bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electroporation Enables Plasmid Vaccines to Elicit CD8+ T Cell Responses in the Absence of CD4+ T Cells
Authors: Dayball Kelley , Millar James , Miller Mark , Wan Yong Hong , Bramson Jonathan 
Published: April 2014

AbstractIn vivo electroporation dramatically enhances plasmid vaccine efficacy. This enhancement can be attributed to increased plasmid delivery and, possibly, to some undefined adjuvant properties. Previous reports have demonstrated CD8+ T cell priming by plasmid vaccines is strongly dependent upon CD4+ T cell help. Indeed, the efficacy of a plasmid vaccine expressing Escherichia coli β-galactosidase was severely attenuated in MHC class II-deficient (C2D) mice. To determine whether electroporation could compensate for the absence of CD4+ T cell help, C2D mice were immunized by a single administration of plasmid in combination with electroporation using two conditions which differed only by the duration of the pulse (20 or 50 msec). Both conditions elicited robust cellular and humoral responses in wild-type mice, as measured by IFN-γ ELISPOT, anti-β-galactosidase ELISA, and protection from virus challenge. In C2D mice, the cellular response produced by the vaccine combined with the 50-msec pulse, as measured by ELISPOT, was identical to the response in wild-type mice. The 20-msec pulse elicited a milder response that was approximately one-fifth that of the response elicited by the 50-msec pulse. By contrast, the 20-msec conditions provided comparable protection in both wild-type and C2D recipients whereas the protection elicited by the 50-msec conditions in C2D mice was weaker than in wild-type mice. Further investigation is required to understand the discordance between the ELISPOT results and outcome of virus challenge in the C2D mice. Nonetheless, using this technique to prime CD8+ T cells using plasmid vaccines may prove extremely useful when immunizing hosts with limiting CD4+ T cell function, such as AIDS patients.
In Vivo Treatment of Class II MHC-Deficient Mice with Anti-TCR Antibody Restores the Generation of Circulating CD4 T Cells and Optimal Architecture of Thymic Medulla
Authors: Nasreen Mariam , Ueno Tomoo , Saito Fumi , Takahama Yousuke 
Published: April 2014

Abstract
TCR ligation by the self-peptide-associated MHC molecules is essential for T cell development in the thymus, so that class II MHC-deficient mice do not generate CD4+CD8− T cells. The present results show that the administration of anti-TCR mAb into class II MHC-deficient mice restores the generation of CD4+CD8− T cells in vivo. The CD4 T cells were recovered in the thymus, peripheral blood, and the spleen, indicating that the anti-TCR treatment is sufficient for peripheral supply of newly generated CD4 T cells. Unlike peripheral CD4 T cells that disappeared within 5 wk after the treatment, CD4+CD8− thymocytes remained undiminished even after 5 wk, suggesting that CD4 T cells in the thymus are maintained separately from circulating CD4 T cells and even without class II MHC molecules. It was also found that the mass of medullary region in the thymus, which was reduced in class II MHC-deficient mice, was restored by the anti-TCR administration, suggesting that the medulla for CD4+CD8− thymocytes is formed independently of the medulla for CD4−CD8+ thymocytes. These results indicate that in vivo anti-TCR treatment in class II MHC-deficient mice restores the generation of circulating CD4 T cells and optimal formation of the medulla in the thymus, suggesting that anti-TCR Ab may be useful for clinical treatment of class II MHC deficiencies.
Death Decoy Receptor TR6/DcR3 Inhibits T Cell Chemotaxis In Vitro and In Vivo
Authors: Shi Guixiu , Wu Yulian , Zhang Jun , Wu Jiangping 
Published: April 2014

AbstractTR6/DcR3 is a secreted molecule belonging to the TNFR family. Its ligands are LIGHT, Fas ligand, and TL1A, all TNF family members. TR6 is expressed in some tumors and is hypothesized to endow tumor cells with survival advantages by blocking Fas-mediated apoptosis. It can also inhibit T cell activation by interfering with two-way T cell costimulation between LIGHT and HveA. In this study, we discovered a novel function of TR6: inhibition of T cell chemotaxis. Human T cells pretreated with soluble or solid-phase TR6-Fc showed compromised migration toward CXCL12/stromal cell-derived factor 1α in vitro in a Transwell assay. Such an effect could also be observed in T cells pretreated with soluble or solid-phase HveA-Fc or anti-LIGHT mAb, suggesting that LIGHT reverse signaling was likely responsible for chemotaxis inhibition. TR6 pretreatment also led to T cell chemotaxis suppression in vivo in the mice, confirming in vivo relevance of the in vitro observation. Mechanistically, a small GTPase Cdc42 failed to be activated after TR6 pretreatment of human T cells, and further downstream, p38 mitogen-activated protein kinase activation, actin polymerization, and pseudopodium formation were all down-regulated in the treated T cells. This study revealed a previously unknown function of TR6 in immune regulation, and such an effect could conceivably be explored for therapeutic use in controlling undesirable immune responses.
Human Tumor-Derived Heat Shock Protein 96 Mediates In Vitro Activation and In Vivo Expansion of Melanoma- and Colon Carcinoma-Specific T Cells
Authors: Rivoltini Licia , Castelli Chiara , Carrabba Matteo , Mazzaferro Vincenzo , Pilla Lorenzo , Huber Veronica , Coppa Jorgelina , Gallino Gianfrancesco , Scheibenbogen Carmen , Squarcina Paola , Cova Agata , Camerini Roberto , Lewis Jonathan J. , Srivastava Pramod K. , Parmiani Giorgio 
Published: April 2014

Abstract
Heat shock proteins (hsp) 96 play an essential role in protein metabolism and exert stimulatory activities on innate and adaptive immunity. Vaccination with tumor-derived hsp96 induces CD8+ T cell-mediated tumor regressions in different animal models. In this study, we show that hsp96 purified from human melanoma or colon carcinoma activate tumor- and Ag-specific T cells in vitro and expand them in vivo. HLA-A*0201-restricted CD8+ T cells recognizing Ags expressed in human melanoma (melanoma Ag recognized by T cell-1 (MART-1)/melanoma Ag A (Melan-A)) or colon carcinoma (carcinoembryonic Ag (CEA)/epithelial cell adhesion molecule (EpCAM)) were triggered to release IFN-γ and to mediate cytotoxic activity by HLA-A*0201-matched APCs pulsed with hsp96 purified from tumor cells expressing the relevant Ag. Such activation occurred in class I HLA-restricted fashion and appeared to be significantly higher than that achieved by direct peptide loading. Immunization with autologous tumor-derived hsp96 induced a significant increase in the recognition of MART-1/Melan-A27–35 in three of five HLA-A*0201 melanoma patients, and of CEA571–579 and EpCAM263–271 in two of five HLA-A*0201 colon carcinoma patients, respectively, as detected by ELISPOT and HLA/tetramer staining. These increments in Ag-specific T cell responses were associated with a favorable disease course after hsp96 vaccination. Altogether, these data provide evidence that hsp96 derived from human tumors can present antigenic peptides to CD8+ T cells and activate them both in vitro and in vivo, thus representing an important tool for vaccination in cancer patients.
Genetic Reprogramming of Primary Human T Cells Reveals Functional Plasticity in Th Cell Differentiation
Authors: Sundrud Mark S. , Grill Stacy M. , Ni Donghui , Nagata Kinya , Alkan Sefik S. , Subramaniam Arun , Unutmaz Derya 
Published: April 2014

Abstract
Activation of naive T cells through the TCR and cytokine signals directs their differentiation into effector or memory subsets with different cytokine profiles. Here, we tested the flexibility of human Th1 or Th2 differentiation by forced expression of transcription factors T-bet and GATA-3. Ectopic expression of T-bet and GATA-3 in freshly isolated human TN cells resulted in their differentiation to a Th1 and Th2 phenotype, respectively, in the absence of polarizing cytokines. Introduction of GATA-3 into lineage-committed Th1 cells induced the expression of Th2-specific cytokines (IL-4 and IL-5) and chemotactic receptors (CCR4, chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2). However, these cells partially maintained their Th1-specific profile (IFN-γ and IL-12Rβ2 expression). Conversely, expression of T-bet in lineage-committed Th2 cells caused a more profound switch to the Th1 phenotype, including the up-regulation of CXCR3 and down-regulation of CCR4 and CRTH2. Interestingly, similar to the naive T cell subset, central memory T cells were also largely programmed toward Th1 or Th2 effector cells upon expression of T-bet and GATA-3, respectively. However, expression of these transcription factors in effector memory T cells was much less influential on cytokine and chemokine receptor expression profiles. Our results reveal remarkable plasticity in the differentiation programs of human memory T cells. This flexibility is progressively diminished as cells mature from naive to effector T cells. These findings have important implications in understanding the molecular mechanisms of human T cell differentiation and for devising novel therapeutic strategies aimed at immunomodulation of skewed effector T cell responses.
Induction of Macrophage Insulin-Like Growth Factor-I Expression by the Th2 Cytokines IL-4 and IL-13
Authors: Wynes Murry W. , Riches David W. H. 
Published: April 2014

Abstract
Macrophage-derived insulin-like growth factor-I (IGF-I) has long been implicated in the pathogenesis of the interstitial lung disease, idiopathic pulmonary fibrosis, in part, by its ability to 1) stimulate the proliferation and survival of fibroblasts and myofibroblasts and 2) promote collagen matrix synthesis by these cells. However, little is known about the mechanisms that stimulate the expression of IGF-I by macrophages. Previous studies have shown that the development of pulmonary fibrosis is accompanied by enhanced expression of Th2-profile cytokines, especially IL-4, and diminished expression of Th1 cytokines, including IFN-γ. In addition, in vitro studies have shown that IFN-γ down-regulates the expression of IGF-I. Thus, the paucity of IFN-γ in the fibrotic lung may favor increased growth factor production by allowing Th2 cytokines to predominate. In view of these findings, we investigated the hypothesis that Th2 cytokines stimulate the expression of IGF-I by macrophages. Incubation with IL-4 or IL-13 led to concentration- and time-dependent increases in the expression of IGF-I mRNA and the secretion of IGF-I protein by mouse macrophages as a consequence of increased transcription of IGF-I pre-mRNA. Exposure of macrophages to IL-4 in the presence of IFN-γ inhibited the increase in the expression of IGF-I. Studies using STAT6-deficient macrophages indicated that the increase in IGF-I expression was dependent on STAT6. In addition, the down-regulation of IGF-I expression by IFN-γ was absent in STAT1-deficient macrophages. Collectively, these findings define a homeostatic mechanism in which Th2 cytokines promote, and Th1 cytokines inhibit, the expression of IGF-I by macrophages.
CC Chemokine Ligand 2 and Its Receptor Regulate Mucosal Production of IL-12 and TGF-β in High Dose Oral Tolerance
Authors: DePaolo R. William , Rollins Barrett J. , Kuziel William , Karpus William J. 
Published: April 2014

AbstractOral tolerance is the result of a complex immunoregulatory strategy used by the gut and its associated lymphoid tissues to render the peripheral immune system unresponsive to nonpathogenic proteins, such as food or commensal bacteria. The mechanism of oral tolerance induction and maintenance is not well understood. We have previously shown that the chemokine, CC chemokine ligand 2 (CCL2), is important for the induction and maintenance of oral tolerance. To address the role CCL2 plays in oral tolerance, we used both CCL2−/− and CCR2−/− mice. Cells from the spleen, mesenteric lymph nodes, and peripheral lymph nodes of CCL2−/− and CCR2−/− mice fed high doses of OVA showed robust proliferative responses compared with cells from Ag-fed wild-type mice. CCL2−/− and CCR2−/− mice also produced high amounts of Th1 cytokines such as IL-2 and IFN-γ and very low amounts of IL-4 and IL-10. The ability of APCs from the gut of CCL2−/− and CCR2−/− OVA-fed mice to stimulate an indicator T cell line was evaluated. APCs from the Peyer’s patch of OVA-fed knockout animals could induce a T cell response measured by an increase in proliferation and generation of IL-12 and IFN-γ with a concomitant reduction of TGF-β compared with wild-type controls that did not induce a Th1 response. These data indicate that CCL2 and signaling through its receptor CCR2 is critical for the induction of oral tolerance by regulating Ag presentation leading to a disruption in the balance of inflammatory and regulatory cytokines.
Cellular Events Involved in Butyric Acid-Induced T Cell Apoptosis
Authors: Kurita-Ochiai Tomoko , Amano Shigeru , Fukushima Kazuo , Ochiai Kuniyasu 
Published: April 2014

Abstract
We have previously demonstrated that butyric acid induces cytotoxicity and apoptosis of murine thymocytes, splenic T cells, and human Jurkat T cells. Therefore, to determine the apoptotic signaling pathway induced by butyric acid, we investigated the contribution of reactive oxygen species (ROS), mitochondria, ceramide, and mitogen-activated protein kinases in butyric acid-induced human Jurkat cell apoptosis. After exposure of cells to butyric acid, a pronounced accumulation of ROS was seen. Pretreatment of cells with the antioxidant N-acetyl-cysteine or 3-aminobenzamide attenuated butyric acid-induced apoptosis through a reduction of ROS generation. Cytochrome c, apoptosis-inducing factor, and second mitochondria-derived activator of caspases protein release from mitochondria into the cytosol were detected shortly after butyric acid treatment. Exposure of cells to butyric acid resulted in an increase in cellular ceramide in a time-dependent fashion. In addition, butyric acid-induced apoptosis was inhibited by DL-threo-dihidrosphingosine, a potent inhibitor of sphingosine kinase. Using anti-extracellular signal-regulated kinase (ERK), anti-c-Jun N-terminal kinase (JNK), and anti-p38 phosphospecific Abs, we showed a decrease in ERK, but not in JNK and p38 phosphorylation after treatment of cells with butyric acid. Pretreatment of cells with the JNK inhibitor SP600125 attenuated the effect of butyric acid on apoptosis, whereas no effect was seen with the p38 inhibitor SB202190 or the ERK inhibitor PD98059. Taken together, our results indicate that butyric acid-induced T cell apoptosis is mediated by ceramide production, ROS synthesis in mitochondria, and JNK activation in the mitogen-activated protein kinase cascade. Finally, these results were further substantiated by the expression profile of butyric acid-treated Jurkat cells obtained by means of cDNA array.
Exogenous Administration of Gangliosides Inhibits FcεRI-Mediated Mast Cell Degranulation by Decreasing the Activity of Phospholipase Cγ
Authors: Dráberová Lubica , Dudková Lenka , Boubelík Michael , Tolarová Helena , Šmíd František , Dráber Petr 
Published: April 2014

AbstractGangliosides released from tumor cells, as well as administered exogenously, suppress the immune responses by largely unknown mechanisms. We show here that a pretreatment of rat basophilic leukemia cells with isolated brain gangliosides inhibited the release of preformed secretory mediators from cells activated via FcεRI but not Thy-1 glycoprotein. Exogenously administered gangliosides also affected the cell-substrate adhesion and the levels of polymeric filamentous actin in Ag-activated cells. Although the production of phosphoinositides was also decreased, enzymatic activity of phosphatidylinositol 3-kinase was not inhibited. Gangliosides had no or only marginal effect on the association of aggregated FcεRI with glycosphingolipid-enriched membranes and on tyrosine phosphorylation of FcεRI and the linker for activation of T cells. Though pretreatment with gangliosides did not inhibit the association of linker for activation of T cells with phospholipase C (PLC)γ1 and PLCγ2, tyrosine phosphorylation of these enzymes, as well as their enzymatic activities and association with detergent-insoluble signaling assemblies were reduced. This resulted in a decreased production of inositol 1,4,5-trisphosphate and an inhibition of Ca2+ mobilization. The combined data support the concept that exogenously administered gangliosides interfere with those properties of glycosphingolipid-enriched membranes that are important for the formation of plasma membrane-associated signaling assemblies containing PLCγ but not for initial tyrosine phosphorylation of FcεRI subunits.
Substance P Regulates Th1-Type Colitis in IL-10 Knockout Mice
Authors: Weinstock Joel V. , Blum Arthur , Metwali Ahmed , Elliott David , Bunnett Nigel , Arsenescu Razvan 
Published: April 2014

Abstract
Substance P (SP) is a proinflammatory molecule that interacts with a neurokinin 1 receptor (NK-1R), which is on T cells and helps control IFN-γ production. IL-10−/− mice given a nonsteroidal anti-inflammatory drug (NSAID) develop Th1 colitis. We studied the importance of SP and NK-1R in this colitis model. LP T cells were isolated to study their NK-1R expression. LP T cells from IL-10−/− mice expressed NK-1R and produced IFN-γ only after NSAID treatment and induction of colitis. LP T cells from NSAID-treated wild-type controls or from age-matched untreated IL-10−/− animals did not express NK-1R or produce IFN-γ. Experiments showed that IL-12 induced NK-1R transcription in CD4+ T cells cultured in vitro. However, T cells cultured with IL-12 and IL-10 did not express NK-1R. IL-10 also down-modulated ongoing NK-1R expression. Mice given NK-1R antagonist after NSAID induction of severe colitis showed nearly complete reversal of inflammation, and LP T cells ceased IFN-γ secretion. Thus, intestinal inflammation in IL-10−/− mice is associated with the appearance of NK-1R in mucosal T cells, and an interplay between IL-12 and IL-10 regulates T cell NK-1R transcription. NK-1R antagonist reverses ongoing intestinal inflammation attesting to the importance of SP and its receptor in mucosal inflammation.
SεSμ and SεSγ Switch Circles in Human Nasal Mucosa Following Ex Vivo Allergen Challenge: Evidence for Direct as Well as Sequential Class Switch Recombination
Authors: Cameron Lisa , Gounni Abdelilah Soussi , Frenkiel Saul , Lavigne François , Vercelli Donata , Hamid Qutayba 
Published: April 2014

AbstractB cells switch to IgE under the influence of IL-4, IL-13, and CD40 costimulation through a multistep process involving ε germline transcription and class switch recombination. Classically, switching has been considered an event restricted to lymphoid tissues; however, ε germline transcripts (I(initiator)ε RNA) have been observed within lung, sinus, and nasal tissue of individuals with asthma, sinusitis, and rhinitis. Furthermore, nasal mucosal tissue from allergic rhinitics produces ε germline transcripts following ex vivo allergen challenge. Collectively, these studies raised the possibility that switching to IgE may occur locally, at sites of allergic inflammation. Although ε germline transcripts are considered necessary to target the IgE locus, it is class switch recombination that ultimately leads to de novo IgE production. In this study, we demonstrate that SεSμ DNA switch circles (products of class switch recombination) as well as Iε and Cε RNA are produced within nasal tissue from allergic individuals following ex vivo allergen challenge. ε germline transcription was inhibited when tissue was cultured with a combination of allergen and neutralizing Abs against IL-4 and IL-13, indicating that de novo cytokine production mediated the isotype switch. We also show allergen-induced appearance of SεSγ DNA switch circles and up-regulation of Cγ4 mRNA, illustrating that sequential switching to IgE also occurred. This work strongly suggests that B cells residing within the nasal mucosa undergo switching to IgE in the context of a local immune response to allergen.
Genetic Evidence for Involvement of Classical Complement Pathway in Induction of Experimental Autoimmune Myasthenia Gravis
Authors: Tüzün Erdem , Scott Benjamin G. , Goluszko Elzbieta , Higgs Stephen , Christadoss Premkumar 
Published: April 2014

AbstractAbs to acetylcholine receptor (AChR) and complement are the major constituents of pathogenic events causing neuromuscular junction destruction in both myasthenia gravis (MG) and experimental autoimmune MG (EAMG). To analyze the differential roles of the classical vs alternative complement pathways in EAMG induction, we immunized C3−/−, C4−/−, C3+/−, and C4+/− mice and their control littermates (C3+/+ and C4+/+ mice) with AChR in CFA. C3−/− and C4−/− mice were resistant to disease, whereas mice heterozygous for C3 or C4 displayed intermediate susceptibility. Although C3−/− and C4−/− mice had anti-AChR Abs in their sera, anti-AChR IgG production by C3−/− mice was significantly suppressed. Both C3−/− and C4−/− mice had reduced levels of B cells and increased expression of apoptotis inducers (Fas ligand, CD69) and apoptotic cells in lymph nodes. Immunofluorescence studies showed that the neuromuscular junction of C3−/− and C4−/− mice lacked C3 or membrane attack complex deposits, despite having IgG deposits, thus providing in vivo evidence for the incapacity of anti-AChR IgGs to induce full-blown EAMG without the aid of complements. The data provide the first direct genetic evidence for the classical complement pathway in the induction of EAMG induced by AChR immunization. Accordingly, severe MG and other Ab- and complement-mediated diseases could be effectively treated by inhibiting C4, thus leaving the alternative complement pathway intact.
Curcumin (Diferuloylmethane) Inhibits Constitutive and IL-6-Inducible STAT3 Phosphorylation in Human Multiple Myeloma Cells
Authors: Bharti Alok C. , Donato Nicholas , Aggarwal Bharat B. 
Published: April 2014

Abstract
Numerous reports suggest that IL-6 promotes survival and proliferation of multiple myeloma (MM) cells through the phosphorylation of a cell signaling protein, STAT3. Thus, agents that suppress STAT3 phosphorylation have potential for the treatment of MM. In the present report, we demonstrate that curcumin (diferuloylmethane), a pharmacologically safe agent in humans, inhibited IL-6–induced STAT3 phosphorylation and consequent STAT3 nuclear translocation. Curcumin had no effect on STAT5 phosphorylation, but inhibited the IFN-α-induced STAT1 phosphorylation. The constitutive phosphorylation of STAT3 found in certain MM cells was also abrogated by treatment with curcumin. Curcumin-induced inhibition of STAT3 phosphorylation was reversible. Compared with AG490, a well-characterized Janus kinase 2 inhibitor, curcumin was a more rapid (30 min vs 8 h) and more potent (10 μM vs 100 μM) inhibitor of STAT3 phosphorylation. In a similar manner, the dose of curcumin completely suppressed proliferation of MM cells; the same dose of AG490 had no effect. In contrast, a cell-permeable STAT3 inhibitor peptide that can inhibit the STAT3 phosphorylation mediated by Src blocked the constitutive phosphorylation of STAT3 and also suppressed the growth of myeloma cells. TNF-α and lymphotoxin also induced the proliferation of MM cells, but through a mechanism independent of STAT3 phosphorylation. In addition, dexamethasone-resistant MM cells were found to be sensitive to curcumin. Overall, our results demonstrated that curcumin was a potent inhibitor of STAT3 phosphorylation, and this plays a role in the suppression of MM proliferation.