Cytometry by Time-of-Flight Shows Combinatorial Cytokine Expression and Virus-Specific Cell Niches within a Continuum of CD8(+) T Cell Phenotypes.
Immunity. 2012 Jan 18;
Authors: Newell EW, Sigal N, Bendall SC, Nolan GP, Davis MM
Abstract
Cytotoxic CD8(+) T lymphocytes directly kill infected or aberrant cells and secrete proinflammatory cytokines. By using metal-labeled probes and mass spectrometric analysis (cytometry by time-of-flight, or CyTOF) of human CD8(+) T cells, we analyzed the expression of many more proteins than previously possible with fluorescent labels, including surface markers, cytokines, and antigen specificity with modified peptide-MHC tetramers. With 3-dimensional principal component analysis (3D-PCA) to display phenotypic diversity, we observed a relatively uniform pattern of variation in all subjects tested, highlighting the interrelatedness of previously described subsets and the continuous nature of CD8(+) T cell differentiation. These data also showed much greater complexity in the CD8(+) T cell compartment than previously appreciated, including a nearly combinatorial pattern of cytokine expression, with distinct niches occupied by virus-specific cells. This large degree of functional diversity even between cells with the same specificity gives CD8(+) T cells a remarkable degree of flexibility in responding to pathogens.
PMID: 22265676 [PubMed - as supplied by publisher]
Syk Kinase-Coupled C-type Lectin Receptors Engage Protein Kinase C-δ to Elicit Card9 Adaptor-Mediated Innate Immunity.
Immunity. 2012 Jan 18;
Authors: Strasser D, Neumann K, Bergmann H, Marakalala MJ, Guler R, Rojowska A, Hopfner KP, Brombacher F, Urlaub H, Baier G, Brown GD, Leitges M, Ruland J
Abstract
C-type lectin receptors (CLRs) that couple with the kinase Syk are major pattern recognition receptors for the activation of innate immunity and host defense. CLRs recognize fungi and other forms of microbial or sterile danger, and they induce inflammatory responses through the adaptor protein Card9. The mechanisms relaying CLR proximal signals to the core Card9 module are unknown. Here we demonstrated that protein kinase C-δ (PKCδ) was activated upon Dectin-1-Syk signaling, mediated phosphorylation of Card9 at Thr231, and was responsible for Card9-Bcl10 complex assembly and canonical NF-κB control. Prkcd(-/-) dendritic cells, but not those lacking PKCα, PKCβ, or PKCθ, were defective in innate responses to Dectin-1, Dectin-2, or Mincle stimulation. Moreover, Candida albicans-induced cytokine production was blocked in Prkcd(-/-) cells, and Prkcd(-/-) mice were highly susceptible to fungal infection. Thus, PKCδ is an essential link between Syk activation and Card9 signaling for CLR-mediated innate immunity and host protection.
PMID: 22265677 [PubMed - as supplied by publisher]
The Transcription Factors T-bet and Eomes Control Key Checkpoints of Natural Killer Cell Maturation.
Immunity. 2012 Jan 18;
Authors: Gordon SM, Chaix J, Rupp LJ, Wu J, Madera S, Sun JC, Lindsten T, Reiner SL
Abstract
Natural killer (NK) cells play critical roles defending against tumors and pathogens. We show that mice lacking both transcription factors Eomesodermin (Eomes) and T-bet failed to develop NK cells. Developmental stability of immature NK cells constitutively expressing the death ligand TRAIL depended on T-bet. Conversely, maturation characterized by loss of constitutive TRAIL expression and induction of Ly49 receptor diversity and integrin CD49b (DX5(+)) required Eomes. Mature NK cells from which Eomes was deleted reverted to phenotypic immaturity if T-bet was present or downregulated NK lineage antigens if T-bet was absent, despite retaining expression of Ly49 receptors. Fetal and adult hepatic hematopoiesis restricted Eomes expression and limited NK development to the T-bet-dependent, immature stage, whereas medullary hematopoiesis permitted Eomes-dependent NK maturation in adult mice. These findings reveal two sequential, genetically separable checkpoints of NK cell maturation, the progression of which is metered largely by the anatomic localization of hematopoiesis.
PMID: 22261438 [PubMed - as supplied by publisher]
Transcription of Il17 and Il17f Is Controlled by Conserved Noncoding Sequence 2.
Immunity. 2012 Jan 11;
Authors: Wang X, Zhang Y, Yang XO, Nurieva RI, Chang SH, Ojeda SS, Kang HS, Schluns KS, Gui J, Jetten AM, Dong C
Abstract
T helper 17 (Th17) cells specifically transcribe the Il17 and Il17f genes, which are localized in the same chromosome region, but the underlying mechanism is unclear. Here, we report a cis element that we previously named conserved noncoding sequence 2 (CNS2) physically interacted with both Il17 and Il17f gene promoters and was sufficient for regulating their selective transcription in Th17 cells. Targeted deletion of CNS2 resulted in impaired retinoic acid-related orphan receptor gammat (RORγt)-driven IL-17 expression in vitro. CNS2-deficient T cells also produced substantially decreased amounts of IL-17F. These cytokine defects were associated with defective chromatin remodeling in the Il17-Il17f gene locus, possibly because of effects on CNS2-mediated recruitment of histone-modifying enzymes p300 and JmjC domain-containing protein 3 (JMJD3). CNS2-deficient animals were also shown to be resistant to experimental autoimmune encephalomyelitis (EAE). Our results thus suggest that CNS2 is sufficient and necessary for Il17 and optimal Il17f gene transcription in Th17 cells.
PMID: 22244845 [PubMed - as supplied by publisher]
RAE1ε Ligand Expressed on Pancreatic Islets Recruits NKG2D Receptor-Expressing Cytotoxic T Cells Independent of T Cell Receptor Recognition.
Immunity. 2012 Jan 11;
Authors: Markiewicz MA, Wise EL, Buchwald ZS, Pinto AK, Zafirova B, Polic B, Shaw AS
Abstract
The mechanisms by which cytotoxic T lymphocytes (CTLs) enter and are retained in nonlymphoid tissue are not well characterized. With a transgenic mouse expressing the NKG2D ligand retinoic acid early transcript 1ε (RAE1ε) in β-islet cells of the pancreas, we found that RAE1 expression was sufficient to induce the recruitment of adoptively transferred CTLs to islets. This was dependent on NKG2D expression by the CTLs and independent of antigen recognition. Surprisingly, the recruitment of CTLs resulted in the subsequent recruitment of a large number of endogenous lymphocytes. Whereas transgenic mice did not develop diabetes, RAE1 expression was sufficient to induce insulitis in older, unmanipulated transgenic mice that was enhanced by viral infection and pancreatic inflammation. These results demonstrate that the expression of an NKG2D ligand in islets is sufficient to recruit CTLs regardless of their antigen specificity and to induce insulitis.
PMID: 22244846 [PubMed - as supplied by publisher]
TAK1 Negatively Regulates NF-κB and p38 MAP Kinase Activation in Gr-1(+)CD11b(+) Neutrophils.
Immunity. 2012 Jan 4;
Authors: Alagbala Ajibade A, Wang Q, Cui J, Zou J, Xia X, Wang M, Tong Y, Hui W, Liu D, Su B, Wang HY, Wang RF
Abstract
Stringent control of NF-κB and mitogen-activated protein kinase (MAPK) signaling is critical during innate immune responses. TGF-β activated kinase-1 (TAK1) is essential for NF-κB activation in T and B cells but has precisely the opposite activity in myeloid cells. Specific deletion of TAK1 (Map3k7(ΔM/ΔM)) led to development of splenomegaly and lymphomegaly associated with neutrophilia. Compared with wild-type cells, TAK1-deficient neutrophils enhanced the phosphorylation of the kinases IKK, p38, and JNK and the production of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), and reactive oxygen species (ROS) after lipopolysaccharide (LPS) stimulation. Map3k7(ΔM/ΔM) mice were significantly more susceptible to LPS-induced septic shock and produced higher amounts of IL-1β, IL-6, and TNF-α in plasma than do wild-type mice. Specific ablation of p38 rescued the phenotype and functional properties of Map3k7(ΔM/ΔM) mice. Our findings identify a previously unrecognized role of TAK1 as a negative regulator of p38 and IKK activation in a cell type-specific manner.
PMID: 22226633 [PubMed - as supplied by publisher]
Monocyte subsets responsible for immunoglobulin g-dependent effector functions in vivo.
Immunity. 2011 Dec 23;35(6):932-44
Authors: Biburger M, Aschermann S, Schwab I, Lux A, Albert H, Danzer H, Woigk M, Dudziak D, Nimmerjahn F
Abstract
Immunoglobulin G (IgG) antibodies confer protection against pathogenic microorganisms, serve as therapeutics in tumor therapy, and are involved in destruction of healthy tissues during autoimmune diseases. Understanding the molecular pathways and effector cell types involved in antibody-mediated effector functions is a prerequisite to modulate these activities. In this study we used two independent model systems to identify innate immune effector cells required for IgG activity in vivo. We first defined the precise repertoire of receptors for the IgG Fc fragment (FcγR) on innate immune effector cells in the blood and on tissue-resident macrophage populations. Despite expression of relevant activating FcγRs on various phagocyte populations, our data indicate that the majority of these cell types are dispensable for IgG activity in vivo. In contrast, IgG-dependent effector functions were selectively impaired in animals lacking the CX(3)CR1(hi)Ly6C(lo)CD11c(int) monocyte subset, which expressed the full set of FcγRs required for IgG activity.
Control of B Cell Development by the Histone H2A Deubiquitinase MYSM1.
Immunity. 2011 Dec 23;35(6):883-96
Authors: Jiang XX, Nguyen Q, Chou Y, Wang T, Nandakumar V, Yates P, Jones L, Wang L, Won H, Lee HR, Jung JU, Müschen M, Huang XF, Chen SY
Abstract
Epigenetic histone modifications play critical roles in the control of gene transcription. Recently, an increasing number of histone H2A deubiquitinases have been identified and characterized. However, the physiological functions for this entire group of histone H2A deubiquitinases remain unknown. In this study, we revealed that the histone H2A deubiquitinase MYSM1 plays an essential and intrinsic role in early B cell development. MYSM1 deficiency results in a block in early B cell commitment and a defect of B cell progenitors in expression of EBF1 and other B lymphoid genes. We further demonstrated that MYSM1 derepresses EBF1 transcription in B cell progenitors by orchestrating histone modifications and transcription factor recruitment to the EBF1 locus. Thus, this study not only uncovers the essential role for MYSM1 in gene transcription during early B cell development but also underscores the biological significance of reversible epigenetic histone H2A ubiquitination.
The Aryl Hydrocarbon Receptor Regulates Gut Immunity through Modulation of Innate Lymphoid Cells.
Immunity. 2011 Dec 14;
Authors: Qiu J, Heller JJ, Guo X, Chen ZM, Fish K, Fu YX, Zhou L
Abstract
Innate lymphoid cells (ILCs) expressing the nuclear receptor RORγt are essential for gut immunity presumably through production of interleukin-22 (IL-22). The molecular mechanism underlying the development of RORγt(+) ILCs is poorly understood. Here, we have shown that the aryl hydrocarbon receptor (Ahr) plays an essential role in RORγt(+) ILC maintenance and function. Expression of Ahr in the hematopoietic compartment was important for accumulation of adult but not fetal intestinal RORγt(+) ILCs. Without Ahr, RORγt(+) ILCs had increased apoptosis and less production of IL-22. RORγt interacted with Ahr and promoted Ahr binding at the Il22 locus. Upon IL-23 stimulation, Ahr-deficient RORγt(+) ILCs had reduced IL-22 expression, consistent with downregulation of IL-23R in those cells. Ahr-deficient mice succumbed to Citrobacter rodentium infection, whereas ectopic expression of IL-22 protected animals from early mortality. Our data uncover a previously unrecognized physiological role for Ahr in promoting innate gut immunity by regulating RORγt(+) ILCs.
PMID: 22177117 [PubMed - as supplied by publisher]
Th17 Cells Are Long Lived and Retain a Stem Cell-like Molecular Signature.
Immunity. 2011 Dec 23;35(6):972-85
Authors: Muranski P, Borman ZA, Kerkar SP, Klebanoff CA, Ji Y, Sanchez-Perez L, Sukumar M, Reger RN, Yu Z, Kern SJ, Roychoudhuri R, Ferreyra GA, Shen W, Durum SK, Feigenbaum L, Palmer DC, Antony PA, Chan CC, Laurence A, Danner RL, Gattinoni L, Restifo NP
Abstract
Th17 cells have been described as short lived, but this view is at odds with their capacity to trigger protracted damage to normal and transformed tissues. We report that Th17 cells, despite displaying low expression of CD27 and other phenotypic markers of terminal differentiation, efficiently eradicated tumors and caused autoimmunity, were long lived, and maintained a core molecular signature resembling early memory CD8(+) cells with stem cell-like properties. In addition, we found that Th17 cells had high expression of Tcf7, a direct target of the Wnt and β-catenin signaling axis, and accumulated β-catenin, a feature observed in stem cells. In vivo, Th17 cells gave rise to Th1-like effector cell progeny and also self-renewed and persisted as IL-17A-secreting cells. Multipotency was required for Th17 cell-mediated tumor eradication because effector cells deficient in IFN-γ or IL-17A had impaired activity. Thus, Th17 cells are not always short lived and are a less-differentiated subset capable of superior persistence and functionality.
PMID: 22177921 [PubMed - in process]
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