bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chronically Inflamed Human Tissues Are Infiltrated by Highly Differentiated Th17 Lymphocytes
Authors: Pène Jérôme , Chevalier Sylvie , Preisser Laurence , Vénéreau Emilie , Guilleux Marie-Hélène , Ghannam Soufiane , Molès Jean-Pierre , Danger Yannic , Ravon Elisa , Lesaux Sabine , Yssel Hans , Gascan Hugues 
Published: April 2014

Abstract
Chronic inflammatory diseases are characterized by local tissue injury caused by immunocompetent cells, in particular CD4+ T lymphocytes, that are involved in the pathogenesis of these disorders via the production of distinctive sets of cytokines. Here, we have characterized single CD4+ T cells that infiltrate inflamed tissue taken from patients with psoriasis, Crohn’s disease, rheumatoid arthritis, or allergic asthma. Results from a cytokine production and gene profile analysis identified a population of in vivo differentiatedretinoid-related orphan receptor γ-expressing T cells, producing high levels of IL-17, that can represent up to 30% of infiltrating T lymphocytes. Activated Th17 cells produced IL-26, TNF-α, lymphotoxin-β, and IL-22. IL-17 and IL-22 concentrations secreted by tissue infiltrating Th17 cells could reach up to 100 nM and were inversely correlated with the production of Th1- and Th2-associated cytokines. In addition, tissue-infiltrating Th17 cells are also characterized by high cell surface expression of CCR6, a chemokine receptor that was not expressed by Th1 and Th2 cells, isolated from the same lesions, and by the production of CCL20/MIP3α, a CCR6 ligand, associated with tissue infiltration. Culture supernatants of activated Th17 cells, isolated from psoriatic lesions, induced the expression of gene products associated with inflammation and abnormal keratinocyte differentiation in an IL-17 and IL-22-dependent manner. These results show that tissue-infiltrating Th17 cells contribute to human chronic inflammatory disease via the production of several inflammatory cytokines and the creation of an environment contributing to their migration and sequestration at sites of inflammation.
Differential Expression of the Human CD8β Splice Variants and Regulation of the M-2 Isoform by Ubiquitination
Authors: Thakral Deepshi , Dobbins Jessica , Devine Lesley , Kavathas Paula B. 
Published: April 2014

Abstract
The CD8αβ heterodimer functions as a coreceptor with the TCR, influencing the outcome of CD8+ T cell responses to pathogen-infected and tumor cells. In contrast to the murine CD8B gene, the human gene encodes alternatively spliced variants with different cytoplasmic tails (M-1, M-2, M-3, and M-4). At present, little is known about the expression patterns and functional significance of such variants. We used quantitative RT-PCR to demonstrate differential mRNA expression patterns of these splice variants in thymocytes and in resting, memory, and activated primary human CD8+ T cells. In total CD8+ T cells, mRNA levels of the M-1 variant were the most predominant and levels of M-3 were the least detected. The M-4 isoform was predominant in effector memory CD8+ T cells. Upon stimulation of CD8+ T cells, the M-2 variant mRNA levels were elevated 10–20-fold relative to resting cells in contrast to the other isoforms. Curiously, the M-2 isoform was not expressed on the cell surface in transfected cell lines. Using fluorescent chimeras of the extracellular domain of mouse CD8β fused to the cytoplasmic tails of each isoform, the M-2 isoform was localized in a lysosomal compartment regulated by ubiquitination of a lysine residue (K215) in its cytoplasmic tail. In contrast, upon short-term stimulation, the M-2 protein localized to the cell surface with the TCR complex. The relatively recent evolution of CD8B gene splice variants in the chimpanzee/human lineage is most likely important for fine-tuning the CD8+ T cell responses.
Leishmania braziliensis Infection Induces Dendritic Cell Activation, ISG15 Transcription, and the Generation of Protective Immune Responses
Authors: Vargas-Inchaustegui Diego A. , Xin Lijun , Soong Lynn 
Published: April 2014

Abstract
Leishmania (Viannia) braziliensis is the causative agent of cutaneous and mucosal leishmaniasis in South America, and the latter is a severe and disfiguring form of the disease. Our understanding of how L. braziliensis parasites interact with dendritic cells (DCs) is limited, partially due to the difficulty in generating axenic amastigotes. In this study, we successfully generated axenic amastigotes of L. braziliensis and used them to test the hypothesis that L. braziliensis infection efficiently triggers innate responses in DCs and the subsequent adaptive immune responses for parasite clearance. This study has revealed unique immunological features of L. braziliensis infection. Firstly, axenic amastigotes showed higher infectivity and the potential to stimulate C57BL/6 (B6) bone marrow-derived dendritic cells to produce IL-12p40 when compared with their promastigote counterparts. Both parasite-carrying and bystander DCs displayed an activated (CD11chighCD45RB−CD83+CD40+CD80+) phenotype. Secondly, L. braziliensis infection triggered transcription and phosphorylation of STAT molecules and IFN-stimulated gene 15 (ISG15). Finally, the self-healing of the infection in mice was correlated to the expansion of IFN-γ- and IL-17-producing CD4+ cells, suggesting the existence of active mechanisms to regulate local inflammation. Collectively, this study supports the view that innate responses at the DC level determine parasite-specific T cell responses and disease outcomes.
Mast Cell Cathelicidin Antimicrobial Peptide Prevents Invasive Group A Streptococcus Infection of the Skin
Authors: Di Nardo Anna , Yamasaki Kenshi , Dorschner Robert A. , Lai Yuping , Gallo Richard L. 
Published: April 2014

Abstract
Mast cells (MC) express cathelicidin antimicrobial peptides that act as broad-spectrum antibiotics and influence the immune defense of multiple epithelial surfaces. We hypothesized that MC help protect against skin infection through the expression of cathelicidin. The susceptibility of MC-deficient mice (Kit Wsh−/−) to invasive group A streptococcus (GAS) was compared with control mice. Following s.c. injection of GAS, MC-deficient mice had 30% larger skin lesions, 80% more lesional bacteria, and 30% more spleens positive for bacteria. In contrast to results obtained when GAS was injected into skin, no significant differences were noted between MC-deficient mice and control mice after GAS was applied topically, indicating that MC activity is most important after barrier penetration. To determine whether these differences were due to MC expression of cathelicidin, MC-deficient mice were reconstituted with MC derived from either wild-type or cathelicidin-deficient (Camp−/−) mice and challenged with GAS. Forty-eight hours after bacterial injection, mice that did not receive MC had an average lesion size of 200 mm2, mice reconstituted with wild-type MC showed lesions comparable to control mice (25 mm2), while mice reconstituted with Camp−/− MC showed an average lesion size of 120 mm2. Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) analysis of cathelicidin peptide purified from mast cells defined this as a unique 28-aa peptide. Combined, these results show that MC confer defense against Gram-positive bacterial infection in the skin, a function mediated in part by the expression of a unique cathelicidin peptide.
Activity of Adenosine Receptors Type 1 Is Required for CX3CL1-Mediated Neuroprotection and Neuromodulation in Hippocampal Neurons
Authors: Lauro Clotilde , Di Angelantonio Silvia , Cipriani Raffaela , Sobrero Fabrizia , Antonilli Letizia , Brusadin Valentina , Ragozzino Davide , Limatola Cristina 
Published: April 2014

Abstract
The chemokine fractalkine (CX3CL1) is constitutively expressed by central neurons, regulating microglial responses including chemotaxis, activation, and toxicity. Through the activation of its own specific receptor, CX3CR1, CX3CL1 exerts both neuroprotection against glutamate (Glu) toxicity and neuromodulation of the glutamatergic synaptic transmission in hippocampal neurons. Using cultured hippocampal neuronal cell preparations, obtained from CX3CR1−/− (CX3CR1GFP/GFP) mice, we report that these same effects are mimicked by exposing neurons to a medium conditioned with CX3CL1-treated mouse microglial cell line BV2 (BV2-st medium). Furthermore, CX3CL1-induced neuroprotection from Glu toxicity is mediated through the adenosine receptor 1 (AR1), being blocked by neuronal cell preparations treatment with 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), a specific inhibitor of AR1, and mimicked by both adenosine and the specific AR1 agonist 2-chloro-N6-cyclopentyladenosine. Similarly, experiments from whole-cell patch-clamped hippocampal neurons in culture, obtained from CX3CR1+/+ mice, show that CX3CL1-induced depression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid- (AMPA-) type Glu receptor-mediated current (AMPA-current), is associated with AR1 activity being blocked by DPCPX and mimicked by adenosine. Furthermore, BV2-st medium induced a similar AMPA-current depression in CX3CR1GFP/GFP hippocampal neurons and this depression was again blocked by DPCPX. We also report that CX3CL1 induced a significant release of adenosine from microglial BV2 cells, as measured by HPLC analysis. We demonstrate that (i) CX3CL1, along with AR1, are critical players for counteracting Glu-mediated neurotoxicity in the brain and (ii) AR1 mediates neuromodulatory action of CX3CL1 on hippocampal neurons.
IL-10 Inhibits Cysteinyl Leukotriene-Induced Activation of Human Monocytes and Monocyte-Derived Dendritic Cells
Authors: Woszczek Grzegorz , Chen Li-Yuan , Nagineni Sahrudaya , Shelhamer James H. 
Published: April 2014

Abstract
The immunoregulatory cytokine IL-10 plays an essential role in down-modulating adaptive and innate immune responses leading to chronic inflammatory diseases. In contrast, cysteinyl leukotrienes (cysLTs), important proinflammatory mediators of cell trafficking and innate immune responses, are thought to enhance immune reactions in the pathogenesis of diseases, such as bronchial asthma, atherosclerosis, and pulmonary fibrosis. The aim of this study was to determine the IL-10 regulatory role in cysLT-induced activation of human monocytes and monocyte-derived dendritic cells. Herein we show that cysLT-induced activation and chemotaxis of human monocytes and monocyte-derived immature dendritic cells (iDC) are inhibited by IL-10 pretreatment. IL-10 down-regulated cysLT type 1 and 2 receptors’ mRNA in a time- and concentration-dependent fashion. cysLT-induced activation of monocytes and iDCs measured by intracellular calcium flux and immediate-early gene expression (FBJ murine osteosarcoma viral oncogen homolog B and early growth response-2) was potently decreased by IL-10 and by the cysLT antagonist MK571. Chemotaxis of monocytes and iDCs to increasing concentrations of leukotriene D4 (LTD4) was also inhibited by IL-10. LTD4 enhanced iDC migration in response to CCL5. IL-10 selectively inhibited LTD4-induced chemotaxis without affecting migration to CCL5. These data indicate that cysLT-induced activation of human monocytes and dendritic cells may be specifically inhibited by IL-10, suggesting a direct link between the 5-lipoxygenase proinflammatory pathway and IL-10 regulatory mechanisms. Antileukotriene therapies may reproduce some regulatory mechanisms played by IL-10 in inflammatory processes.
Analysis of the Neuroinflammatory Response to TLR7 Stimulation in the Brain: Comparison of Multiple TLR7 and/or TLR8 Agonists
Authors: Butchi Niranjan B. , Pourciau Susan , Du Min , Morgan Tim W. , Peterson Karin E. 
Published: April 2014

Abstract
Activation of astrocytes and microglia and the production of proinflammatory cytokines and chemokines are often associated with virus infection in the CNS as well as a number of neurological diseases of unknown etiology. These inflammatory responses may be initiated by recognition of pathogen-associated molecular patterns (PAMPs) that stimulate TLRs. TLR7 and TLR8 were identified as eliciting antiviral effects when stimulated by viral ssRNA. In the present study, we examined the potential of TLR7 and/or TLR8 agonists to induce glial activation and neuroinflammation in the CNS by intracerebroventricular inoculation of TLR7 and/or TLR8 agonists in newborn mice. The TLR7 agonist imiquimod induced astrocyte activation and up-regulation of proinflammatory cytokines and chemokines, including IFN-β, TNF, CCL2, and CXCL10. However, these responses were only of short duration when compared with responses induced by the TLR4 agonist LPS. Interestingly, some of the TLR7 and/or TLR8 agonists differed in their ability to activate glial cells as evidenced by their ability to induce cytokine and chemokine expression both in vivo and in vitro. Thus, TLR7 stimulation can induce neuroinflammatory responses in the brain, but individual TLR7 agonists may differ in their ability to stimulate cells of the CNS.
Suppressive Oligodeoxynucleotides Inhibit Silica-Induced Pulmonary Inflammation
Authors: Sato Takashi , Shimosato Takeshi , Alvord W. Gregory , Klinman Dennis M. 
Published: April 2014

Abstract
Inhalation of silica-containing dust particles induces silicosis, an inflammatory disease of the lungs characterized by the infiltration of macrophages and neutrophils into the lungs and the production of proinflammatory cytokines, chemokines, and reactive oxygen species (ROS). Synthetic oligodeoxynucleotides (ODN) expressing “immunosuppressive motifs” were recently shown to block pathologic inflammatory reactions in murine models of autoimmune disease. Based on those findings, the potential of suppressive ODN to prevent acute murine silicosis was examined. In vitro studies indicate that suppressive ODN blunt silica-induced macrophage toxicity. This effect was associated with a reduction in ROS production and p47phox expression (a subunit of NADPH oxidase key to ROS generation). In vivo studies show that pretreatment with suppressive (but not control) ODN reduces silica-dependent pulmonary inflammation, as manifest by fewer infiltrating cells, less cytokine/chemokine production, and lower levels of ROS (p &lt; 0.01 for all parameters). Treatment with suppressive ODN also reduced disease severity and improved the survival (p &lt; 0.05) of mice exposed to silica.
Dependency of Caspase-1 Activation Induced in Macrophages by Listeria monocytogenes on Cytolysin, Listeriolysin O, after Evasion from Phagosome into the Cytoplasm
Authors: Hara Hideki , Tsuchiya Kohsuke , Nomura Takamasa , Kawamura Ikuo , Shoma Shereen , Mitsuyama Masao 
Published: April 2014

Abstract
Listeriolysin O (LLO), an hly-encoded cytolysin from Listeria monocytogenes, plays an essential role in the entry of this pathogen into the macrophage cytoplasm and is also a key factor in inducing the production of IFN-γ during the innate immune stage of infection. In this study, we examined the involvement of LLO in macrophage production of the IFN-γ-inducing cytokines IL-12 and IL-18. Significant levels of IL-12 and IL-18 were produced by macrophages upon infection with wild-type L. monocytogenes, whereas an LLO-deficient mutant (the L. monocytogenes Δhly) lacked the ability to induce IL-18 production. Complementation of Δhly with hly completely restored the ability. However, when Δhly was complemented with ilo encoding ivanolysin O (ILO), a cytolysin highly homologous with LLO, such a restoration was not observed, although ILO-expressing L. monocytogenes invaded and multiplied in the macrophage cytoplasm similarly as LLO-expressing L. monocytogenes. Induction of IL-18 was diminished when pretreated with a caspase-1 inhibitor or in macrophages from caspase-1-deficient mice, suggesting the activation of caspase-1 as a key event resulting in IL-18 production. Activation of caspase-1 was induced in macrophages infected with LLO-expressing L. monocytogenes but not in those with Δhly. A complete restoration of such an activity could not be observed even after complementation with the ILO gene. These results show that the LLO molecule is involved in the activation of caspase-1, which is essential for IL-18 production in infected macrophages, and suggest that some sequence unique to LLO is indispensable for some signaling event resulting in the caspase-1 activation induced by L. monocytogenes.
The Tec Family Kinase, IL-2-Inducible T Cell Kinase, Differentially Controls Mast Cell Responses
Authors: Iyer Archana S. , August Avery 
Published: April 2014

AbstractThe Tec family tyrosine kinase, IL-2-inducible T cell kinase (Itk), is expressed in T cells and mast cells. Mice lacking Itk exhibit impaired Th2 cytokine secretion; however, they have increased circulating serum IgE, but exhibit few immunological symptoms of allergic airway responses. We have examined the role of Itk in mast cell function and FcεRI signaling. We report in this study that Itk null mice have reduced allergen/IgE-induced histamine release, as well as early airway hyperresponsiveness in vivo. This is due to the increased levels of IgE in the serum of these mice, because the transfer of Itk null bone marrow-derived cultured mast cells into mast cell-deficient W/Wv animals is able to fully rescue histamine release in the W/Wv mice. Further analysis of Itk null bone marrow-derived cultured mast cells in vitro revealed that whereas they have normal degranulation responses, they secrete elevated levels of cytokines, including IL-13 and TNF-α, particularly in response to unliganded IgE. Analysis of biochemical events downstream of the FcεRI revealed little difference in overall tyrosine phosphorylation of specific substrates or calcium responses; however, these cells express elevated levels of NFAT, which was largely nuclear. Our results suggest that the reduced mast cell response in vivo in Itk null mice is due to elevated levels of IgE in these mice. Our results also suggest that Itk differentially modulates mast cell degranulation and cytokine production in part by regulating expression and activation of NFAT proteins in these cells.
Th2 Differentiation Is Unaffected by Jagged2 Expression on Dendritic Cells
Authors: Krawczyk Connie M. , Sun Jie , Pearce Edward J. 
Published: April 2014

Abstract
Expression of the Jagged Notch ligands by dendritic cells (DCs) has been suggested to play a role in instructing Th2 responses. Supporting this hypothesis, we found that Jagged2 but not Jagged1 expression, correlates with the ability of DCs to induce Th2 responses. Jagged2 expression is up-regulated in response to the helminth soluble Schistosoma mansoni egg Ag, which conditions DCs to induce Th2 responses, and is markedly down-regulated following exposure to TLR agonists that generally promote Th1 responses. Conversely, Jagged1 expression is markedly induced by TLR ligation. Despite these correlations, suppression of expression of Jagged2 using retrovirally delivered small interfering RNA failed to affect the ability of DCs to induce Th2 cell differentiation either in vitro or in vivo. Moreover, retrovirally induced expression of Jagged2 did not enhance the ability of DCs to induce Th2 cell responses. Our data indicate that Jagged2 expression by DCs is not sufficient or required for Th2 cell differentiation.
Homogenization of TCR Repertoires within Secondary CD62Lhigh and CD62Llow Virus-Specific CD8+ T Cell Populations
Authors: Kedzierska Katherine , Venturi Vanessa , Valkenburg Sophie A. , Davenport Miles P. , Turner Stephen J. , Doherty Peter C. 
Published: April 2014

Abstract
Influenza virus-specific CD8+ T cell clonotypes generated and maintained in C57BL/6J mice after respiratory challenge were found previously to distribute unequally between the CD62Llow “effector” (TEM) and CD62Lhigh “central” (TCM) memory subsets. Defined by the CDR3β sequence, most of the prominent TCRs were represented in both the CD62Lhigh and CD62Llow subsets, but there was also a substantial number of diverse, but generally small, CD62Lhigh-only clonotypes. The question asked here is how secondary challenge influences both the diversity and the continuity of TCR representation in the TCM and TEM subsets generated following primary exposure. The experiments use single-cell RT-PCR to correlate clonotypic composition with CD62L phenotype for secondary influenza-specific CD8+ T cell responses directed at the prominent DbNP366 and DbPA224 epitopes. In both the acute and long-term memory phases of the recall responses to these epitopes, we found evidence of a convergence of TCR repertoire expression for the CD62Llow and CD62Lhigh populations. In fact, unlike the primary response, there were no significant differences in clonotypic diversity between the CD62Llow and CD62Lhigh subsets. This “TCR homogenization” for the CD62Lhigh and CD62Llow CD8+ populations recalled after secondary challenge indicates common origin, most likely from the high prevalence populations in the CD62Lhigh central memory set. Our study thus provides key insights into the TCR diversity spectrum for CD62Lhigh and CD62Llow T cells generated from a normal, unmanipulated T cell repertoire following secondary challenge. A better understanding of TCR selection and maintenance has implications for improved vaccine and immunotherapy protocols.
Therapeutic Vaccination with Simian Immunodeficiency Virus (SIV)-DNA+IL-12 or IL-15 Induces Distinct CD8 Memory Subsets in SIV-Infected Macaques
Authors: Halwani Rabih , Boyer Jean D. , Yassine-Diab Bader , Haddad Elias K. , Robinson Tara M. , Kumar Sanjeev , Parkinson Rose , Wu Ling , Sidhu Maninder K. , Phillipson-Weiner Rebecca , Pavlakis George N. , Felber Barbara K. , Lewis Mark G. , Shen Anding , Siliciano Robert F. , Weiner David B. , Sekaly Rafick-Pierre 
Published: April 2014

AbstractDNA vaccination is an invaluable approach for immune therapy in that it lacks vector interference and thus permits repeated vaccination boosts. However, by themselves, DNA-based vaccines are typically poor inducers of Ag-specific immunity in humans and non-human primates. Cytokines, such as IL-12 and IL-15, have been shown to be potent adjuvants for the induction and maintenance of cellular immune responses, in particular during HIV infection. In this study, we examined the ability of therapeutic vaccination with SIV-DNA+IL-12 or IL-15 as molecular adjuvants to improve DNA vaccine potency and to enhance memory immune responses in SIV-infected macaques. Our results demonstrate that incorporating IL-12 into the vaccine induces SIV-specific CD8 effector memory T cell (TEM) functional responses and enhances the capacity of IFN-γ-producing CD8 TEM cells to produce TNF. Lower levels of PD-1 were expressed on T cells acquiring dual function upon vaccination as compared with mono-functional CD8 TEM cells. Finally, a boost with SIV-DNA+IL-15 triggered most T cell memory subsets in macaques primed with either DNA-SIV or placebo but only CD8 TEM in macaques primed with SIV-DNA+IL-12. These results indicate that plasmid IL-12 and IL-15 cytokines represent a significant addition to enhance the ability of therapeutic DNA vaccines to induce better immunity.