bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Targeted Inhibitor of the Alternative Pathway of Complement and Its Therapeutic Application in Ischemia/Reperfusion Injury
Authors: Huang Yuxiang , Qiao Fei , Atkinson Carl , Holers V. Michael , Tomlinson Stephen 
Published: April 2014

Abstract
Bioavailability and therapeutic efficacy of soluble Crry, a mouse inhibitor of all complement activation pathways, is significantly enhanced when linked to a fragment of complement receptor 2 (CR2), a receptor that targets C3 activation products. In this study, we characterize alternative pathway-specific inhibitors consisting of a single or dimeric N-terminal region of mouse factor H (fH; short consensus repeats 1–5) linked to the same CR2 fragment (CR2-fH and CR2-fHfH). Both CR2-fH and CR2-fHfH were highly effective at inhibiting the alternative pathway in vitro and demonstrated a higher specific activity than CR2-Crry. CR2-fH was also more effective than endogenous serum fH in blocking target deposition of C3. Target binding and complement inhibitory activity of CR2-fH/CR2-fHfH was dependent on CR2- and C3-mediated interactions. The alternative pathway of complement plays a role in intestine ischemia/reperfusion injury. However, serum fH fails to provide protection against intestine ischemia/reperfusion injury although it can bind to and provide cell surfaces with protection from complement and is present in plasma at a high concentration. In a mouse model, CR2-fH and CR2-fHfH provided complete protection from local (intestine) and remote (lung) injury. CR2-fH targeted to the site of local injury and greatly reduced levels of tissue C3 deposition. Thus, the targeting mechanism significantly enhances alternative pathway-specific complement inhibitory activity of the N-terminal domain of fH and has the potential to reduce side effects that may be associated with systemic complement blockade. The data further indicate alternative pathway dependence for local and remote injury following intestinal ischemia/reperfusion in a clinically relevant therapeutic paradigm.
In Vivo BLyS/BAFF Neutralization Ameliorates Islet-Directed Autoimmunity in Nonobese Diabetic Mice
Authors: Zekavat Ghazal , Rostami Susan Y. , Badkerhanian Armen , Parsons Ronald F. , Koeberlein Brigitte , Yu Ming , Ward Christopher D. , Migone Thi-Sau , Yu Liping , Eisenbarth George S. , Cancro Michael P. , Naji Ali , Noorchashm Hooman 
Published: April 2014

AbstractB lymphocytes are required for the pathogenesis of autoimmune diabetes in NOD mice. Previous studies established that a lymphopenic transitional (TR) B cell compartment reduces the competitive constraint on the entry of newly emerging TR B cells into the splenic follicle (FO), thereby disrupting a peripheral negative selection checkpoint in NOD mice. Thus, development of clinically feasible immunotherapeutic approaches for restoration of appropriate negative selection is essential for the prevention of anti-islet autoimmunity. In this study we hypothesized that in vivo neutralization of the B lymphocyte stimulator (BLyS/BAFF) may enhance the stringency of TR→FO selection by increasing TR B cell competition for follicular entry in NOD mice. This study demonstrated that in vivo BLyS neutralization therapy leads to the depletion of follicular and marginal zone B lymphocytes. Long-term in vivo BLyS neutralization caused an increased TR:FO B cell ratio in the periphery indicating a relative resistance to follicular entry. Moreover, in vivo BLyS neutralization: 1) restored negative selection at the TR→FO checkpoint, 2) abrogated serum insulin autoantibodies, 3) reduced the severity of islet inflammation, 4) significantly reduced the incidence of spontaneous diabetes, 5) arrested the terminal stages of islet cell destruction, and 6) disrupted CD4 T cell activation in NOD mice. Overall, this study demonstrates the efficacy of B lymphocyte-directed therapy via in vivo BLyS neutralization for the prevention of autoimmune diabetes.
Differential Expression and Molecular Associations of Syk in Systemic Lupus Erythematosus T Cells
Authors: Krishnan Sandeep , Juang Yuang-Taung , Chowdhury Bhabadeb , Magilavy Abigail , Fisher Carolyn U. , Nguyen Hang , Nambiar Madhusoodana P. , Kyttaris Vasileios , Weinstein Arthur , Bahjat Rena , Pine Polly , Rus Violeta , Tsokos George C. 
Published: April 2014

Abstract
Diminished expression of TCR ζ and reciprocal up-regulation and association of FcRγ with the TCR/CD3 complex is a hallmark of systemic lupus erythematosus (SLE) T cells. In this study we explored whether differential molecular associations of the spleen tyrosine kinase Syk that preferentially binds to FcRγ contribute to pathological amplification of signals downstream of this “rewired TCR” in SLE. We detected higher amounts of Syk expression and activity in SLE compared with normal T cells. Selective inhibition of the activity of Syk reduced the strength of TCR-induced calcium responses and slowed the rapid kinetics of actin polymerization exclusively in SLE T cells. Syk and ZAP-70 also associated differently with key molecules involved in cytoskeletal and calcium signaling in SLE T cells. Thus, while Vav-1 and LAT preferentially bound to Syk, phospholipase C-γ1 bound to both Syk and ZAP-70. Our results show that differential associations of Syk family kinases contribute to the enhanced TCR-induced signaling responses in SLE T cells. Thus, we propose molecular targeting of Syk as a measure to control abnormal T cell responses in SLE.
Cutting Edge: Critical Role for Mesothelial Cells in Necrosis-Induced Inflammation through the Recognition of IL-1α Released from Dying Cells
Authors: Eigenbrod Tatjana , Park Jong-Hwan , Harder Jürgen , Iwakura Yoichiro , Núñez Gabriel 
Published: April 2014

AbstractEndogenous danger signals released from necrotic cells are thought to be sensed by phagocytes leading to secretion of IL-1α and neutrophilic recruitment. However, the mechanisms for IL-1α production and IL-1α-mediated sterile inflammation remain poorly understood. We report here that necrotic cell extracts elicited little secretion of CXCL1 and IL-6 from macrophages but robust production in mesothelial cells. The induction of CXCL1 as well as activation of NF-κB and MAPKs by cytosolic extracts required the presence of IL-1α in the necrotic cell. Conversely, expression of IL-1R and MyD88 but not IL-1α, RICK, TLR2, TLR4, TRIF, or inflammasome components in mesothelial cells was critical for the production of CXCL1. Furthermore, IL-1α was critical to induce the recruitment of neutrophils in the peritoneal cavity via CXCR2. These studies show that IL-1α is a key danger signal released from necrotic cells to trigger CXCL1 secretion and recruitment of neutrophils via IL-1R/MyD88 on neighboring mesothelial cells.
γ-Aminobutyric Acid Transporter 1 Negatively Regulates T Cell-Mediated Immune Responses and Ameliorates Autoimmune Inflammation in the CNS
Authors: Wang Ying , Feng Dechun , Liu Guoxiang , Luo Qingqiong , Xu Yan , Lin Shuting , Fei Jian , Xu Lingyun 
Published: April 2014

Abstract
γ-aminobutyric acid (GABA) is the major inhibitory neurotransmitter of the CNS, and GABA transporter 1 (GAT-1) is critical in maintaining a GABA reservoir and associated functions. The wide expression of GAT-1 in the CNS prompted us to explore its role in neuroimmunological disorders. In mice induced with experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis, we found that the expression levels of GAT-1 mRNA and protein in spinal cord were greatly suppressed as compared with those in naive mice and irrelevant Ag-immunized mice. Therefore, we induced EAE in GAT-1−/− mice and found that the disease was significantly aggravated and was accompanied by some nonclassic EAE signs. Mononuclear cells from GAT-1−/− mice with EAE showed much higher Ag-specific proliferative responses. Proinflammatory cytokine production in these mice was also greatly up-regulated. Further studies revealed that GAT-1 deficiency induced vigorous immune responses by enhancing IκB kinase phosphorylation and NF-κB-DNA binding activity, as well as strengthening the T-bet-STAT1 circuit signaling pathway. Finally, we found that GAT-1 was expressed only on activated T cells primed with Ags, but not on B cells or macrophages. These findings indicate that GAT-1 is a critical modulator in T cell-mediated immune responses and in EAE pathogenesis.
Inhibition of Tumor Growth by NK1.1+ Cells and CD8+ T Cells Activated by IL-15 through Receptor β/Common γ Signaling in trans
Authors: Rowley Jesse , Monie Archana , Hung Chien-Fu , Wu T.-C. 
Published: April 2014

Abstract
IL-15 is an important cytokine involved in the survival and function of CD8+ T cells and NK cells. IL-15 can be presented by IL-15Rα (IL-15RA) to bind with the shared IL-2/IL-15Rβ and common γ-chains, which activate signaling pathways on NK cells and CD8+ T cells. In the present study, we characterized the function of trans-presented IL-15 on NK cells and CD8+ T cells using TC-1 tumor cells transduced with a retrovirus encoding IL-15 linked to IL-15RA (IL-15/IL-15RA). We demonstrated that the expression of IL-15/IL-15RA on TC-1 cells led to increased percentages of tumor-infiltrating NK cells, NKT cells, and CD8+ T cells, resulting in the inhibition of tumor growth in challenged mice. Additionally, in vivo Ab depletion experiments demonstrated that NK1.1+ cells and CD8+ T cells were important in this inhibition of tumor growth. Furthermore, this accumulation of immune cells and inhibition of tumor growth was abolished by a single amino acid mutation in the common γ-chain binding site on IL-15. We also observed that IL-15/IL-15RA-transduced TC-1 cells led to the activation of STAT5 in NK and CD8+ T cells in trans, which was abolished in the mutated IL-15/IL-15RA-transduced TC-1 cells. Taken together, our data suggest that common γ-chain binding-dependent activation of the shared IL-15/IL-2Rβ/common γ signaling pathway may play an important role in the activation of NK cells and CD8+ T cells, resulting in IL-15/IL-15RA trans-presentation-mediated inhibition of tumor growth.
A Novel ICOS-Independent, but CD28- and SAP-Dependent, Pathway of T Cell-Dependent, Polysaccharide-Specific Humoral Immunity in Response to IntactStreptococcus pneumoniaeversus Pneumococcal Conjugate Vaccine
Authors: Chen Quanyi , Cannons Jennifer L. , Paton James C. , Akiba Hisaya , Schwartzberg Pamela L. , Snapper Clifford M. 
Published: April 2014

AbstractPolysaccharide (PS)- and protein-specific murine IgG responses to intact Streptococcus pneumoniae (Pn) are both dependent on CD4+ T cell help, B7-dependent costimulation, and CD40/CD40 ligand interactions. However, the primary PS-specific, relative to protein-specific, IgG response terminates more rapidly, requires a shorter period of T cell help and B7-dependent costimulation, and fails to generate memory. In light of the critical role for ICOS/ICOS ligand interactions in sustaining T cell-dependent Ig responses and promoting germinal center reactions, we hypothesized that this interaction was nonessential for PS-specific IgG responses to Pn. We now demonstrate that ICOS−/−, relative to wild-type, mice elicit a normal PS-specific IgG isotype response to Pn, despite marked inhibition of both the primary and secondary IgG anti-protein (i.e., PspA, PspC, and PsaA) response. A blocking anti-ICOS ligand mAb injected during primary Pn immunization inhibits both the primary anti-protein response and the generation of protein-specific memory, but has no effect when injected during secondary immunization. In contrast to Pn, both PS- and protein-specific IgG responses to a pneumococcal conjugate vaccine are inhibited in ICOS−/− mice. ICOS−/− mice immunized with intact Pn or conjugate exhibit nearly complete abrogation in germinal center formation. Finally, although mice that lack the adaptor molecule SAP (SLAM-associated protein) resemble ICOS−/− mice (and can exhibit decreased ICOS expression), we observe that the PS-specific, as well as protein-specific, IgG responses to both Pn and conjugate are markedly defective in SAP−/− mice. These data define a novel T cell-, SAP-, and B7-dependent, but ICOS-independent, extrafollicular pathway of Ig induction.
Improved Efficacy of a Tolerizing DNA Vaccine for Reversal of Hyperglycemia through Enhancement of Gene Expression and Localization to Intracellular Sites
Authors: Solvason Nanette , Lou Ya-Ping , Peters Wendy , Evans Erica , Martinez Josefina , Ramirez Uriel , Ocampo Andrea , Yun Rui , Ahmad Saira , Liu Edwin , Yu Liping , Eisenbarth George , Leviten Michael , Steinman Lawrence , Garren Hideki 
Published: April 2014

AbstractInsulin is a major target for the autoimmune-mediated destruction of pancreatic β cells during the pathogenesis of type I diabetes. A plasmid DNA vaccine encoding mouse proinsulin II reduced the incidence of diabetes in a mouse model of type I diabetes when administered to hyperglycemic (therapeutic mode) or normoglycemic (prophylactic mode) NOD mice. Therapeutic administration of proinsulin DNA was accompanied by a rapid decrease in the number of insulin-specific IFN-γ-producing T cells, whereas prophylactic treatment was accompanied by enhanced IFN-γ-secreting cells and a decrease in insulin autoantibodies. Adoptive transfer experiments demonstrated that the protection was not mediated by induction of CD25+/CD4+ T regulatory cells. The efficacy of the DNA vaccine was enhanced by increasing the level of expression of the encoded Ag, more frequent dosing, increasing dose level, and localization of the protein product to the intracellular compartment. The efficacy data presented in this study demonstrate that Ag-specific plasmid DNA therapy is a viable strategy for preventing progression of type I diabetes and defines critical parameters of the dosing regime that influences tolerance induction.
Sialic Acid Residues Are Essential for the Anaphylactic Activity of Murine IgG1 Antibodies
Authors: Silva Sandriana R. , Casabuono Adriana , Jacysyn Jacqueline F. , Favoretto Bruna C. , Fernandes Irene , Macedo Mahasti S. , Couto Alicia S. , Faquim-Mauro Eliana L. 
Published: April 2014

AbstractGlycosylation of the Ab molecule is essential for maintaining the functional structure of Fc region and consequently for Ab-mediated effector functions, such as binding to cells or complement system activation. Alterations in the composition of the sugar moiety can dramatically influence Ab activity; however, it is not completely clear how differences in the N-linked oligosaccharide structure impact the biological function of Abs. We have described that murine IgG1 Abs can be separated according to their ability to elicit in vivo anaphylaxis in a fraction of anaphylactic and other of non-anaphylactic molecules. Furthermore, we showed that the N-linked oligosaccharide chain is essential for the structural conformation of the anaphylactic IgG1, the binding to FcγRIII on mast cells, and, consequently, for the ability to mediate anaphylactic reactions. In this study, we evaluated the contribution of individual sugar residues to this biological function. Differences in the glycan composition were observed when we analyzed oligosaccharide chains from anaphylactic or non-anaphylactic IgG1, mainly the presence of more sialic acid and fucose residues in anaphylactic molecules. Interestingly, the enzymatic removal of terminal sialic acid residues in anaphylactic IgG1 resulted in loss of the ability to trigger mast cell degranulation and in vivo anaphylactic reaction, similarly to the deglycosylated IgG1 Ab. In contrast, fucose removal did not affect the anaphylactic function. Therefore, we demonstrated that the ability of murine IgG1 Abs to mediate anaphylaxis is directly dependent on the amount of sialic acid residues associated to the oligosaccharide chain attached to the Fc region of these molecules.
CCR6 Regulates the Migration of Inflammatory and Regulatory T Cells
Authors: Yamazaki Tomohide , Yang Xuexian O. , Chung Yeonseok , Fukunaga Atsushi , Nurieva Roza , Pappu Bhanu , Martin-Orozco Natalia , Kang Hong Soon , Ma Li , Panopoulos Athanasia D. , Craig Suzanne , Watowich Stephanie S. , Jetten Anton M. , Tian Qiang , Dong Chen 
Published: April 2014

Abstract
Th17 and regulatory T (Treg) cells play opposite roles in autoimmune diseases. However, the mechanisms underlying their proper migration to inflammatory tissues are unclear. In this study, we report that these two T cell subsets both express CCR6. CCR6 expression in Th17 cells is regulated by TGF-β and requires two nuclear receptors, RORα and RORγ. Th17 cells also express the CCR6 ligand CCL20, which is induced synergistically by TGF-β and IL-6, which requires STAT3, RORγ and IL-21. Th17 cells, by producing CCL20, promote migration of Th17 and Treg cells in vitro in a CCR6-dependent manner. Lack of CCR6 in Th17 cells reduces the severity of experimental autoimmune encephalomyelitis and Th17 and Treg recruitment into inflammatory tissues. Similarly, CCR6 on Treg cells is also important for their recruitment into inflammatory tissues. Our data indicate an important role of CCR6 in Treg and Th17 cell migration.
Acute Pulmonary Lipopolysaccharide Tolerance Decreases TNF-α without Reducing Neutrophil Recruitment
Authors: Natarajan Sudha , Kim Jiyoun , Remick Daniel G. 
Published: April 2014

Abstract
Pulmonary LPS exposure plays a key role in exacerbation of lung diseases such as chronic obstructive pulmonary disease and asthma. However, little is known about the effects of repeated LPS exposure in the lung microenvironment. We have developed a novel murine model of pulmonary LPS tolerance induced by intratracheal (i.t.) administration of LPS. First, we show that pulmonary LPS exposure does not induce whole-body refractoriness to systemic LPS, because i.t. administration followed by i.p. administration did not decrease plasma TNF-α. However, a local refractory state can be induced with two i.t. LPS exposures. Pulmonary LPS tolerance was induced by i.t. administration of 100 ng LPS at time 0 and 48 h. Nontolerant mice received PBS at time 0 and LPS at 48 h. Bronchoalveolar lavage levels of TNF-α were significantly attenuated in tolerant mice vs nontolerant mice (1597 pg/ml vs 7261 pg/ml). TNF-α mRNA was significantly reduced in bronchoalveolar lavage cells (5-fold) and lung tissue (10-fold). No reduction was seen in neutrophil numbers in the bronchoalveolar lavage fluid, myeloperoxidase activity, or expression of neutrophil chemoattractants CXCL1 and CXCL2, reflecting the specificity of the response. The reduction in TNF-α was accompanied by a significant increase in soluble receptors, TNF-SRI (159 pg/ml vs 206 pg/ml) and TNF-SRII (1366 pg/m vs 2695 pg/ml). In conclusion, pulmonary LPS tolerance results in a specific reduction in TNF-α expression, while the neutrophilic response is unaffected. This response may be a mechanism to limit tissue damage by reducing TNF-α levels, while still maintaining the antimicrobial capacity of the lung.
Preferential Use of DH Reading Frame 2 Alters B Cell Development and Antigen-Specific Antibody Production
Authors: Schelonka Robert L. , Zemlin Michael , Kobayashi Ryoki , Ippolito Gregory C. , Zhuang Yingxin , Gartland G. Larry , Szalai Alex , Fujihashi Kohtaro , Rajewsky Klaus , Schroeder Harry W. 
Published: April 2014

Abstract
All jawed vertebrates limit use of DH reading frames (RFs) that are enriched for hydrophobic amino acids. In BALB/c mice, DFL16.1 RF2 encodes valine and isoleucine. To test whether increased use of RF2 affects B cell function, we examined B cell development and Ab production in mice with an IgH allele (ΔD-DμFS) limited to use of a single, frameshifted DFL61.1 gene segment. We compared the results of these studies to wild-type mice, as well as those previously obtained in mice limited to use of either a single normal DH or a single inverted DH that forces use of arginine in CDR-H3. All three of the mouse strains limited to a single DH produced fewer immature B cells than wild type. However, whereas mice limited to a single normal DH achieved normal B cell numbers in the periphery, mice forced to preferentially use RF2 had reduced numbers of mature B cells in the spleen and bone marrow, mirroring the pattern previously observed in mice enriched for charged CDR-H3s. There were two exceptions. B cells in the mice using RF2 normally populated the marginal zone and peritoneal cavity, whereas mice using inverted RF1 had increased numbers of marginal zone B cells and decreased numbers of B1a cells. When challenged with several T-dependent or T-independent Ags, Ag-specific Ab titers in the mice forced to use RF2 were altered. These findings indicate that B cell development and Ag-specific Ab production can be heavily influenced by the global amino acid content of the CDR-H3 repertoire.
Induction of HIV Transcription by Nef Involves Lck Activation and Protein Kinase Cθ Raft Recruitment Leading to Activation of ERK1/2 but Not NFκB
Authors: Witte Vanessa , Laffert Bernd , Gintschel Patricia , Krautkrämer Ellen , Blume Katja , Fackler Oliver T. , Baur Andreas S. 
Published: April 2014

Abstract
The Nef protein of HIV-1 is a key promoter of disease progression, owing to its dramatic yet ill-defined impact on viral replication. Previously, we have shown that Nef enhances embryonic ectodermal development Tat-mediated transcription in a manner depending on Lck and the cytoplasmic sequestration of the transcriptional repressor embryonic ectodermal development. In this study, we report that Lck is activated by Nef and targets protein kinase Cθ downstream, leading to the translocation of the kinase into membrane microdomains. Although microdomain-localized protein kinase Cθ is thought to induce the transcription factor NFκB, we unexpectedly failed to correlate Nef-induced signaling events with enhanced NFκB activity. Instead, we observed an increase in ERK MAPK activity. We conclude that Nef-mediated signaling cooperates with Nef-induced derepression and supports HIV transcription through an ERK MAPK-dependent, but NFκB-independent, pathway.
Reassessment of the Role of Mut S Homolog 5 in Ig Class Switch Recombination Shows Lack of Involvement in cis- and trans-Switching
Authors: Guikema Jeroen E. J. , Schrader Carol E. , Leus Niek G. J. , Ucher Anna , Linehan Erin K. , Werling Uwe , Edelmann Winfried , Stavnezer Janet 
Published: April 2014

Abstract
When B cells are activated after immunization or infection, they exchange the gene encoding the Ig H chain C region by class switch recombination (CSR). CSR generally occurs by an intrachromosomal deletional recombination within switch (S) region sequences. However, ∼10% of CSR events occur between chromosome homologs (trans- or interallele CSR), suggesting that the homologous chromosomes are aligned during CSR. Because the Mut S homolog 4 (Msh4) and Msh5 bind to Holliday junctions and are required for homologous recombination during meiosis in germ cells, we hypothesized these proteins might be involved in trans-chromosomal CSR (trans-CSR). Indeed, Msh4-Msh5 has recently been suggested to have a role in CSR. However, we find a large variety of alternative splice variants of Msh5 mRNA in splenic B cells rather than the full-length form found in testis. Most of these mRNAs are unlikely to be stable, suggesting that Msh5 might not be functional. Furthermore, we find that msh5 nullizygous B cells undergo CSR normally, have unaltered levels of trans-CSR, normal levels of DNA breaks in the Sμ region, and normal S-S junctions. We also show that the S-S junctions from cis- and trans-CSR events have similar lengths of junctional microhomology, suggesting trans-CSR occurs by nonhomologous end joining as does intrachromosome (cis)-CSR. From these data, we conclude that Msh5 does not participate in CSR.