bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphoinositide 3-Kinase and Akt Occupy Central Roles in Inflammatory Responses of Toll-Like Receptor 2-Stimulated Neutrophils
Authors: Strassheim Derek , Asehnoune Karim , Park Jong-Sung , Kim Jae-Yeol , He Qianbin , Richter Donald , Kuhn Katherine , Mitra Sanchayita , Abraham Edward 
Published: April 2014

Abstract
Neutrophils are critical initiators and effectors of the innate immune system and express Toll-like receptor 2 (TLR2) and TLR4. Although signaling through pathways involving phosphoinositide 3-kinase (PI3-K) and the downstream kinase Akt (protein kinase B) plays a central role in modulating neutrophil chemotaxis and superoxide generation in response to engagement of G protein-coupled receptors, the importance of these kinases in affecting inflammatory responses of neutrophils stimulated through TLR2 has not been examined. In these experiments, we found activation of Akt in neutrophils stimulated with the TLR2-specific ligands peptidoglycan and the lipopeptide tri-palmitoyl-S-glyceryl-Cys-Ser-(Lys)4 that occurred earlier and was of greater magnitude than that present after exposure to the TLR4 agonist LPS. The release of the proinflammatory mediators TNF-α and macrophage inflammatory protein-2 was inhibited in a dose-dependent manner by PI3-K blockade. The IC50 for inhibition of peptidoglycan-stimulated Akt activation and macrophage inflammatory protein-2 release correlated closely, indicating linkage of these two events. PI3-K blockade did not inhibit nuclear translocation of NF-κB, but did prevent Ser536 phosphorylation of the p65 subunit of NF-κB, an event required for maximal transcriptional activity of NF-κB. Inhibition of PI3-K also prevented activation of p38 mitogen-activated protein kinase and extracellular receptor-activated kinase 1/2 in TLR2-stimulated neutrophils. These results demonstrate that the PI3-K-Akt axis occupies a central role in TLR2-induced activation of neutrophils.
Regulation of Postsurgical Fibrosis by the Programmed Death-1 Inhibitory Pathway
Authors: Holsti Matthew A. , Chitnis Tanuja , Panzo Ronald J. , Bronson Roderick T. , Yagita Hideo , Sayegh Mohamed H. , Tzianabos Arthur O. 
Published: April 2014

Abstract
Surgical adhesions are a common and often severe complication of abdominal or pelvic injury that cause pelvic pain, bowel obstruction, and infertility in women. Current treatments are of limited effectiveness because little is known about the cellular and subcellular processes underlying adhesiogenesis. Recently, we showed that Th1 αβ CD4+ T cells mediate the pathogenesis of adhesion formation in a rodent model of this disease process. In this study, we demonstrate that in mice these T cells home directly to the site of surgically induced adhesions and control local chemokine production in a manner dependent on the CD28 T cell costimulatory pathway. Conversely, the inhibitory programmed death-1 pathway plays a central role in limiting adhesiogenesis, as programmed death-1 blockade was associated with increased T cell infiltration, chemokine production, and a concomitant exacerbation of disease. Our results reveal for the first time that the development of postsurgical fibrosis is under the tight control of positive and negative T cell costimulation, and suggest that targeting these pathways may provide promising therapies for the prevention of adhesion formation.
Lymphomagenesis, Hydronephrosis, and Autoantibodies Result from Dysregulation of IL-9 and Are Differentially Dependent on Th2 Cytokines
Authors: Lauder Angus J. , Jolin Helen E. , Smith Philippa , van den Berg José G. , Jones Alison , Wisden William , Smith Kenneth G. C. , Dasvarma Ayan , Fallon Padraic G. , McKenzie Andrew N. J. 
Published: April 2014

Abstract
Interleukin-9 is an immunoregulatory cytokine implicated in the development of asthma and allergy. To investigate the role of IL-9 in vivo, we have generated transgenic mice in which IL-9 is expressed from its own promoter. Strikingly, overexpression of IL-9 resulted in premature mortality associated with a complex phenotype characterized by the development of autoantibodies, hydronephrosis, and T cell lymphoma. By intercrossing IL-9 transgenic mice with a panel of Th2 cytokine-deficient mice, we demonstrate that these disorders represent distinct phenotypes that can be dissociated by their differential dependence on Th2 cytokines. Autoantibody production was ablated in IL-9 transgenic animals with a combined absence of IL-4, IL-5, and IL-13, coincident with a reduction in peritoneal B-1 cells. Hydronephrosis arose in 75% of IL-9 transgenic animals and was dependent on the presence of IL-4 and IL-13. In contrast, T cell lymphomas developed independently of the other Th2 cytokines, with the generation of rapidly proliferating CD8+ or CD4+CD8+ T cell clones that arose in the thymus before infiltrating both lymphoid and nonlymphoid tissues. Our data highlight potentially important new roles for IL-9, through its regulation of downstream Th2 effector cytokines, in autoantibody production and in hydronephrosis.
B Cell Positive Selection: Road Map to the Primary Repertoire?
Authors: Cancro Michael P. , Kearney John F. 
Published: April 2014

Abstract
Accumulating evidence indicates that positive selection events mediate differentiation, lineage commitment, and longevity of B lymphocytes. The BCR plays a central role, dictating the likelihood that newly formed cells will complete maturation, as well as whether cells persist within mature pools. Competition among B cells for limited, life span-promoting resources, which include self-ligands, lineage-specific cytokines, and innate receptor ligands, underlie these selective processes. Together, these observations suggest that positive selection is a critical feature in the establishment and maintenance of all lymphocyte pools, prompting re-evaluation of the underlying biological rationale for this process.
The Diabetes Susceptibility Locus Idd5.1 on Mouse Chromosome 1 Regulates ICOS Expression and Modulates Murine Experimental Autoimmune Encephalomyelitis
Authors: Greve Bernhard , Vijayakrishnan Lalitha , Kubal Aarup , Sobel Raymond A. , Peterson Laurence B. , Wicker Linda S. , Kuchroo Vijay K. 
Published: April 2014

Abstract
Linkage analysis and congenic mapping in NOD mice have identified a susceptibility locus for type 1 diabetes, Idd5.1 on mouse chromosome 1, which includes the Ctla4 and Icos genes. Besides type 1 diabetes, numerous autoimmune diseases have been mapped to a syntenic region on human chromosome 2q33. In this study we determined how the costimulatory molecules encoded by these genes contribute to the immunopathogenesis of experimental autoimmune encephalomyelitis (EAE). When we compared levels of expression of costimulatory molecules on T cells, we found higher ICOS and lower full-length CTLA-4 expression on activated NOD T cells compared with C57BL/6 (B6) and C57BL/10 (B10) T cells. Using NOD.B10 Idd5 congenic strains, we determined that a 2.1-Mb region controls the observed expression differences of ICOS. Although Idd5.1 congenic mice are resistant to diabetes, we found them more susceptible to myelin oligodendrocyte glycoprotein 35–55-induced EAE compared with NOD mice. Our data demonstrate that higher ICOS expression correlates with more IL-10 production by NOD-derived T cells, and this may be responsible for the less severe EAE in NOD mice compared with Idd5.1 congenic mice. Paradoxically, alleles at the Idd5.1 locus have opposite effects on two autoimmune diseases, diabetes and EAE. This may reflect differential roles for costimulatory pathways in inducing autoimmune responses depending upon the origin (tissue) of the target Ag.
Fine Mapping, Gene Content, Comparative Sequencing, and Expression Analyses SupportCtla4andNramp1as Candidates forIdd5.1andIdd5.2in the Nonobese Diabetic Mouse
Authors: Wicker Linda S. , Chamberlain Giselle , Hunter Kara , Rainbow Dan , Howlett Sarah , Tiffen Paul , Clark Jan , Gonzalez-Munoz Andrea , Cumiskey Anne Marie , Rosa Raymond L. , Howson Joanna M. , Smink Luc J. , Kingsnorth Amanda , Lyons Paul A. , Gregory Simon , Rogers Jane , Todd John A. , Peterson Laurence B. 
Published: April 2014

AbstractAt least two loci that determine susceptibility to type 1 diabetes in the NOD mouse have been mapped to chromosome 1, Idd5.1 (insulin-dependent diabetes 5.1) and Idd5.2. In this study, using a series of novel NOD.B10 congenic strains, Idd5.1 has been defined to a 2.1-Mb region containing only four genes, Ctla4, Icos, Als2cr19, and Nrp2 (neuropilin-2), thereby excluding a major candidate gene, Cd28. Genomic sequence comparison of the two functional candidate genes, Ctla4 and Icos, from the B6 (resistant at Idd5.1) and the NOD (susceptible at Idd5.1) strains revealed 62 single nucleotide polymorphisms (SNPs), only two of which were in coding regions. One of these coding SNPs, base 77 of Ctla4 exon 2, is a synonymous SNP and has been correlated previously with type 1 diabetes susceptibility and differential expression of a CTLA-4 isoform. Additional expression studies in this work support the hypothesis that this SNP in exon 2 is the genetic variation causing the biological effects of Idd5.1. Analysis of additional congenic strains has also localized Idd5.2 to a small region (1.52 Mb) of chromosome 1, but in contrast to the Idd5.1 interval, Idd5.2 contains at least 45 genes. Notably, the Idd5.2 region still includes the functionally polymorphic Nramp1 gene. Future experiments to test the identity of Idd5.1 and Idd5.2 as Ctla4 and Nramp1, respectively, can now be justified using approaches to specifically alter or mimic the candidate causative SNPs.
Mouse Complement Receptor-Related Gene y/p65-Neutralized Tumor Vaccine Induces Antitumor Activity In Vivo
Authors: Ohta Rieko , Kondor Natalie , Dohi Natsuki , Tomlinson Stephen , Imai Masaki , Holers V. Michael , Okada Hidechika , Okada Noriko 
Published: April 2014

Abstract
Two mouse tumor cell lines, Meth A (BALB/c mouse-derived fibrosarcoma) and MM46 (C3H/He mouse-derived mammary tumor), were shown to express high levels of complement receptor-related gene y/p65 (Crry/p65), a membrane-bound complement-regulatory protein. Inhibiting the complement-regulatory activity of Crry/p65 with mAb 5D5 induced high levels of C3 deposition on in vivo tumor-derived Meth A and MM46 cells. To determine the effect of Crry/p65 blockade and increased C3 deposition on in vivo tumor growth, Meth A and MM46 cells were treated with 5D5 mAb and injected into BALB/c and C3H/He mice, respectively. Pretreating MM46 cells with 5D5 mAb significantly suppressed their tumorigenicity when injected s.c. Pretreatment with 5D5 mAb had a modest effect on Meth A s.c. tumor growth. Because complement is involved in the induction of an immune response, we investigated the effect of Crry/p65 blockade and increased C3 deposition on the immunogenicity of the tumor cells in a vaccination protocol. Vaccination of mice with irradiated Meth A cells pretreated with 5D5 mAb protected mice from subsequent challenge. In contrast, vaccination with irradiated Meth A cells without pretreatment was not protective. Survival was correlated with a high titer IgM response and specific CTL activity. These data demonstrate that the functional inhibition of Crry/p65 on tumor cells affects tumor growth and immunogenicity, and that the complement deposition resulting from this inhibition can act in concert with antitumor effector mechanisms to elicit potent antitumor immunity in vivo.
Different Costimulatory and Growth Factor Requirements for CD4+ and CD8+ T Cell-Mediated Rejection
Authors: Vu Minh Diem , Amanullah Farhana , Li Yongsheng , Demirci Gulcin , Sayegh Mohamed H. , Li Xian Chang 
Published: April 2014

Abstract
Costimulatory signals and growth factor signals play a key role in commanding T cell activation and T cell effector function. However, how costimulatory signals and growth factor signals interact and integrate into the activation program of CD4+ and CD8+ T cells during the allograft response remains poorly defined. In the present study we found that either CD4- or CD8-deficient mice can vigorously reject the skin allografts. Blocking rapamycin-sensitive growth factor signals produced long term skin allograft survival in CD4-deficient mice (mean survival time, &gt;120 days), but not in CD8-deficient mice (mean survival time, 20 days). Analysis of CFSE-labeled cells proliferating in the allogeneic hosts revealed that clonal expansion of CD4+ T cells in vivo was more resistant to growth factor blockade than that of CD8+ T cells. However, blockade or genetic absence of CD28/CD154 costimulatory molecules rendered CD4+ T cell-mediated rejection sensitive to rapamycin, and long term skin allograft survival can be readily induced by rapamycin in the absence of CD28/CD154 signals (&gt;100 days). Furthermore, blocking OX40 costimulation induced long term skin allograft survival in CD4-deficient mice and CD8-deficient mice when both CD28 and CD154 were transiently blocked. We conclude that CD4+ and CD8+ T cells exhibit distinct sensitivity to growth factor blockade in transplant rejection, and CD28/CD154-independent rejection is sensitive to rapamycin and appears to be supported by OX40 costimulation.
Antigen Distribution Drives Programmed Antitumor CD8 Cell Migration and Determines Its Efficiency
Authors: Boissonnas Alexandre , Combadiere Christophe , Lavergne Elise , Maho Maud , Blanc Catherine , Debré Patrice , Combadiere Behazine 
Published: April 2014

Abstract
Understanding both the role of tumor Ag in CD8 cell differentiation and the reasons that CD8 cells may work inefficiently is crucial for therapeutic approaches in cancer. We studied OT-1 CD8 cell responses in vivo in a differential Ag-distribution model that used EG-7, the EL-4 thymoma transfected with OVA. On their initial Ag encounter, OT-1 CD8 cells underwent programmed expansion in the lymph nodes, where they acquired the ability to migrate to the encapsulated tumor site after ≥4 divisions, without continuous antigenic stimulation. This short antigenic stimulation was sufficient to induce the migration differentiation program, which included modulation of chemokine receptor mRNA expression and down-regulation of CD62L. Moreover, Ag quantity determined the behavior of the OT-1 CD8 cells, including their effector functions and sensitivity to apoptosis. Thus, the initial Ag encounter drives the programmed cell migration potencies, but neither effector functions nor cell death can occur without continuous TCR triggering.
Delayed and Restricted Expression Limits Putative Instructional Opportunities of Vγ1.1/Vγ2 γδ TCR in αβ/γδ Lineage Choice in the Thymus
Authors: Krotkova Anna , Smith Emma , Nerz Gabi , Falk Ingrid , Eichmann Klaus 
Published: April 2014

Abstract
Development of αβ and γδ T cells depends on productive rearrangement of the appropriate TCR genes and their subsequent expression as proteins. TCRβ and TCRγδ proteins first appear in DN3 and DN4 thymocytes, respectively. So far, it is not clear whether this is due to a delayed expression of TCRγδ proteins or to a more rapid progression to DN4 of thymocytes expressing TCRγδ. The answer to this question bears on the distinction between instructive and stochastic models of αβ/γδ lineage decision. To study this question, we first monitored initial TCR protein expression in wild-type and TCR transgenic mice in reaggregate thymic organ cultures. A TCRβ transgene was expressed in nearly all DN3 and DN4 cells, accelerated DN3 to DN4 transition, and strongly diminished the number of cells that express TCRγδ proteins. In contrast, TCRγδ transgenes were expressed only in a fraction of DN4 cells, did not accelerate DN3 to DN4 transition, and did not reduce the number of DN4 cells expressing TCRβ proteins. The TCRβ transgene partially inhibited endogenous TCRγ rearrangements, whereas the TCRγδ transgenes did not inhibit endogenous TCRβ rearrangements. Second, we analyzed frequencies of productive TCRβ and TCRγδ V(D)J junctions in DN3 and DN4 subsets. Most importantly, frequencies of productive TCRγδ rearrangements (Vδ5, Vγ1.1, and Vγ2) appeared unselected in DN3. The results suggest a late and restricted expression of the corresponding γδTCR, severely limiting their putative instructional opportunities in αβ/γδ divergence.
Structural and Functional Characterization of Complement C4 and C1s-Like Molecules in Teleost Fish: Insights into the Evolution of Classical and Alternative Pathways
Authors: Boshra Hani , Gelman Andrew E. , Sunyer J. Oriol 
Published: April 2014

Abstract
There is growing evidence that certain components of complement systems in lower vertebrates are promiscuous in their modes of activation through the classical or alternative pathways. To better understand the evolution of the classical pathway, we have evaluated the degree of functional diversification of key components of the classical and alternative pathways in rainbow trout, an evolutionarily relevant teleost species. Trout C4 was purified in two distinct forms (C4-1 and C4-2), both exhibiting the presence of a thioester bond at the cDNA and protein levels. C4-1 and C4-2 bound in a similar manner to trout IgM-sensitized sheep erythrocytes in the presence of Ca2+/Mg2+, and both C4 molecules equally restored the classical pathway-mediated hemolytic activity of serum depleted of C3 and C4. Reconstitution of activity was dependent on the presence of both C3-1 and C4-1/C4-2 and on the presence of IgM bound to the sheep erythrocytes. A C1s-like molecule was shown to cleave specifically purified C4-1 and C4-2 into C4b, while failing to cleave trout C3 molecules. The C1s preparation was unable to cleave trout factor B/C2 when added in the presence of C3b or C4b molecules. Our results show a striking conservation of the mode of activation of the classical pathway. We also show that functional interchange between components of the classical and alternative pathway in teleosts is more restricted than was anticipated. These data suggest that functional diversification between the two pathways must have occurred shortly after the gene duplication that gave rise to the earliest classical pathway molecules.
Serine Residues 286, 288, and 293 within the CIITA: A Mechanism for Down-Regulating CIITA Activity through Phosphorylation
Authors: Greer Susanna F. , Harton Jonathan A. , Linhoff Michael W. , Janczak Christin A. , Ting Jenny P.-Y. , Cressman Drew E. 
Published: April 2014

Abstract
CIITA is the primary factor activating the expression of the class II MHC genes necessary for the exogenous pathway of Ag processing and presentation. Strict control of CIITA is necessary to regulate MHC class II gene expression and induction of an immune response. We show in this study that the nuclear localized form of CIITA is a predominantly phosphorylated form of the protein, whereas cytoplasmic CIITA is predominantly unphosphorylated. Novel phosphorylation sites were determined to be located within a region that contains serine residues 286, 288, and 293. Double mutations of these residues increased nuclear CIITA, indicating that these sites are not required for nuclear import. CIITA-bearing mutations of these serine residues significantly increased endogenous MHC class II expression, but did not significantly enhance trans-activation from a MHC class II promoter, indicating that these phosphorylation sites may be important for gene activation from intact chromatin rather than artificial plasmid-based promoters. These data suggest a model for CIITA function in which phosphorylation of these specific sites in CIITA in the nucleus serves to down-regulate CIITA activity.
Generation of Peptide Mimics of the Epitope Recognized by Trastuzumab on the Oncogenic Protein Her-2/neu
Authors: Riemer Angelika B. , Klinger Markus , Wagner Stefan , Bernhaus Astrid , Mazzucchelli Luca , Pehamberger Hubert , Scheiner Otto , Zielinski Christoph C. , Jensen-Jarolim Erika 
Published: April 2014

Abstract
Immunizations with the oncogenic protein Her-2/neu elicit Abs exerting diverse biological effects--depending on epitope specificity, tumor growth may be inhibited or enhanced. Trastuzumab (herceptin) is a growth-inhibitory humanized monoclonal anti-Her-2/neu Ab, currently used for passive immunotherapy in the treatment of breast cancer. However, Ab therapies are expensive and have to be repeatedly administered for long periods of time. In contrast, active immunizations produce ongoing immune responses. Therefore, the study aims to generate peptide mimics of the epitope recognized by trastuzumab for vaccine formulation, ensuring the subsequent induction of tumor growth inhibitory Abs. We used the phage display technique to generate epitope mimics, mimotopes, complementing the screening Ab trastuzumab. Five candidate mimotopes were isolated from a constrained 10 mer library. These peptides were specifically recognized by trastuzumab, and showed distinctive mimicry with Her-2/neu in two experimental setups. Subsequently, immunogenicity of a selected mimotope was examined in BALB/c mice. Immunizations with a synthetic mimotope conjugated to tetanus toxoid resulted in Abs recognizing Her-2/neu in a blotted cell lysate as well as on the SK-BR-3 cell surface. Analogous to trastuzumab, the induced Abs caused internalization of the receptor from the cell surface to endosomal vesicles. These results indicate that the selected mimotopes are suitable for formulation of a breast cancer vaccine because the resulting Abs show similar biological features as trastuzumab.
A Hierarchy of Nuclear Localization Signals Governs the Import of the Regulatory Factor X Complex Subunits and MHC Class II Expression
Authors: Nagarajan Uma M. , Long Alyssa B. , Harreman Michelle T. , Corbett Anita H. , Boss Jeremy M. 
Published: April 2014

Abstract
Comprised of RFX5, RFXAP, and RFX-B/ANK, the regulatory factor X (RFX) complex is an obligate transcription factor required for the expression of MHC class II genes. RFX functions by binding to the conserved X1 box sequence located upstream of all MHC class II genes. Using a mutagenesis scheme and a yeast heterologous reporter system, the mechanism by which the RFX complex is transported into the nucleus was examined. The results have identified specific nuclear localization signals (NLS) in both RFX5 and RFXAP that direct the nuclear translocation and expression of MHC class II genes. Additionally, a nuclear export signal was identified in the N terminus of RFXAP. RFX-B was poorly localized to the nucleus, and no specific NLS was identified. Whereas RFX5 could import an RFXAP NLS mutant into the nucleus, it had no effect on the import of RFX-B. The results suggest that although RFX5 and RFXAP could assemble before nuclear import, RFX-B association with the complex does not take place until after the subunits enter the nucleus. The identification of nuclear import and export sites on RFX molecules provides potential targets to modulate MHC class II expression.