bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preferential Apoptosis of HIV-1-Specific CD4+ T Cells
Authors: Yue Feng Yun , Kovacs Colin M. , Dimayuga Rowena C. , Gu Xiao Xiao Jenny , Parks Paul , Kaul Rupert , Ostrowski Mario A. 
Published: April 2014

Abstract
In contrast to other viral infections such as CMV, circulating frequencies of HIV-1-specific CD4+ T cells in peripheral blood are quantitatively diminished in the majority of HIV-1-infected individuals. One mechanism for this quantitative defect is preferential infection of HIV-1-specific CD4+ T cells, although &lt;10% of HIV-1-specific CD4+ T cells are infected. Apoptosis has been proposed as an important contributor to the pathogenesis of CD4+ T cell depletion in HIV/AIDS. We show here that, within HIV-1-infected individuals, a greater proportion of ex vivo HIV-1-specific CD4+ T cells undergo apoptosis compared with CMV-specific CD4+ T cells (45 vs 7.4%, respectively, p &lt; 0.05, in chronic progressors). The degree of apoptosis within HIV-1-specific CD4+ T cells correlates with viral load and disease progression, and highly active antiretroviral therapy abrogates these differences. The data support a mechanism for apoptosis in these cells similar to that found in activation-induced apoptosis through the TCR, resulting in oxygen-free radical production, mitochondrial damage, and caspase-9 activation. That HIV-1 proteins can also directly enhance activation-induced apoptosis supports a mechanism for a preferential induction of apoptosis of HIV-1-specific CD4+ T cells, which contributes to a loss of immunological control of HIV-1 replication.
IL-2 and Autocrine IL-4 Drive the In Vivo Development of Antigen-Specific Th2 T Cells Elicited by Nematode Parasites
Authors: Liu Zhugong , Liu Qian , Hamed Hossein , Anthony Robert M. , Foster Anthony , Finkelman Fred D. , Urban Joseph F. , Gause William C. 
Published: April 2014

Abstract
The intestinal nematode parasite, Nippostrongylus brasiliensis, triggers potent type 2 immunity. Using OVA peptide as a model Ag, we have examined the adjuvant effects of this parasite on the in vivo development of Ag-specific Th2 cells from naive DO11.10 T cells. Our findings show that Th2 cells can develop from transferred naive OVA-specific DO11.10 T cells in recipient IL-4−/− mice inoculated with N. brasiliensis plus OVA. However, autocrine IL-4 is required for in situ Th2 cell differentiation since transferred IL-4Rα-deficient DO11.10 T cells showed greatly reduced Th2 cell development in inoculated IL-4−/− recipient mice. Surprisingly, we also found that IL-2 blockade promoted B7-dependent T cell cycling, but inhibited the development of OVA-specific Th2 cells. Furthermore, the effects of IL-2 occurred independently of CD25+ T regulatory cells. These studies establish a previously unrecognized requirement for autocrine IL-4 and IL-2 in Th2 responses elicited by nematode parasites.
Potentiation of Glucocorticoid Activity in Hypoxia through Induction of the Glucocorticoid Receptor
Authors: Leonard Martin O. , Godson Catherine , Brady Hugh R. , Taylor Cormac T. 
Published: April 2014

Abstract
Tissue hypoxia is intimately associated with chronic inflammatory disease and may signal to the resolution of inflammatory processes. Glucocorticoid signaling through the glucocorticoid receptor (GR) represents a clinically important endogenous anti-inflammatory pathway. Microarray analysis reveals that the GR is transcriptionally up-regulated by hypoxia in human renal proximal tubular epithelial cells. Hypoxic up-regulation of the GR was confirmed at the level of promoter activity, mRNA, and protein expression. Furthermore, functional potentiation of glucocorticoid activity in hypoxia was observed as an enhancement of dexamethasone-induced glucocorticoid response element promoter activity and enhanced dexamethasone-mediated inhibition of IL-1β-stimulated IL-8 expression and hypoxia-induced vascular endothelial growth factor expression. Knockdown of enhanced GR gene expression in hypoxia using specific GR small inhibitory RNA (siRNA) resulted in an attenuation of the enhanced glucocorticoid sensitivity. A role for the hypoxia-inducible transcription factor, HIF-1α, in the regulation of GR expression and the associated potentiation of glucocorticoid activity in hypoxia was also demonstrated. These results reveal a novel signaling aspect responsible for the incorporation of hypoxic and glucocorticoid stimuli, which we hypothesize to be an important co-operative pathway for the control of gene expression observed in complex tissue microenvironments in inflamed states.
Multiple β1 Integrins Mediate Enhancement of Human Airway Smooth Muscle Cytokine Secretion by Fibronectin and Type I Collagen
Authors: Peng Qi , Lai Dilys , Nguyen Trang T.-B. , Chan Vivien , Matsuda Takeshi , Hirst Stuart J. 
Published: April 2014

AbstractAltered airway smooth muscle (ASM) function and enrichment of the extracellular matrix (ECM) with interstitial collagen and fibronectin are major pathological features of airway remodeling in asthma. We have previously shown that these ECM components confer enhanced ASM proliferation in vitro, but their action on its newly characterized secretory function is unknown. Here, we examined the effects of fibronectin and collagen types I, III, and V on IL-1β-dependent secretory responses of human ASM cells, and characterized the involvement of specific integrins. Cytokine production (eotaxin, RANTES, and GM-CSF) was evaluated by ELISA, RT-PCR, and flow cytometry. Function-blocking integrin mAbs and RGD (Arg-Gly-Asp)-blocking peptides were used to identify integrin involvement. IL-1β-dependent release of eotaxin, RANTES, and GM-CSF was enhanced by fibronectin and by fibrillar and monomeric type I collagen, with similar changes in mRNA abundance. Collagen types III and V had no effect on eotaxin or RANTES release but did modulate GM-CSF. Analogous changes in intracellular cytokine accumulation were found, but in &lt;25% of the total ASM cell population. Function-blocking Ab and RGD peptide studies revealed that α2β1, α5β1, αvβ1, and αvβ3 integrins were required for up-regulation of IL-1β-dependent ASM secretory responses by fibronectin, while α2β1 was an important transducer for type I collagen. Thus, fibronectin and type I collagen enhance IL-1β-dependent ASM secretory responses through a β1 integrin-dependent mechanism. Enhancement of cytokine release from ASM by these ECM components may contribute to airway wall inflammation and remodeling in asthma.
Heparin Binds to Lipopolysaccharide (LPS)-Binding Protein, Facilitates the Transfer of LPS to CD14, and Enhances LPS-Induced Activation of Peripheral Blood Monocytes
Authors: Heinzelmann Michael , Bosshart Herbert 
Published: April 2014

AbstractHeparin is one of the most effective drugs for preventing and treating thromboembolic complications in surgical patients. Recent evidence suggests that heparin enhances the proinflammatory responses of human peripheral blood monocytes to Gram-negative endotoxin (LPS). We have identified LPS-binding protein (LBP) as a novel heparin-binding plasma protein. The affinity of LPB to heparin was KD = 55 ± 8 nM, as measured by surface plasmon resonance. Using a fluorescence-based assay, we showed that clinically used heparin preparations significantly enhance the ability of LBP to catalytically disaggregate and transfer LPS to CD14, the LPS receptor. The presence of clinically relevant heparin concentrations in human whole blood increased LPS-induced production of the proinflammatory cytokine IL-8. Fondaparinux, which is identical with the antithrombin III-binding pentasaccharide in heparin, did not bind to LBP or alter LBP function. Thus, this novel anticoagulant drug is a potential candidate for safe administration to patients who have endotoxemia and require anticoagulation.
IL-11 Receptor α in the Pathogenesis of IL-13-Induced Inflammation and Remodeling
Authors: Chen Qingsheng , Rabach Lesley , Noble Paul , Zheng Tao , Lee Chun Geun , Homer Robert J. , Elias Jack A. 
Published: April 2014

AbstractIL-13 is a major stimulator of inflammation and tissue remodeling at sites of Th2 inflammation. In Th2-dominant inflammatory disorders such as asthma, IL-11 is simultaneously induced. However, the relationship(s) between IL-11 and IL-13 in these responses has not been defined, and the role(s) of IL-11 in the genesis of the tissue effects of IL-13 has not been evaluated. We hypothesized that IL-11, signaling via the IL-11Rα-gp130 receptor complex, plays a key role in IL-13-induced tissue responses. To test this hypothesis we compared the expression of IL-11, IL-11Rα, and gp130 in lungs from wild-type mice and transgenic mice in which IL-13 was overexpressed in a lung-specific fashion. We simultaneously characterized the effects of a null mutation of IL-11Rα on the tissue effects of transgenic IL-13. These studies demonstrate that IL-13 is a potent stimulator of IL-11 and IL-11Rα. They also demonstrate that IL-13 is a potent stimulator of inflammation, fibrosis, hyaluronic acid accumulation, myofibroblast accumulation, alveolar remodeling, mucus metaplasia, and respiratory failure and death in mice with wild-type IL-11Rα loci and that these alterations are ameliorated in the absence of IL-11Rα. Lastly, they provide insight into the mechanisms of these processes by demonstrating that IL-13 stimulates CC chemokines, matrix metalloproteinases, mucin genes, and gob-5 and stimulates and activates TGF-β1 via IL-11Rα-dependent pathways. When viewed in combination, these studies demonstrate that IL-11Rα plays a key role in the pathogenesis of IL-13-induced inflammation and remodeling.
In Vitro Engagement of CD3 and CD28 Corrects T Cell Defects in Chronic Lymphocytic Leukemia
Authors: Bonyhadi Mark , Frohlich Mark , Rasmussen Angela , Ferrand Christophe , Grosmaire Laura , Robinet Eric , Leis Jose , Maziarz Richard T. , Tiberghien Pierre , Berenson Ronald J. 
Published: April 2014

Abstract
Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of leukemic B cells concomitant with immunological abnormalities and depressed immune responses. The T cell abnormalities found in CLL patients are thought to increase the risk of infection and hamper immune recognition and elimination of leukemic cells. We evaluated whether providing signals through CD3 and CD28 would correct some of these T cell defects. PBMC were incubated with anti-CD3 and anti-CD28 mAbs conjugated to superparamagnetic beads for 12–14 days. This resulted in a 1400-fold increase in T cell numbers. Activated T cells expressed high levels of CD25, CD54, CD137, and CD154, and produced IFN-γ, TNF-α, and GM-CSF. The mean T cell composition of cultures increased from ∼6% to &gt;90% and leukemic B cells decreased from a mean of ∼85% to 0.1% or less. Leukemic B cells up-regulated expression of CD54, CD80, CD86, and CD95. Receptor up-regulation required direct cell contact with the activated T cells and could be blocked with anti-CD154 mAb, suggesting that the CD40-CD40L pathway helped mediate these effects. Poor T cell responses to allostimulation were corrected by the activation and expansion process. The skewing in the TCR repertoire returned to normal, or near normal following the culture process in eight of nine patients with abnormal TCR repertoires. Activated T cells had potent in vitro antileukemic effects in contrast to nonactivated T cells. Based upon these findings, a clinical trial has been initiated to test the potential therapeutic effects of T cells activated using this approach in patients with CLL.
Middle-Age Male Mice Have Increased Severity of Experimental Autoimmune Encephalomyelitis and Are Unresponsive to Testosterone Therapy
Authors: Matejuk Agata , Hopke Corwyn , Vandenbark Arthur A. , Hurn Patricia D. , Offner Halina 
Published: April 2014

Abstract
Treatment with sex hormones is known to protect against experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. However, little is known about how age affects the course of EAE or response to hormone treatment. This study demonstrates striking differences between middle-age vs young C57BL/6 male mice in the clinical course of EAE and response to both testosterone (T4) and estrogen (E2) hormone therapy. Unlike young males that developed an acute phase of EAE followed by a partial remission, middle-age males suffered severe chronic and unremitting EAE that was likely influenced by alterations in the distribution and function of splenic immunocytes and a significant reduction in suppressive activity of CD4+CD25+ regulatory T cells in the spleen and spinal cord. Middle-age males had reduced numbers of splenic CD4+ T cells that were generally hypoproliferative, but enhanced numbers of splenic macrophages and MHC class II-expressing cells, and increased secretion of the proinflammatory factors IFN-γ and MCP-1. Surprisingly, middle-age males were unresponsive to the EAE-protective effects of T4 and had only a transient benefit from E2 treatment; young males were almost completely protected by both hormone treatments. T4 treatment of young males inhibited proliferation of myelin oligodendrocyte glycoprotein 35–55-specific T cells and secretion of TNF-α and IFN-γ. The effects of T4 in vivo and in vitro were reversed by the androgen receptor antagonist, flutamide, indicating that the regulatory effects of T4 were mediated through the androgen receptor. These data are the first to define age-dependent differences in EAE expression and response to hormone therapy.
Monitoring of Anti-Vaccine CD4 T Cell Frequencies in Melanoma Patients Vaccinated with a MAGE-3 Protein
Authors: Zhang Yi , Sun Zhaojun , Nicolay Hugues , Meyer Ralf G. , Renkvist Nicolina , Stroobant Vincent , Corthals Jurgen , Carrasco Javier , Eggermont Alexander M. M. , Marchand Marie , Thielemans Kris , Wölfel Thomas , Boon Thierry , van der Bruggen Pierre 
Published: April 2014

Abstract
Quantitative evaluation of T cell responses of patients receiving antitumoral vaccination with a protein is difficult because of the large number of possible HLA-peptide combinations that could be targeted by the response. To evaluate the responses of patients vaccinated with protein MAGE-3, we have developed an approach that involves overnight stimulation of blood T cells with autologous dendritic cells loaded with the protein, sorting by flow cytometry of the T cells that produce IFN-γ, cloning of these cells, and evaluation of the number of T cell clones that secrete IFN-γ upon stimulation with the Ag. An important criterion is that T cell clones must recognize not only stimulator cells loaded with the protein, but also stimulator cells transduced with the MAGE-3 gene, so as to exclude the T cells that recognize contaminants generated by the protein production system. Using this approach it is possible to measure T cell frequencies as low as 10−6. We analyzed the frequencies of anti-vaccine CD4 T cells in five metastatic melanoma patients who had been injected with a MAGE-3 protein without adjuvant and showed evidence of tumor regression. Anti-MAGE-3 CD4 T cells were detected in one of the five patients. The frequency of the anti-MAGE-3 CD4 T cells was estimated at 1/60,000 of the CD4 T cells in postvaccination blood samples, representing at least an 80-fold increase in the frequency found before immunization. The frequencies of one anti-MAGE-3 CD4 T cell clonotype were confirmed by PCR analysis on blood lymphocytes. The 13 anti-MAGE-3 clones, which corresponded to five different TCR clonotypes, recognized the same peptide presented by HLA-DR1.
Activation of Marginal Zone B Cells from Lupus Mice with Type A(D) CpG-Oligodeoxynucleotides
Authors: Brummel Rachel , Lenert Petar 
Published: April 2014

Abstract
Several types of CpG-oligodeoxynucleotides (ODN) have been recently characterized. In mice, type A(D) CpG-ODNs primarily stimulate macrophages and dendritic cells, but fail to stimulate B cells. On the contrary, type B(K) CpG-ODNs are excellent B cell activators. Type C CpG-ODNs combine features of both types A(D) and B(K) CpG-ODNs. Despite cell type preferences, all CpG-ODNs require the presence of TLR9 for activation. In this study, we show that a subset of B cells from lupus mice responds to type A(D) CpG-ODN stimulation vigorously and directly with increased CD25 and CD86 expression and IL-10 secretion. Furthermore, these CpG-ODNs induce high surface IgM expression and promote 50- to 100-fold higher IgM and IgG3 secretion in lupus B cells than in controls. This response is similar to that seen with bacterial DNA stimulation of B cells. Type A(D)-responsive cells are enriched within lupus B cells with the marginal zone (MZ) phenotype. These cells are at least twice more numerous in lupus mice than in controls. The ability of lupus B cells to respond to type A(D) CpG-ODN stimulation is not due to differential TLR9 expression. Therefore, type A(D) CpG-ODNs may contribute to the lupus pathogenesis by inducing MZ-B cell activation, costimulatory molecule expression, and polyclonal Ig secretion. Through increased IL-10 secretion, MZ-B cells may also modify the activity of other cell types, particularly dendritic cells and macrophages.
Cutting Edge: Fas Ligand (CD178) Cytoplasmic Tail Is a Positive Regulator of Fas Ligand-Mediated Cytotoxicity
Authors: Jodo Satoshi , Pidiyar Vyankatesh J. , Xiao Sheng , Furusaki Akira , Sharma Rahul , Koike Takao , Ju Shyr-Te 
Published: April 2014

Abstract
The cytotoxic function of CD178 (Fas ligand (FasL)) is critical to the maintenance of peripheral tolerance and immune-mediated tissue pathology. The active site of FasL resides at the FasL extracellular region (FasLExt) and it functions through binding/cross-linking Fas receptor on target cells. In this study, we report that FasLExt-mediated cytotoxicity is regulated by the FasL cytoplasmic tail (FasLCyt). Deleting the N-terminal 2–70 aa (Δ70) or N-terminal 2–33 aa (Δ33) reduced the cytotoxic strength as much as 30- to 100-fold. By contrast, change in the cytotoxic strength was not observed with FasL deleted of the proline-rich domains (45–74 aa, ΔPRD) in the FasLCyt. Our study identifies a novel function of FasLCyt and demonstrates that FasL2–33, a sequence unique to FasL, is critically required for the optimal expression of FasLExt-mediated cytotoxicity.
Cutting Edge: Itk Is Not Essential for CD28 Signaling in Naive T Cells
Authors: Li Cheng-Rui , Berg Leslie J. 
Published: April 2014

AbstractItk, a member of the Tec family of tyrosine kinases, is critical for TCR signaling, leading to the activation of phospholipase Cγ1. Early biochemical studies performed in tumor cell lines also implicated Itk in CD28 signaling. These data were complemented by functional studies on primary Itk−/− T cells that suggested a negative role for Itk in CD28 signaling. In this report, we describe a thorough analysis of CD28-mediated responses in T cells lacking Itk. Using purified naive CD4+ T cells from Itk−/− mice, we examine a range of responses dependent on CD28 costimulation. We also analyze Akt and glycogen synthase kinase-3β phosphorylation in response to stimulation of CD28 alone. Overall, these experiments demonstrate that CD28 signaling, as well as CD28-mediated costimulation of TCR signaling, function efficiently in the absence of Itk. These findings indicate that Itk is not essential for CD28 signaling in primary naive CD4+ T cells.
Antinuclear Antigen B Cells That Down-Regulate Surface B Cell Receptor during Development to Mature, Follicular Phenotype Do Not Display Features of Anergy In Vitro
Authors: Liu Xiaohe , Manser Tim 
Published: April 2014

AbstractWe previously demonstrated that B cells expressing a transgenic BCR with “dual reactivity” for the hapten arsonate and nuclear autoantigens efficiently complete development to follicular phenotype and stably reside in follicles in vivo. These B cells express very low levels of surface IgM and IgD, suggesting that they avoid central deletion and peripheral anergy by reducing their avidity for autoantigen via surface BCR (sBCR) down-regulation. Since a variety of states of B cell anergy have been previously described, a thorough examination of the functional capabilities of these B cells was required to test this hypothesis. In this study, we show that surface Ig cross-linking induces amounts of proximal BCR signaling in these B cells commensurate with their reduced sBCR levels. Functionally, however, they are comparable to nonautoreactive B cells in cell cycle progression, up-regulation of activation and costimulatory molecules, and Ab-forming cell differentiation when treated with a variety of stimuli in vitro. In addition, these B cells can efficiently process and present Ag and are capable of undergoing cognate interaction with naive TCR-transgenic T cells, resulting in robust IL-2 production. Together, these data reveal a lack of intrinsic anergy involving any known mechanism, supporting the idea that this type of antinuclear Ag B cell becomes indifferent to cognate autoantigen by down-regulating sBCR.
Microtubule Disruption Suppresses Allergic Response through the Inhibition of Calcium Influx in the Mast Cell Degranulation Pathway
Authors: Oka Tatsuya , Hori Masatoshi , Ozaki Hiroshi 
Published: April 2014

AbstractMast cells are secretory cells that release their granules, which contain inflammatory mediators. Some recent data suggested that cytoskeletons play a role in this process. However, the role of microtubules in Ca2+ signaling has not yet been well defined. In this study, we demonstrate that the microtubule cytoskeleton is important to maintain Ca2+ influx in the degranulation pathway of mast cells, using the microtubule depolymerizers nocodazole and colchicine. The microtubule depolymerizers inhibited Ag-induced degranulation in RBL-2H3 cells and bone marrow-derived mast cells. When the cells were stimulated with Ag in the presence of the microtubule depolymerizers, the Ca2+ influx was decreased without affecting Ca2+ release from the endoplasmic reticulum (ER). Capacitative Ca2+ entry, which was induced by inhibitors of Ca2+-ATPase in the ER membrane, thapsigargin and cyclopiazonic acid, was also decreased by nocodazole. Fluorescent probe analysis demonstrated that nocodazole disrupted microtubule formation and changed the cytoplasmic distribution of the ER. The microtubule depolymerizers attenuated the passive cutaneous anaphylaxis reaction in back skin of Sprague Dawley rats. These results suggest that the microtubule cytoskeleton in mast cells is important to maintain Ag-induced capacitative Ca2+ entry, which is responsible for degranulation and the allergic response.