Human CD1c+ Dendritic Cells Drive the Differentiation of CD103+ CD8+ Mucosal Effector T Cells via the Cytokine TGF-ß Investigators analyzed, by using lung tissues from humans and humanized mice, the role of human CD1c+ and CD141+ dendritic cells (DCs) in determining the type of CD8+ T cell immunity generated to live-attenuated influenza virus vaccine. They found that both lung DC subsets acquired influenza antigens in vivo and expanded specific cytotoxic CD8+ T cells in vitro. [Immunity] Abstract Hunger-Promoting Hypothalamic Neurons Modulate Effector and Regulatory T-Cell Responses The authors showed that selective knockdown of Sirtuin 1 in hypothalamic Agouti-related peptide-expressing neurons, which renders these cells less responsive to cues of low energy availability, significantly promotes CD4+ T-cell activation by increasing production of T helper 1 and 17 proinflammatory cytokines via mediation of the sympathetic nervous system. [Proc Natl Acad Sci USA] Abstract Low-Dose Interleukin-2 Therapy Restores Regulatory T Cell Homeostasis in Patients with Chronic Graft-versus-Host Disease The authors recently reported that daily administration of low-dose interleukin-2 (IL-2) induces selective expansion of functional T regulatory cells and clinical improvement of chronic graft-versus-host disease. To define the mechanisms of action of IL-2 therapy, they examined the immunologic effects of this treatment on homeostasis of CD4+ T cell subsets after transplant. [Sci Trans Med] Abstract Cutting Edge: A Novel, Human-Specific Interacting Protein Couples FOXP3 to a Chromatin-Remodeling Complex that Contains KAP1/TRIM28 Researchers identified and characterized a human-specific FOXP3-interacting protein, referred to as FIK (FOXP3-interacting KRAB domain-containing protein). FIK is highly expressed in regulatory T cells (Tregs) and acts as a bridging molecule to link FOXP3 with the chromatin-remodeling scaffold protein KAP1 (TIF-1ß/TRIM28). Disruption of the FOXP3-FIK-KAP1 complex in Tregs restored expression of FOXP3-target genes and abrogated the suppressor activity of the Tregs. [J Immunol] Abstract Restoring Immune Function of Tumor-Specific CD4+ T Cells during Recurrence of Melanoma Scientists developed a mouse melanoma model in which initial regression of advanced disease was followed by tumor recurrence. During recurrence, Foxp3+ tumor-specific CD4+ T cells became PD-1+ and represented more than 60% of the tumor-specific CD4+ T cells in the host. [J Immunol] Abstract Enrichment of Regulatory T Cells in Invasive Breast Tumor Correlates with the Upregulation of IL-17A Expression and Invasiveness of the Tumor Investigators showed that CD25+CD4+ T cells from PBMCs and tumor express high levels of Foxp3, GITR, CTLA-4 and CD103, indicating that tumor-infiltrating regulatory T cells are functional and possibly recruited by CCL22. Additionally, they observed upregulation of Th17-related molecules (IL-17A, RORC and CCR6) and IL-17A produced by tumor-infiltrating CD4+ and CD8+ T lymphocytes. [Eur J Immunol] Abstract CD4+ T Cells Develop Anti-Retroviral Cytotoxic Activity in the Absence of Regulatory T Cells and CD8+ T Cells Researchers took advantage of a transgenic mouse in which regulatory T cells can be selectively depleted to determine the influence of such cells on retrovirus-specific CD4+ T cell responses during an ongoing infection. [J Virol] Abstract Macrophages as IL-25/IL-33-Responsive Cells Play an Important Role in the Induction of Type 2 Immunity The authors demonstrated that macrophages as IL-25/IL-33-responsive cells play an important role in inducing type 2 immunity using both in vitro and in vivo approaches. [PLoS One] Full Article IFNß Autocrine Feedback Is Required to Sustain TLR Induced Production of MCP-1 in Macrophages Chemokines, including MCP-1, are crucial to mounting an effective immune response due to their ability to recruit other immune cells. The authors showed that sustained LPS or poly(I:C)-stimulated MCP-1 production requires an IFNß-mediated feedback loop. [FEBS Lett] Abstract BATF Regulates the Development and Function of IL-17 Producing iNKT Cells Tg mice overexpressing BATF in T cells were used together with Batf null mice to investigate how altering levels of BATF expression in T cells impacts the development and function of a recently characterized population of iNKT cells expressing IL-17. [BMC Immunol] Abstract | Full Article |