bluuebunny/crossref_metadata_2025_split huggingface dataset:
Commensal Bacteria Exacerbate Intestinal Inflammation but Are Not Essential for the Development of Murine Ileitis
Authors: Bamias Giorgos , Okazawa Akira , Rivera-Nieves Jesus , Arseneau Kristen O. , De La Rue Sarah A. , Pizarro Theresa T. , Cominelli Fabio 
Published: April 2014

Abstract
The pathogenesis of Crohn’s disease has been associated with a dysregulated response of the mucosal immune system against intraluminal Ags of bacterial origin. In this study, we have investigated the effects of germfree (GF) conditions in the SAMP1/YitFc murine model of Crohn’s disease-like ileitis. We show that the bacterial flora is not essential for ileitis induction, because GF SAMP1/YitFc mice develop chronic ileitis. However, compared with disease in specific pathogen-free (SPF) mice, ileitis in GF mice is significantly attenuated, and is associated with delayed lymphocytic infiltration and defective mucosal expression of Th2 cytokines. In addition, we demonstrate that stimulation with purified fecal Ags from SPF, but not GF mice leads to the generation of IL-4-secreting effector lymphocytes. This result suggests that commensal bacteria drive Th2 responses characteristic of the chronic phase of SAMP1/YitFc ileitis. Finally, adoptive transfer of CD4-positive cells from GF, but not SPF mice induces severe colitis in SCID recipients. These effects were associated with a decreased frequency of CD4+CD25+Foxp3+ T cells in the mesenteric lymph nodes of GF mice compared with SPF mice, as well as lower relative gene expression of Foxp3 in CD4+CD25+ T cells in GF mice. It is therefore apparent that, in the absence of live intraluminal bacteria, the regulatory component of the mucosal immune system is compromised. All together, our results indicate that in SAMP1/YitFc mice, bacterial flora exacerbates intestinal inflammation, but is not essential for the generation of the chronic ileitis that is characteristic of these mice.
Unique Human Tumor Antigens: Immunobiology and Use in Clinical Trials
Authors: Parmiani Giorgio , De Filippo Annamaria , Novellino Luisa , Castelli Chiara 
Published: April 2014

Abstract
The individual, unique tumor Ags, which characterize each single tumor, were described 50 years ago in rodents but their molecular characterization was limited to few of them and obtained during the last 20 years. Here we summarize the evidence for the existence and the biological role of such Ags in human tumors, although such evidence was provided only during the last 10 years and by a limited number of studies, a fact leading to a misrepresentation of unique Ags in human tumor immunology. This was also due to the increasing knowledge on the shared, self-human tumor Ags, which have been extensively used as cancer vaccines. In this review, we highlight the biological and clinical importance of unique Ags and suggest how they could be used in clinical studies aimed at assessing their immunogenic and clinical potential both in active and adoptive immunotherapy of human tumors.
Cutting Edge: The PI3K p110δ Is Required for Down-Regulation of RAG Expression in Immature B Cells
Authors: Llorian Miriam , Stamataki Zania , Hill Susan , Turner Martin , Mårtensson Inga-Lill 
Published: April 2014

Abstract
At the immature B cell stage the BCR signals the down-regulation of the RAG genes and Ig L chain (LC) allelic and isotype exclusion. The signaling pathway that regulates these events is poorly characterized. We demonstrate that immature B cells from mice deficient in the PI3K catalytic subunit p110δ fail to suppress RAG expression and inappropriately recombine κ and λ LC loci. In addition, in the presence of the autoantigen, clonal deletion and receptor editing still takes place, demonstrating that these processes are independent of p110δ. These results demonstrate a role for p110δ in the regulation of RAG gene expression and thereby LC allelic/isotype exclusion.
Distinct Differentiation Potential of Blood Monocyte Subsets in the Lung
Authors: Landsman Limor , Varol Chen , Jung Steffen 
Published: April 2014

Abstract
Peripheral blood monocytes are a population of circulating mononuclear phagocytes that harbor potential to differentiate into macrophages and dendritic cells. As in humans, monocytes in the mouse comprise two phenotypically distinct subsets that are Gr1highCX3CR1int and Gr1lowCX3CR1high, respectively. The question remains whether these populations contribute differentially to the generation of peripheral mononuclear phagocytes. In this study, we track the fate of adoptively transferred, fractionated monocyte subsets in the lung of recipient mice. We show that under inflammatory and noninflammatory conditions, both monocyte subsets give rise to pulmonary dendritic cells. In contrast, under the conditions studied, only Gr1lowCX3CR1high monocytes, but not Gr1highCX3CR1int cells, had the potential to differentiate into lung macrophages. However, Gr1highCX3CR1int monocytes could acquire this potential upon conversion into Gr1lowCX3CR1high cells. Our results therefore indicate an intrinsic dichotomy in the differentiation potential of the two main blood monocyte subsets.
Stromal Derived Growth Factor-1α: Another Mediator in Neural-Emerging Immune System through Tac1 Expression in Bone Marrow Stromal Cells
Authors: Corcoran Kelly E. , Patel Nitixa , Rameshwar Pranela 
Published: April 2014

Abstract
Stromal cell-derived growth factor-1α (SDF-1α) is a member of the CXC chemokines and interacts with the G protein, seven-transmembrane CXCR4 receptor. SDF-1α acts as a chemoattractant for immune and hemopoietic cells. The Tac1 gene encodes peptides belonging to the tachykinin family with substance P being the predominant member. Both SDF-1α and Tac1 peptides are relevant hemopoietic regulators. This study investigated the effects of SDF-1α on Tac1 expression in the major hemopoietic supporting cells, the bone marrow stroma, and addresses the consequence to hemopoiesis. Reporter gene assays with the 5′ flanking region of Tac1 showed a bell-shaped effect of SDF-1α on luciferase activity with 20 ng/ml SDF-1α acting as stimulator, whereas 50 and 100 ng/ml SDF-1α acted as inhibitors. Gel shift assays and transfection with wild-type and mutant IκB indicate NF-κB as a mediator in the repressive effects at 50 and 100 ng/ml SDF-1α. Northern analyses and ELISA showed correlations among reporter gene activities, mRNA (β-preprotachykinin I), and protein levels for substance P. Of relevance is the novel finding by long-term culture-initiating cell assays that showed an indirect effect of SDF-1α on hemopoiesis through substance P production. The results also showed neurokinin 1 and not neurokinin 2 as the relevant receptor. Another crucial finding is that substance P does not regulate the production of SDF-1α in stroma. The studies indicate that SDF-1α levels above baseline production in bone marrow stroma induce the production of substance P to stimulate hemopoiesis. Substance P, however, does not act as autocrine stimulator to induce the production of SDF-1α. This study adds SDF-1α as a mediator within the neural-immune-hemopoietic axis.
Regulation of CD8+ T Lymphocyte Effector Function and Macrophage Inflammatory Cytokine Production by Retinoic Acid Receptor γ
Authors: Dzhagalov Ivan , Chambon Pierre , He You-Wen 
Published: April 2014

Abstract
Vitamin A and its derivatives regulate a broad array of immune functions. The effects of these retinoids are mediated through members of retinoic acid receptors (RARs) and retinoid X receptors. However, the role of individual retinoid receptors in the pleiotropic effects of retinoids remains unclear. To dissect the role of these receptors in the immune system, we analyzed immune cell development and function in mice conditionally lacking RARγ, the third member of the RAR family. We show that RARγ is dispensable for T and B lymphocyte development, the humoral immune response to a T-dependent Ag and in vitro Th cell differentiation. However, RARγ-deficient mice had a defective primary and memory CD8+ T cell response to Listeria monocytogenes infection. Unexpectedly, RARγ-deficient macrophages exhibited impaired inflammatory cytokine production upon TLR stimulation. These results suggest that under physiological condition, RARγ is a positive regulator of inflammatory cytokine production.
Bacterial c-di-GMP Is an Immunostimulatory Molecule
Authors: Karaolis David K. R. , Means Terry K. , Yang De , Takahashi Munehisa , Yoshimura Teizo , Muraille Eric , Philpott Dana , Schroeder John T. , Hyodo Mamoru , Hayakawa Yoshihiro , Talbot Brian G. , Brouillette Eric , Malouin François 
Published: April 2014

Abstract
Cyclic diguanylate (c-di-GMP) is a bacterial intracellular signaling molecule. We have shown that treatment with exogenous c-di-GMP inhibits Staphylococcus aureus infection in a mouse model. We now report that c-di-GMP is an immodulator and immunostimulatory molecule. Intramammary treatment of mice with c-di-GMP 12 and 6 h before S. aureus challenge gave a protective effect and a 10,000-fold reduction in CFUs in tissues (p &lt; 0.001). Intramuscular vaccination of mice with c-di-GMP coinjected with S. aureus clumping factor A (ClfA) Ag produced serum with significantly higher anti-ClfA IgG Ab titers (p &lt; 0.001) compared with ClfA alone. Intraperitoneal injection of mice with c-di-GMP activated monocyte and granulocyte recruitment. Human immature dendritic cells (DCs) cultured in the presence of c-di-GMP showed increased expression of costimulatory molecules CD80/CD86 and maturation marker CD83, increased MHC class II and cytokines and chemokines such as IL-12, IFN-γ, IL-8, MCP-1, IFN-γ-inducible protein 10, and RANTES, and altered expression of chemokine receptors including CCR1, CCR7, and CXCR4. c-di-GMP-matured DCs demonstrated enhanced T cell stimulatory activity. c-di-GMP activated p38 MAPK in human DCs and ERK phosphorylation in human macrophages. c-di-GMP is stable in human serum. We propose that cyclic dinucleotides like c-di-GMP can be used clinically in humans and animals as an immunomodulator, immune enhancer, immunotherapeutic, immunoprophylactic, or vaccine adjuvant.
Peripheral Tolerance Induction Using Ethylenecarbodiimide-Fixed APCs Uses both Direct and Indirect Mechanisms of Antigen Presentation for Prevention of Experimental Autoimmune Encephalomyelitis
Authors: Turley Danielle M. , Miller Stephen D. 
Published: April 2014

Abstract
MHC class II (MHC II)-restricted T cell responses are a common driving force of autoimmune disease. Accordingly, numerous therapeutic strategies target CD4+ T cells with the hope of attenuating autoimmune responses and restoring self-tolerance. We have previously reported that i.v. treatment with Ag-pulsed, ethylenecarbodiimide (ECDI)-fixed splenocytes (Ag-SPs) is an efficient protocol to induce Ag-specific tolerance for prevention and treatment of experimental autoimmune encephalomyelitis (EAE). Ag-SPs coupled with peptide can directly present peptide:MHC II complexes to target CD4+ T cells in the absence of costimulation to induce anergy. However, Ag-SPs coupled with whole protein also efficiently attenuates Ag-specific T cell responses suggesting the potential contribution of alternative indirect mechanisms/interactions between the Ag-SPs and target CD4+ T cells. Thus, we investigated whether MHC II compatibility was essential to the underlying mechanisms by which Ag-SP induces tolerance during autoimmune disease. Using MHC-deficient, allogeneic, and/or syngeneic donor Ag-SPs, we show that MHC compatibility between the Ag-SP donor and the host is not required for tolerance induction. Interestingly, we found that ECDI treatment induces apoptosis of the donor cell population which promotes uptake and reprocessing of donor cell peptides by host APCs resulting in the apparent MHC II-independent induction of tolerance. However, syngeneic donor cells are more efficient at inducing tolerance, suggesting that Ag-SPs induce functional Ag-SP tolerance via both direct and indirect (cross-tolerance) mechanisms leading to prevention and effective treatment of autoimmune disease.
The N Terminus of the Non-T Cell Activation Linker (NTAL) Confers Inhibitory Effects on Pre-B Cell Differentiation
Authors: Herzog Sebastian , Jumaa Hassan 
Published: April 2014

Abstract
SLP-65 and the linker for activation of T cells (LAT) are central adaptor proteins that link the activated pre-BCR to downstream events in pre-B cells. Recently, a new transmembrane adaptor called NTAL/LAB/LAT2 (hereafter called NTAL for non-T cell activation linker) with striking functional and structural similarity to LAT has been identified in B cells. In this study, we compare the function of NTAL and LAT in pre-BCR signaling and show that, in contrast to LAT, NTAL does not induce pre-BCR down-regulation, calcium flux, or pre-B cell differentiation. To test whether differences between NTAL-mediated and LAT-mediated signaling are caused by the missing phospholipase C (PLC)-γ binding motif in NTAL, we inserted the PLC-γ1/2 binding motif of LAT into NTAL. This insertion rendered NTAL capable of activating pre-BCR down-regulation and calcium flux. Unexpectedly however, the ability of NTAL to induce calcium flux was not sufficient to promote pre-B cell differentiation, suggesting that the PLC-γ binding motif has only partial effects on NTAL-mediated pre-BCR signaling. By generating chimeric swap mutants, we identified the N terminus of NTAL as an inhibitory domain that prevents pre-B cell differentiation while allowing pre-BCR down-regulation and receptor-mediated calcium flux. Our data suggest that, in addition to the missing PLC-γ1/2 binding motif, the N terminus is responsible for the functional differences between NTAL and LAT in pre-B cells.
Mucosal HIV-1 Pox Virus Prime-Boost Immunization Induces High-Avidity CD8+ T Cells with Regime-Dependent Cytokine/Granzyme B Profiles
Authors: Ranasinghe Charani , Turner Stephen J. , McArthur Craig , Sutherland Duncan B. , Kim Jee-Hye , Doherty Peter C. , Ramshaw Ian A. 
Published: April 2014

Abstract
The quality of virus-specific CD8+ CTL immune responses generated by mucosal and systemic poxvirus prime-boost vaccines were evaluated in terms of T cell avidity and single-cell analysis of effector gene expression. Intranasal (I.N.) immunization regimes generated higher avidity CTL responses specific for HIV KdGag197–205 (amino acid sequence AMQMLKETI; H-2Kd binding) compared with i.m. immunization regime. Single-cell RT-PCR of KdGag197–205-specific mucosal and systemic CTL revealed that the cytokine and granzyme B expression profiles were dependent on both the route and time after immunization. The I.N./i.m.-immunized group elicited elevated number of CTL-expressing granzyme B mRNA from the genitomucosal sites compared with the i.m./i.m. regime. Interestingly, CTL generated after both I.N. or i.m. immunization demonstrated expression of Th2 cytokine IL-4 mRNA that was constitutively expressed over time, although lower numbers were observed after I.N./I.N. immunization. Results suggest that after immunization, Ag-specific CTL expression of IL-4 may be an inherent property of the highly evolved poxvirus vectors. Current observations indicate that the quality of CTL immunity generated after immunization can be influenced by the inherent property of vaccine vectors and route of vaccine delivery. A greater understanding of these factors will be crucial for the development of effective vaccines in the future.
Rapid Clonal Expansion and Prolonged Maintenance of Memory CD8+ T Cells of the Effector (CD44highCD62Llow) and Central (CD44highCD62Lhigh) Phenotype by an Archaeosome Adjuvant Independent of TLR2
Authors: Krishnan Lakshmi , Gurnani Komal , Dicaire Chantal J. , van Faassen Henk , Zafer Ahmed , Kirschning Carsten J. , Sad Subash , Sprott G. Dennis 
Published: April 2014

Abstract
Vaccines capable of eliciting long-term T cell immunity are required for combating many diseases. Live vectors can be unsafe whereas subunit vaccines often lack potency. We previously reported induction of CD8+ T cells to Ag entrapped in archaeal glycerolipid vesicles (archaeosomes). In this study, we evaluated the priming, phenotype, and functionality of the CD8+ T cells induced after immunization of mice with OVA-Methanobrevibacter smithii archaeosomes (MS-OVA). A single injection of MS-OVA evoked a profound primary response but the numbers of H-2KbOVA257–264-specific CD8+ T cells declined by 14–21 days, and &lt;1% of primarily central phenotype (CD44highCD62Lhigh) cells persisted. A booster injection of MS-OVA at 3–11 wk promoted massive clonal expansion and a peak effector response of ∼20% splenic/blood OVA257–264-specific CD8+ T cells. Furthermore, contraction was protracted and the memory pool (IL-7Rαhigh) of ∼5% included effector (CD44highCD62Llow) and central (CD44highCD62Lhigh) phenotype cells. Recall response was observed even at &gt;300 days. CFSE-labeled naive OT-1 (OVA257–264 TCR transgenic) cells transferred into MS-OVA-immunized recipients cycled profoundly (&gt;90%) within the first week of immunization indicating potent Ag presentation. Moreover, ∼25% cycling of Ag-specific cells was seen for &gt;50 days, suggesting an Ag depot. In vivo, CD8+ T cells evoked by MS-OVA killed &gt;80% of specific targets, even at day 180. MS-OVA induced responses similar in magnitude to Listeria monocytogenes-OVA, a potent live vector. Furthermore, protective CD8+ T cells were induced in TLR2-deficient mice, suggesting nonengagement of TLR2 by archaeal lipids. Thus, an archaeosome adjuvant vaccine represents an alternative to live vectors for inducing CD8+ T cell memory.
Signaling in Lipopolysaccharide-Induced Stabilization of Formyl Peptide Receptor 1 mRNA in Mouse Peritoneal Macrophages
Authors: Mandal Palash , Hamilton Thomas 
Published: April 2014

Abstract
To identify the TLR4-initiated signaling events that couple to formyl peptide receptor (FPR)1 mRNA stabilization, macrophages were treated with LPS along with a selection of compounds targeting several known signaling pathways. Although inhibitors of protein tyrosine kinases, MAPKs, and stress-activated kinases had little or no effect on the response to LPS, LY294002 (LY2) and parthenolide (an IκB kinase inhibitor) were both potent inhibitors. LY2 but not parthenolide blocked the LPS-induced stabilization of FPR1 mRNA. Although both LY2 and wortmannin effectively blocked PI3K activity, wortmannin had little effect on FPR1 expression and did not modulate the decay of FPR1 mRNA. Moreover, although LY2 was demonstrated to be a potent inhibitor of PI3K activity, a structural analog of LY2, LY303511 (LY3), which did not inhibit PI3K, was equally effective at preventing LPS-stimulated FPR1 expression. The mammalian target of rapamycin activity (measured as phospho-p70S6 kinase) was activated by LPS but not significantly blocked by LY2. In addition, although rapamycin blocked mTOR activity, it did not inhibit FPR1 mRNA expression. Finally, the mechanisms involved in stabilization of FPR1 by LPS could be distinguished from those involved in stabilization of AU-rich mRNAs because the prolonged half-life of FPR1 mRNA was insensitive to the inhibition of p38 MAPK. These findings demonstrate that LY2/LY3 targets a novel TLR4-linked signaling pathway that selectively couples to the stabilization of FPR1 mRNA.
A SmD Peptide Induces Better Antibody Responses to Other Proteins within the Small Nuclear Ribonucleoprotein Complex than to SmD Protein via Intermolecular Epitope Spreading
Authors: Deshmukh Umesh S. , Bagavant Harini , Sim Davis , Pidiyar Vyankatesh , Fu Shu Man 
Published: April 2014

Abstract
Autoantibody response against the small nuclear ribonucleoprotein (snRNP) complex is a characteristic feature of systemic lupus erythematosus. The current investigation was undertaken to determine whether activation of SmD-reactive T cells by synthetic peptides harboring T cell epitopes can initiate a B cell epitope spreading cascade within the snRNP complex. T cell epitopes on SmD were mapped in A/J mice and were localized to three regions on SmD, within aa 26–55, 52–69, and 86–115. Immunization with synthetic peptides SmD31–45, SmD52–66, and SmD91–110 induced T and B cell responses to the peptides, with SmD31–45 inducing the strongest response. However, only SmD52–66 immunization induced T cells capable of reacting with SmD. Analysis of sera by immunoprecipitation assays showed that intermolecular B cell epitope spreading to U1RNA-associated A ribonucleoprotein and SmB was consistently observed only in the SmD52–66-immunized mice. Surprisingly, in these mice, Ab responses to SmD were at low levels and transient. In addition, the sera did not react with other regions on SmD, indicating a lack of intramolecular B cell epitope spreading within SmD. Our study demonstrates that T cell responses to dominant epitope on a protein within a multiantigenic complex are capable of inducing B cell responses to other proteins within the complex. This effect can happen without generating a good Ab response to the protein from which the T epitope was derived. Thus caution must be taken in the identification of Ags responsible for initiating autoimmune responses based solely on serological analysis of patients and animals with systemic autoimmune disorders.
Deficient CD4+CD25high T Regulatory Cell Function in Patients with Active Systemic Lupus Erythematosus
Authors: Valencia Xavier , Yarboro Cheryl , Illei Gabor , Lipsky Peter E. 
Published: April 2014

Abstract
CD4+CD25+ T regulatory cells (Tregs) play an essential role in maintaining immunologic homeostasis and preventing autoimmunity. Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by a loss of tolerance to nuclear components. We hypothesized that altered function of CD4+CD25high Tregs might play a role in the breakdown of immunologic self-tolerance in patients with SLE. In this study, we report a significant decrease in the suppressive function of CD4+CD25high Tregs from peripheral blood of patients with active SLE as compared with normal donors and patients with inactive SLE. Notably, CD4+CD25high Tregs isolated from patients with active SLE expressed reduced levels of FoxP3 mRNA and protein and poorly suppressed the proliferation and cytokine secretion of CD4+ effector T cells in vitro. In contrast, the expression of FoxP3 mRNA and protein and in vitro suppression of the proliferation of CD4+ effector T cells by Tregs isolated from inactive SLE patients, was comparable to that of normal individuals. In vitro activation of CD4+CD25high Tregs from patients with active SLE increased FoxP3 mRNA and protein expression and restored their suppressive function. These data are the first to demonstrate a reversible defect in CD4+CD25high Treg function in patients with active SLE, and suggest that strategies to enhance the function of these cells might benefit patients with this autoimmune disease.
The JAK-STAT Signaling Pathway: Input and Output Integration
Authors: Murray Peter J. 
Published: April 2014

Abstract
Universal and essential to cytokine receptor signaling, the JAK-STAT pathway is one of the best understood signal transduction cascades. Almost 40 cytokine receptors signal through combinations of four JAK and seven STAT family members, suggesting commonality across the JAK-STAT signaling system. Despite intense study, there remain substantial gaps in understanding how the cascades are activated and regulated. Using the examples of the IL-6 and IL-10 receptors, I will discuss how diverse outcomes in gene expression result from regulatory events that effect the JAK1-STAT3 pathway, common to both receptors. I also consider receptor preferences by different STATs and interpretive problems in the use of STAT-deficient cells and mice. Finally, I consider how the suppressor of cytokine signaling (SOCS) proteins regulate the quality and quantity of STAT signals from cytokine receptors. New data suggests that SOCS proteins introduce additional diversity into the JAK-STAT pathway by adjusting the output of activated STATs that alters downstream gene activation.