bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Phylogenetic Analysis of Activation-Induced Deaminase Function
Authors: Ichikawa H. Travis , Sowden Mark P. , Torelli Andrew T. , Bachl Jürgen , Huang Pinwei , Dance Geoffrey S. C. , Marr Shauna H. , Robert Jacques , Wedekind Joseph E. , Smith Harold C. , Bottaro Andrea 
Published: April 2014

Abstract
In mammals, activation-induced deaminase (AID) initiates somatic hypermutation (SHM) and class switch recombination (CSR) of Ig genes. SHM and CSR activities require separate regions within AID. A chromosome region maintenance 1 (CRM1)-dependent nuclear export signal (NES) at the AID C terminus is necessary for CSR, and has been suggested to associate with CSR-specific cofactors. CSR appeared late in AID evolution, during the emergence of land vertebrates from bony fish, which only display SHM. Here, we show that AID from African clawed frog (Xenopus laevis), but not pufferfish (Takifugu rubripes), can induce CSR in AID-deficient mouse B cells, although both are catalytically active in bacteria and mammalian cell systems, albeit at decreased level. Like mammalian AID, Takifugu AID is actively exported from the cell nucleus by CRM1, and the Takifugu NES can substitute for the equivalent region in human AID, indicating that all the CSR-essential NES motif functions evolutionarily predated CSR activity. We also show that fusion of the Takifugu AID catalytic domain to the entire human noncatalytic domain restores activity in mammalian cells, suggesting that AID features mapping within the noncatalytic domain, but outside the NES, influence its function.
B Cells and Dendritic Cells from Vκ8 Light Chain Transgenic Mice Activate MRL-lpr/gldCD4+ T Cells
Authors: Beaudette-Zlatanova Britte C. , Ling Tina , Shlomchik Mark J. , Marshak-Rothstein Ann , Rifkin Ian R. 
Published: April 2014

AbstractAutoreactive CD4+ T cells are required for full expression of disease in human systemic lupus erythematosus and in spontaneous murine lupus. However, the Ag specificity of these CD4+ T cells remains largely unknown. Rheumatoid factor (RF) B cells function as highly efficient APCs by taking up immune complexes (IC) and presenting IC constituents to T cells. We hypothesized that Ag-specific CD4+ T cells in lupus-prone mice could be identified by stimulating the CD4+ T cells with RF B cells from AM14 RF BCR transgenic mice pulsed with IC containing lupus-associated autoantibodies and autoantigens. This approach identified several independent T cell lines that proliferated robustly in response to IC-pulsed spleen cells from the AM14 RF BCR transgenic mice. However, these T cells did not recognize an IC constituent. Instead, these T cells recognized a determinant dependent on the inheritance of the transgene-encoded Vκ8 L chain, most likely a neoantigen created by the insertion of the transgene into the genome. Additionally, although the precise nature of the neoantigen is not known, the T cells described in this report may provide a useful tool for examining the role of T cells in the RF autoantibody response.
Persistence and Function of Central and Effector Memory CD4+ T Cells following Infection with a Gastrointestinal Helminth
Authors: Zaph Colby , Rook Kathryn A. , Goldschmidt Michael , Mohrs Markus , Scott Phillip , Artis David 
Published: April 2014

AbstractImmunity in the gastrointestinal tract is important for resistance to many pathogens, but the memory T cells that mediate such immunity are poorly characterized. In this study, we show that following sterile cure of a primary infection with the gastrointestinal parasite Trichuris muris, memory CD4+ T cells persist in the draining mesenteric lymph node and protect mice against reinfection. The memory CD4+ T cells that developed were a heterogeneous population, consisting of both CD62Lhigh central memory T cells (TCM) and CD62Llow effector memory T cells (TEM) that were competent to produce the Th type 2 effector cytokine, IL-4. Unlike memory T cells that develop following exposure to several other pathogens, both CD4+ TCM and TEM populations persisted in the absence of chronic infection, and, critically, both populations were able to transfer protective immunity to naive recipients. CD62LhighCD4+ TCM were not apparent early after infection, but emerged following clearance of primary infection, suggesting that they may be derived from CD4+ TEM. Consistent with this theory, transfer of CD62LlowCD4+ TEM into naive recipients resulted in the development of a population of protective CD62LhighCD4+ TCM. Taken together, these studies show that distinct subsets of memory CD4+ T cells develop after infection with Trichuris, persist in the GALT, and mediate protective immunity to rechallenge.
Agonistic Monoclonal Antibody Against CD40 Receptor Decreases Lymphocyte Apoptosis and Improves Survival in Sepsis
Authors: Schwulst Steven J. , Grayson Mitchell H. , DiPasco Peter J. , Davis Christopher G. , Brahmbhatt Tejal S. , Ferguson Thomas A. , Hotchkiss Richard S. 
Published: April 2014

Abstract
Sepsis causes a marked apoptosis-induced depletion of lymphocytes. The degree of lymphocyte apoptosis during sepsis strongly correlates with survival. CD40, a member of the TNFR family, is expressed on APCs and has potent antiapoptotic activity. In this study we determined whether an agonistic Ab against CD40 could protect lymphocytes from sepsis-induced apoptosis. Secondly, we examined potential antiapoptotic mechanisms of the putative protection. Lastly, we aimed to determine whether anti-CD40 treatment could improve survival in sepsis. CD1 mice were made septic by the cecal ligation and puncture method and treated postoperatively with anti-CD40 Ab. Treatment with anti-CD40 completely abrogated sepsis-induced splenic B cell death and, surprisingly, decreased splenic and thymic T cell death as well (p &lt; 0.001). To investigate the mechanism of protection of anti-CD40 therapy on T cells, CD40 receptor expression was examined. As anticipated, the CD40 receptor was constitutively expressed on B cells, but, unexpectedly, splenic and thymic T cells were found to express CD40 receptor during sepsis. Furthermore, CD4+CD8− T cells were the predominant subtype of T cells expressing CD40 receptor during sepsis. Additionally, the antiapoptotic protein Bcl-xL was found to be markedly increased in splenic B and T cells as well as in thymic T cells after treatment with anti-CD40 Ab (p &lt; 0.0025). Lastly, mice that were made septic in a double injury model of sepsis had improved survival after treatment with anti-CD40 as compared with controls (p = 0.05). In conclusion, anti-CD40 treatment increases Bcl-xL, provides nearly complete protection against sepsis-induced lymphocyte apoptosis, and improves survival in sepsis.
IL-17 Plays an Important Role in the Development of Experimental Autoimmune Encephalomyelitis
Authors: Komiyama Yutaka , Nakae Susumu , Matsuki Taizo , Nambu Aya , Ishigame Harumichi , Kakuta Shigeru , Sudo Katsuko , Iwakura Yoichiro 
Published: April 2014

AbstractIL-17 is a proinflammatory cytokine that activates T cells and other immune cells to produce a variety of cytokines, chemokines, and cell adhesion molecules. This cytokine is augmented in the sera and/or tissues of patients with contact dermatitis, asthma, and rheumatoid arthritis. We previously demonstrated that IL-17 is involved in the development of autoimmune arthritis and contact, delayed, and airway hypersensitivity in mice. As the expression of IL-17 is also augmented in multiple sclerosis, we examined the involvement of this cytokine in these diseases using IL-17−/− murine disease models. We found that the development of experimental autoimmune encephalomyelitis (EAE), the rodent model of multiple sclerosis, was significantly suppressed in IL-17−/− mice; these animals exhibited delayed onset, reduced maximum severity scores, ameliorated histological changes, and early recovery. T cell sensitization against myelin oligodendrocyte glycoprotein was reduced in IL-17−/− mice upon sensitization. The major producer of IL-17 upon treatment with myelin digodendrocyte glycopritein was CD4+ T cells rather than CD8+ T cells, and adoptive transfer of IL-17−/− CD4+ T cells inefficiently induced EAE in recipient mice. Notably, IL-17-producing T cells were increased in IFN-γ−/− cells, while IFN-γ-producing cells were increased in IL-17−/− cells, suggesting that IL-17 and IFN-γ mutually regulate IFN-γ and IL-17 production. These observations indicate that IL-17 rather than IFN-γ plays a crucial role in the development of EAE.
Head Kidney-Derived Macrophages of Common Carp (Cyprinus carpio L.) Show Plasticity and Functional Polarization upon Differential Stimulation
Authors: Joerink Maaike , Ribeiro Carla M. S. , Stet René J. M. , Hermsen Trudi , Savelkoul Huub F. J. , Wiegertjes Geert F. 
Published: April 2014

Abstract
Cells from the myeloid lineage are pluripotent. To investigate the potential of myeloid cell polarization in a primitive vertebrate species, we phenotypically and functionally characterized myeloid cells of common carp (Cyprinus carpio L.) during culture. Flow cytometric analysis, Ab labeling of cell surface markers, and light microscopy showed the presence of a major population of heterogeneous macrophages after culture. These head kidney-derived macrophages can be considered the fish equivalent of bone marrow-derived macrophages and show the ability to phagocytose, produce radicals, and polarize into innate activated or alternatively activated macrophages. Macrophage polarization was based on differential activity of inducible NO synthase and arginase for innate and alternative activation, respectively. Correspondingly, gene expression profiling after stimulation with LPS or cAMP showed differential expression for most of the immune genes presently described for carp. The recently described novel Ig-like transcript 1 (NILT1) and the CXCR1 and CXCR2 chemokine receptors were up-regulated after stimulation with cAMP, an inducer of alternative activation in carp macrophages. Up-regulation of NILT1 was also seen during the later phase of a Trypanosoma carassii infection, where macrophages are primarily alternatively activated. However, NILT1 could not be up-regulated during a Trypanoplasma borreli infection, a model for innate activation. Our data suggest that NILT1, CXCR1, and CXCR2 could be considered markers for alternatively activated macrophages in fish.
Gender Differences in Murine Airway Responsiveness and Lipopolysaccharide-Induced Inflammation
Authors: Card Jeffrey W. , Carey Michelle A. , Bradbury J. Alyce , DeGraff Laura M. , Morgan Daniel L. , Moorman Michael P. , Flake Gordon P. , Zeldin Darryl C. 
Published: April 2014

Abstract
The roles of gender and sex hormones in lung function and disease are complex and not completely understood. The present study examined the influence of gender on lung function and respiratory mechanics in naive mice and on acute airway inflammation and hyperresponsiveness induced by intratracheal LPS administration. Basal lung function characteristics did not differ between naive males and females, but males demonstrated significantly greater airway responsiveness than females following aerosolized methacholine challenge as evidenced by increased respiratory system resistance and elastance (p &lt; 0.05). Following LPS administration, males developed more severe hypothermia and greater airway hyperresponsiveness than females (p &lt; 0.05). Inflammatory indices including bronchoalveolar lavage fluid total cells, neutrophils, and TNF-α content were greater in males than in females 6 h following LPS administration (p &lt; 0.05), whereas whole-lung TLR-4 protein levels did not differ among treatment groups, suggesting that differential expression of TLR-4 before or after LPS exposure did not underlie the observed inflammatory outcomes. Gonadectomy decreased airway inflammation in males but did not alter inflammation in females, whereas administration of exogenous testosterone to intact females increased their inflammatory responses to levels observed in intact males. LPS-induced airway hyperresponsiveness was also decreased in castrated males and was increased in females administered exogenous testosterone. Collectively, these data indicate that airway responsiveness in naive mice is influenced by gender, and that male mice have exaggerated airway inflammatory and functional responses to LPS compared with females. These gender differences are mediated, at least in part, by effects of androgens.
A Regulatory Effect of the Balance between TNF-α and IL-6 in the Granulomatous and Inflammatory Response to Rhodococcus aurantiacus Infection in Mice
Authors: Yimin  , Kohanawa Masashi 
Published: April 2014

Abstract
After i.v. inoculation with Rhodococcus aurantiacus, wild-type (WT) mice develop nonnecrotic, epithelioid granulomas. Because a high level of TNF-α is observed during the initial phase postinfection, we examined the extent to which TNF-α contributes to granulomatous inflammation using TNF-α gene-deficient (TNF-α−/−) mice. Despite a lack of R. aurantiacus proliferation, TNF-α−/− mice displayed high mortality rates within 5 days postinfection, as well as a high level of IL-6 in their spleens. Histological examination showed an absence of granuloma formation in TNF-α−/− mice. Pretreatment of TNF-α−/− mice with rTNF-α failed to restore this granuloma formation but accelerated bacterial removal and cellular recruitment. This rTNF-α administration also attenuated IL-6 production, resulting in increased survival rates of TNF-α−/− mice. Heat-killed R. aurantiacus induced in vitro enhanced mRNA expression and production of IL-6 in macrophages and DCs from TNF-α−/− mice when compared with WT controls, and treatment of TNF-α−/− mouse cells with rTNF-α decreased the IL-6 secretion. Moreover, anti-TNF-α or anti-IL-6 treatment increased IL-6 or TNF-α production by WT mouse cells, respectively. These data suggest that the production of TNF-α and IL-6 can be negatively regulated by each other. Administration of rIFN-γ to TNF-α−/− mice caused immature granulomas in livers, and treatment with both rTNF-α and rIFN-γ led to the formation of mature granulomas. Overall, TNF-α appears crucial for bacterial clearance, cellular recruitment, and granuloma formation. The balance between TNF-α and IL-6 during the early phase of infection controls the development of the inflammatory response to R. aurantiacus infection.
FcγRIIa, Not FcγRIIb, Is Constitutively and Functionally Expressed on Skin-Derived Human Mast Cells
Authors: Zhao Wei , Kepley Christopher L. , Morel Penelope A. , Okumoto Lawrence M. , Fukuoka Yoshihiro , Schwartz Lawrence B. 
Published: April 2014

Abstract
The expression of FcγR by human skin-derived mast cells of the MCTC type was determined in the current study. Expression of mRNA was analyzed with microarray gene chips and RT-PCR; protein by Western blotting and flow cytometry; function by release of β-hexosaminidase, PGD2, leukotriene C4 (LTC4), IL-5, IL-6, IL-13, GM-CSF, and TNF-α. FcγRIIa was consistently detected along with FcεRI at the mRNA and protein levels; FcγRIIc was sometimes detected only by RT-PCR; but FcγRIIb, FcγRI, and FcγRIII mRNA and protein were not detected. FcγRIIa-specific mAb caused skin MCTC cells to degranulate and secrete PGD2, LTC4, GM-CSF, IL-5, IL-6, IL-13, and TNF-α in a dose-dependent fashion. FcεRI-specific mAb caused similar amounts of each mediator to be released with the exception of LTC4, which was not released by this agonist. Simultaneous but independent cross-linking of FcεRI and FcγRIIa did not substantially alter mediator release above or below levels observed with each agent alone. Skin MCTC cells sensitized with dust-mite-specific IgE and IgG, when coaggregated by Der p2, exhibited enhanced degranulation compared with sensitization with either IgE or IgG alone. These results extend the known capabilities of human skin mast cells to respond to IgG as well as IgE-mediated signals.
Hierarchy of α Fetoprotein (AFP)-Specific T Cell Responses in Subjects with AFP-Positive Hepatocellular Cancer
Authors: Liu Yang , Daley Sean , Evdokimova Viktoria N. , Zdobinski David D. , Potter Douglas M. , Butterfield Lisa H. 
Published: April 2014

Abstract
We identified a series of immunodominant and subdominant epitopes from α fetoprotein (AFP), restricted by HLA-A*0201, which are recognized by the human T cell repertoire. The four immunodominant epitopes have been tested for immunogenicity in vivo, in HLA-A*0201+AFP+ advanced stage hepatocellular cancer (HCC) patients, and have activated and expanded AFP-specific IFN-γ-producing T cells in these patients, despite high serum levels of this self Ag. Here, we have examined the frequency, function, and avidity of the T cells specific for subdominant epitopes from AFP. We find that T cells specific for several of these epitopes are of similar or higher avidity than those specific for immunodominant epitopes. We then tested the peripheral blood of subjects ex vivo with different levels of serum AFP for the hierarchy of response to epitopes from this Ag and find that HCC patients have detectable frequencies of circulating IFN-γ-producing AFP-specific CD8+ T cells to both immunodominant and subdominant epitopes. We find the immunodominant and subdominant peptide-specific T cells to be differentially expanded with different modes of Ag presentation. Whereas spontaneous and AFP protein-stimulated responses show evidence for immunodominance, AdVhAFP-transduced dendritic cell-stimulated responses were broader and not skewed. Importantly, these data identify subdominant epitopes from AFP that can activate high-avidity T cells, and that can be detected and expanded in HCC subjects. These subdominant epitope-specific T cells can also recognize tumor cells and may be important therapeutically.
CD48 Is an Allergen and IL-3-Induced Activation Molecule on Eosinophils
Authors: Munitz Ariel , Bachelet Ido , Eliashar Ron , Khodoun Marat , Finkelman Fred D. , Rothenberg Marc E. , Levi-Schaffer Francesca 
Published: April 2014

Abstract
Eosinophils are involved in a variety of allergic, parasitic, malignant, and idiopathic disorders by releasing a variety of factors including specific granule proteins, lipid mediators, and proinflammatory and immunoregulatory cytokines and chemokines. In addition, they interact with various cell types in the inflamed tissue. Yet, the mechanism of eosinophil activation is still poorly understood. Recently, we described the expression and function of the CD2-subfamily of receptors and especially 2B4 on human eosinophils. In this study we focus on CD48, the high-affinity ligand of 2B4. CD48 is a GPI-anchored protein involved in cellular activation, costimulation, and adhesion, but has not been studied on eosinophils. We demonstrate that human eosinophils from atopic asthmatics display enhanced levels of CD48 expression and that IL-3 up-regulates CD48 expression. Furthermore, cross-linking CD48 on human eosinophils triggers release of eosinophil granule proteins. Assessment of CD48 expression in a murine model of experimental asthma revealed that CD48 is induced by allergen challenge and partially regulated by IL-3. Additionally, anti-IL-3 reduces CD48 expression and the degree of airway inflammation. Thus, CD48 is an IL-3-induced activating receptor on eosinophils, likely involved in promoting allergic inflammation.
Nucleic Acid-Sensing TLRs as Modifiers of Autoimmunity
Authors: Deane Jonathan A. , Bolland Silvia 
Published: April 2014

Abstract
The immune system requires precise regulation of activating and inhibitory signals so that it can mount effective responses against pathogens while ensuring tolerance to self-components. Some of the most potent activation signals are triggered by innate immune molecules, particularly those in the TLR family. Recent studies have shown that engagement of TLRs plays a significant role in both innate and adaptive immunity. This review focuses on the ways that TLR function might contribute to the etiology of lupus-like syndromes in the context of an autoimmune-prone environment. By considering the sources, localization, and expression of both nucleic acids and the molecules that bind them, we discuss several ways that innate immunity can play a role in the development of systemic autoimmunity.
Cutting Edge: CD4 Is the Receptor for the Tick Saliva Immunosuppressor, Salp15
Authors: Garg Renu , Juncadella Ignacio J. , Ramamoorthi Nandhini , Ashish  , Ananthanarayanan Shobana K. , Thomas Venetta , Rincón Mercedes , Krueger Joanna K. , Fikrig Erol , Yengo Christopher M. , Anguita Juan 
Published: April 2014

Abstract
Salp15 is an Ixodes scapularis salivary protein that inhibits CD4+ T cell activation through the repression of TCR ligation-triggered calcium fluxes and IL-2 production. We show in this study that Salp15 binds specifically to the CD4 coreceptor on mammalian host T cells. Salp15 specifically associates through its C-terminal residues with the outermost two extracellular domains of CD4. Upon binding to CD4, Salp15 inhibits the subsequent TCR ligation-induced T cell signaling at the earliest steps including tyrosine phosphorylation of the Src kinase Lck, downstream effector proteins, and lipid raft reorganization. These results provide a molecular basis to understanding the immunosuppressive activity of Salp15 and its specificity for CD4+ T cells.
Functional Dichotomy in CD40 Reciprocally Regulates Effector T Cell Functions
Authors: Murugaiyan Gopal , Agrawal Reena , Mishra Gyan C. , Mitra Debashis , Saha Bhaskar 
Published: April 2014

Abstract
Activation of T cells requires signals through Ag-specific TCR and costimulatory molecules such as CD40L. Although the use of defined tumor Ags for the induction of protective T cells met with limited success, the CD40-CD40L interaction that was proposed to induce antitumor T cells did not prevent tumor growth completely. Using a model for prostate tumor, a leading cause of tumor-induced mortality in men, we show that the failure is due to a novel functional dichotomy of CD40 whereby it self-limits its antitumor functions by inducing IL-10. IL-10 prevents the CD40-induced CTL and TNF-α and IL-12 production, Th1 skewing, and tumor regression. Priming mice with tumor lysate-pulsed IL-10-deficient dendritic cells (DCs) or wild-type DC plus anti-IL-10 Ab establishes antitumor memory T cells that can transfer the protection into syngenic nude mice. Infusion of Ag-pulsed IL-10-deficient but not wild-type DCs back into syngenic mice results in successful therapeutic autovaccination. Thus, we demonstrate the IL-10-sensitive antitumor T cell memory formulating a novel prophylactic and therapeutic principle.
GATA-3 Regulates the Development and Function of Invariant NKT Cells
Authors: Kim Peter J. , Pai Sung-Yun , Brigl Manfred , Besra Gurdyal S. , Gumperz Jenny , Ho I-Cheng 
Published: April 2014

Abstract
Although invariant NKT (iNKT) cells participate in many aspects of immune responses, the molecular mechanisms regulating their development, maturation, and activation are still poorly understood. GATA-3 is a T cell-specific transcription factor that is also expressed in iNKT cells. The critical role of GATA-3 in conventional αβ T cells has been well documented, but whether GATA-3 also regulates the development and function of iNKT cells is unknown. In the present study, we report that deficiency of GATA-3 results in cell-intrinsic defects in the thymic development and peripheral maturation of murine iNKT cells. In addition, GATA-3 is also required for survival, activation, and effector functions of this unique population of T cells. Our data also reveal a previously unidentified peripheral maturation step that is GATA-3 dependent.