cells, producing IL-10, a key negative regulator during certain infections and autoimmunity. [Int Immunol] Abstract Induction of M2-Like Macrophages in Recipient NOD-scid Mice by Allogeneic Donor CD4+CD25+ Regulatory T Cells The effect of allogeneic donor CD4+CD25+ regulatory T cells (Tregs) on recipient mouse resident F4/80+macrophages was investigated using a mouse model in which allogeneic donor CD4+CD25+ Tregs were adoptively transferred into the peritoneal cavity of host NOD-scid mice. [Cell Mol Immunol] Abstract |