Neutrophil Infiltration during Inflammation Is Regulated by PILRα via Modulation of Integrin Activation Scientists found that paired immunoglobulin-like type 2 receptor alpha (PILRα), an inhibitory receptor containing immunoreceptor tyrosine-based inhibitory motifs, negatively regulated neutrophil infiltration during inflammation. [Nat Immunol] Abstract Network Analysis Reveals Centrally Connected Genes and Pathways Involved in CD8+ T Cell Exhaustion versus Memory These studies revealed differences between exhausted and memory CD8+ T cells including the following: lack of coordinated transcriptional modules of quiescence during exhaustion, centrally connected hub genes, pathways such as transcription factors, genes involved in regulation of immune responses, and DNA repair genes, as well as differential connectivity for genes including T-bet, Eomes, and other transcription factors. [Immunity] Abstract IL-7 and IL-15 Instruct the Generation of Human Memory Stem T Cells from Naïve Precursors Researchers showed that it is possible to differentiate in vitro, expand and gene modify in clinically compliant conditions CD8+ memory stem T cells lymphocytes starting from naïve precursors. Requirements for the generation of this T-cell subset, described as CD62L+CCR7+CD45RA+CD45R0+IL-7Rα+CD95+, are CD3/CD28 engagement and culture with IL-7 and IL-15. [Blood] Abstract Tissue-Resident Memory CD8+ T Cells Continuously Patrol Skin Epithelia to Quickly Recognize Local Antigen Investigators demonstrated that antigen-specific CD8+ T cells that remain in skin following herpes simplex virus infection show a steady-state crawling behavior in between keratinocytes. Spatially explicit simulations of the migration of these tissue-resident memory T cells indicate that the migratory dendritic behavior of these cells allows the detection of antigen-expressing target cells in physiologically relevant time frames of minutes to hours. [Proc Natl Acad Sci USA] Abstract | Full Article Interleukin 15 Provides Relief to Cytotoxic T Lymphocytes from Regulatory T Cell-Mediated Inhibition: Implications for Adoptive T-Cell Based Therapies of Lymphoma As recombinant IL-15 is approaching clinical applications, investigators assessed the effects of this cytokine on the proliferation and antitumor activity of cytotoxic T lymphocytes in the presence of regulatory T cells. [Clin Cancer Res] Abstract Preferential Depletion of Gut CD4-Expressing iNKT Cells Contributes to Systemic Immune Activation in HIV-1 Infection Researchers examined key regulatory invariant receptor natural killer T (iNKT) cells in the gut, the largest reservoir of lymphocytes and a key arena of HIV-1 pathogenesis. Results suggested a potentially important contribution of gut iNKT-cell imbalance in determining the systemic immune activation that is the hallmark of HIV-1 pathogenesis. [Mucosal Immunol] Abstract CD8+ T Cells Mediate RAS-Induced Psoriasis-Like Skin Inflammation through IFN-γ Investigators expressed activated H-RASV12G in suprabasal keratinocytes of adult mice and observed rapid development of a psoriasis-like skin phenotype characterized by basal keratinocyte hyperproliferation, acanthosis, hyperkeratosis, intraepidermal neutrophil microabscesses, and increased T helper type 1 (Th1)/Th17 and T cell type 1 (Tc1)/Tc17 skin infiltration. [J Invest Dermatol] Abstract Potent Induction of Antibody-Secreting B Cells by Human Dermal-Derived CD14+ Dendritic Cells Triggered by Dual TLR Ligation The authors showed that CD14+ dermal-derived dendritic cells (DDCs) express mRNA for TLRs 1-9, but respond differentially to single or paired TLR ligands. Compared to single ligands, some combinations were particularly effective at activating CD14+ DDCs, as shown by enhanced expression of B cell stimulatory cytokines and more pronounced phenotypic maturation. [J Immunol] Abstract Regulatory T Cell Kinetics in the Peripheral Blood of Patients with Crohn’s Disease Scientists demonstrated enhanced proliferation within the T regulatory cell population from patients with Crohn’s disease when compared to non-T regulatory cells and T regulatory cells from healthy control subjects. They speculated that T regulatory cells isolated from the periphery of patients with Crohn’s disease experience persistent antigen stimulation resulting in excess proliferative rates. [Hum Immunol] Abstract Dissecting T Cell Contraction In Vivo Using a Genetically Encoded Reporter of Apoptosis Researchers demonstrated that contraction is a widespread process occurring uniformly in all organs tested and targeting phenotypically diverse T cells. Importantly, they identified a critical window of time during which antigen encounters act to antagonize T cell apoptosis, supporting a causal link between antigen clearance and T cell contraction. [Cell Rep] Abstract |