bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bleomycin-Induced E Prostanoid Receptor Changes Alter Fibroblast Responses to Prostaglandin E2
Authors: Moore Bethany B. , Ballinger Megan N. , White Eric S. , Green Maranne E. , Herrygers Amy B. , Wilke Carol A. , Toews Galen B. , Peters-Golden Marc 
Published: April 2014

Abstract
Although PGE2 is a potent inhibitor of fibroblast function, PGE2 levels are paradoxically elevated in murine lungs undergoing fibrotic responses. Pulmonary fibroblasts from untreated mice expressed all four E prostanoid (EP) receptors for PGE2. However, following challenge with the fibrogenic agent, bleomycin, fibroblasts showed loss of EP2 expression. Lack of EP2 expression correlated with an inability of fibroblasts from bleomycin-treated mice to be inhibited by PGE2 in assays of proliferation or collagen synthesis and blunted cAMP elevations in response to PGE2. PGE2 was similarly unable to suppress proliferation or collagen synthesis in fibroblasts from EP2−/− mice despite expression of the other EP receptors. EP2−/−, but not EP1−/− or EP3−/− mice, showed exaggerated fibrotic responses to bleomycin administration in vivo as compared with wild-type controls. EP2 loss on fibroblasts was verified in a second model of pulmonary fibrosis using FITC. Our results for the first time link EP2 receptor loss on fibroblasts following fibrotic lung injury to altered suppression by PGE2 and thus identify a novel fibrogenic mechanism.
Hypermutation Rate Normalized by Chronological Time
Authors: Wang Clifford L. , Wabl Matthias 
Published: April 2014

Abstract
It is generally believed that in cells undergoing Ig somatic hypermutation, more cell divisions result in more mutations. This is because DNA synthesis and replication is thought to play roles in the known mechanisms–cytidine deamination and subsequent conversion to thymidine, uracil-DNA glycosylase-mediated repair, mismatch repair, and DNA synthesis by error-prone polymerases. In this study, we manipulated the number of cell generations by varying the rate at which cultures of a mouse cell line were replenished with fresh medium. We found that the frequency of mutants does not necessarily increase with the number of cell generations. On the contrary, a greater number of divisions can lead to a lower frequency of mutants, indicating that cell division is not a rate-limiting step in the hypermutation process. Thus, when comparing mutation rates, we suggest that rates are more appropriately expressed as mutations per day than per cell generation.
Multiple Products Derived from Two CCL4 Loci: High Incidence of a New Polymorphism in HIV+ Patients
Authors: Colobran Roger , Adreani Patricia , Ashhab Yaqoub , Llano Anuska , Esté José A. , Dominguez Orlando , Pujol-Borrell Ricardo , Juan Manel 
Published: April 2014

AbstractHuman CCL4/macrophage inflammatory protein (MIP)-1β and CCL3/MIP-1α are two highly related molecules that belong to a cluster of inflammatory CC chemokines located in chromosome 17. CCL4 and CCL3 were formed by duplication of a common ancestral gene, generating the SCYA4 and SCYA3 genes which, in turn, present a variable number of additional non-allelic copies (SCYA4L and SCYA3L1). In this study, we show that both CCL4 loci (SCYA4 and SCYA4L) are expressed and alternatively generate spliced variants lacking the second exon. In addition, we found that the SCYA4L locus is polymorphic and displays a second allelic variant (hereinafter SCYA4L2) with a nucleotide change in the intron 2 acceptor splice site compared with the one described originally (hereinafter SCYA4L1). Therefore, the pattern of SCYA4L2 transcripts is completely different from that of SCYA4L1, since SCYA4L2 uses several new acceptor splice sites and generates nine new mRNAs. Furthermore, we analyzed the contribution of each locus (SCYA4 and SCYA4L1/L2) to total CCL4 expression in human CD8 T cells by RT-amplified fragment length polymorphism and real-time PCR, and we found that L2 homozygous individuals (L2L2) only express half the levels of CCL4 compared with L1L1 individuals. The analysis of transcripts from the SCYA4L locus showed a lower level in L2 homozygous compared with L1 homozygous individuals (12% vs 52% of total CCL4 transcripts). A possible clinical relevance of these CCL4 allelic variants was suggested by the higher frequency of the L2 allele in a group of HIV+ individuals (n = 175) when compared with controls (n = 220, 28.6% vs 16.6% (p = 0.00016)).
Infection-Induced Marginal Zone B Cell Production of Borrelia hermsii-Specific Antibody Is Impaired in the Absence of CD1d
Authors: Belperron Alexia A. , Dailey Catherine M. , Bockenstedt Linda K. 
Published: April 2014

Abstract
Ab that arise in the absence of T cell help are a critical host defense against infection with the spirochetes Borrelia burgdorferi and Borrelia hermsii. We have previously shown that CD1d-deficient (CD1d−/−) mice have impaired resistance to infection with B. burgdorferi. In mice, CD1d expression is highest on marginal zone B (MZB) cells, which produce Ab to blood-borne Ag. In this study we examined MZB cell activation and Ab production in mice infected with B. hermsii, which achieve high levels of bacteremia. We show by flow cytometry that MZB cells associate with B. hermsii and up-regulate the activation markers syndecan I and B7.1 within 16 h of infection. By 24 h, MZB cells secrete B. hermsii-specific IgM, coinciding with the loss of activation marker expression and the reduction in spirochete burden. In contrast, MZB cells from CD1d−/− mice remain activated for at least 96 h of infection, but produce only minimal B. hermsii-specific IgM in vivo and ex vivo; pathogen burden in the blood also remains elevated. Wild-type mice depleted of MZB cells using mAb to LFA-1 and α4β1 integrin have reduced serum levels of B. hermsii-specific IgM and increased pathogen burden, similar to B. hermsii-infected CD1d−/− mice. Passive transfer of immune mouse serum, but not naive mouse serum, into infected CD1d−/− mice leads to down-regulation of activation markers and clearance of B. hermsii from the MZB cells. These results demonstrate that blood-borne spirochetes activate MZB cells to produce pathogen-specific IgM and reveal a role for CD1d in this process.
Mycobacteria Inhibition of IFN-γ Induced HLA-DR Gene Expression by Up-Regulating Histone Deacetylation at the Promoter Region in Human THP-1 Monocytic Cells
Authors: Wang Yue , Curry Heather M. , Zwilling Bruce S. , Lafuse William P. 
Published: April 2014

AbstractInfection of macrophages with mycobacteria has been shown to inhibit the macrophage response to IFN-γ. In the current study, we examined the effect of Mycobacteria avium, Mycobacteria tuberculosis, and TLR2 stimulation on IFN-γ-induced gene expression in human PMA-differentiated THP-1 monocytic cells. Mycobacterial infection inhibited IFN-γ-induced expression of HLA-DRα and HLA-DRβ mRNA and partially inhibited CIITA expression but did not affect expression of IFN regulatory factor-1 mRNA. To determine whether inhibition of histone deacetylase (HDAC) activity could rescue HLA-DR gene expression, butyric acid and MS-275, inhibitors of HDAC activity, were added at the time of M. avium or M. tuberculosis infection or TLR2 stimulation. HDAC inhibition restored the ability of these cells to express HLA-DRα and HLA-DRβ mRNA in response to IFN-γ. Histone acetylation induced by IFN-γ at the HLA-DRα promoter was repressed upon mycobacteria infection or TLR2 stimulation. HDAC gene expression was not affected by mycobacterial infection. However, mycobacterial infection or TLR2 stimulation up-regulated expression of mammalian Sin3A, a corepressor that is required for MHC class II repression by HDAC. Furthermore, we show that the mammalian Sin3A corepressor is associated with the HLA-DRα promoter in M. avium-infected THP-1 cells stimulated with IFN-γ. Thus, mycobacterial infection of human THP-1 cells specifically inhibits HLA-DR gene expression by a novel pathway that involves HDAC complex formation at the HLA-DR promoter, resulting in histone deacetylation and gene silencing.
Antibodies against Tumor Cell Glycolipids and Proteins, but Not Mucins, Mediate Complement-Dependent Cytotoxicity
Authors: Ragupathi Govind , Liu Nancy X. , Musselli Cristina , Powell Shemeeakah , Lloyd Kenneth , Livingston Philip O. 
Published: April 2014

Abstract
One of several effector mechanisms thought to contribute to Ab efficacy against cancer is complement-dependent cytotoxicity (CDC). Serological analysis of a series of clinical trials conducted over a 10-year period suggested that six vaccines containing different glycolipids induced Abs mediating CDC whereas four vaccines containing carbohydrate or peptide epitopes carried almost exclusively by mucin molecules induced Abs that did not mediate CDC. To explore this further, we have now compared cell surface reactivity using flow cytometry assays (FACS), complement-fixing ability, and CDC activity of a panel of mAbs and immune sera from these trials on the same two tumor cell lines. Abs against glycolipids GM2, globo H and Lewis Y, protein KSA (epithelial cell adhesion molecule, also known as EpCAM) and mucin Ags Tn, sialylated Tn, Thomsen Friedenreich (TF), and MUC1 all reacted comparably by FACS with tumor cells expressing these Ags. Compared with the strong complement binding and CDC with Abs against glycolipids and KSA, complement binding was diminished with Abs against mucin Ags and no CDC was detected. A major difference between these two groups of Ags is proximity to the cell membrane. Glycolipids and globular glycoproteins extend less than 100 Å from the cell membrane while mucins extend up to 5000 Å. Although complement activation at sites remote from the cell membrane has long been known as a mechanism for resistance from complement lysis in bacteria, it is identified here for the first time as a factor which may contribute to resistance from CDC against cancer cells.
Adaptive Immune Responses Are Dispensable for Isolated Lymphoid Follicle Formation: Antigen-Naive, Lymphotoxin-Sufficient B Lymphocytes Drive the Formation of Mature Isolated Lymphoid Follicles
Authors: McDonald Keely G. , McDonough Jacquelyn S. , Newberry Rodney D. 
Published: April 2014

Abstract
Isolated lymphoid follicles (ILFs) are recently appreciated members of the mucosal immune system. The architecture, composition, and inducible nature of these structures indicates that these structures are tertiary lymphoid structures. The process leading to the formation of tertiary lymphoid structures, lymphoid neogenesis, has been observed in a number of inflammatory and autoimmune conditions. Given this association, there is considerable interest in identifying the factors promoting lymphoid neogenesis, and understanding the steps in this process. Using murine ILF formation as a model, we have examined the roles of different cellular sources of lymphotoxin (LT) and the adaptive immune response in lymphoid neogenesis. In this study, we report that, although other cellular sources of LT may supplant B lymphocytes in the formation of immature ILFs (loosely organized clusters of B lymphocytes), LT-sufficient B lymphocytes are required for the progression of immature ILFs to mature ILFs (organized lymphoid aggregates with a follicle-associated epithelium). ILF formation occurs in the absence of T lymphocytes and Ag-specific B lymphocyte responses, and ILF B lymphocytes express elevated levels of LT in the absence of antigenic stimulation. Consistent with a role for chemokines inducing LT expression in Ag-naive B lymphocytes, and a chemokine-driven positive-feedback loop driving mature ILF formation, mature ILFs express elevated levels of B lymphocyte chemoattractant in the absence of Ag-specific B lymphocyte stimulation. These observations indicate that ILFs contain Ag-naive lymphocytes, and suggest that events occurring within ILFs shape subsequent immune responses mediated by these lymphocytes.
Complement Inhibitors Targeted to the Proximal Tubule Prevent Injury in Experimental Nephrotic Syndrome and Demonstrate a Key Role for C5b-9
Authors: He Chun , Imai Masaki , Song Hongbin , Quigg Richard J. , Tomlinson Stephen 
Published: April 2014

Abstract
In glomerular diseases of diverse etiologies, dysfunction of the glomerular barrier to protein passage results in proteinuria, and proteinuria is considered an independent risk factor that plays a direct role in inflammation, interstitial fibrosis, and renal failure. The mechanism by which proteinuria leads to nephrotoxic injury is unclear, but a role for complement in mediating interstitial damage appears likely. We describe a strategy for Ag-specific targeting of complement inhibitors using a single chain Ab fragment and show that complement inhibitors targeted to the tubular epithelium protect against tubulointerstitial injury and renal dysfunction in a rat model of puromycin-induced nephrosis. The targeting of systemically administered complement inhibitors markedly enhanced their efficacy and obviated the need to systemically inhibit complement, thus reducing the risk of compromising host defense and immune homeostasis. Targeted inhibition of complement activation by Crry, and of membrane attack complex (MAC) formation by CD59 was equally therapeutic, demonstrating that the MAC plays a key role in proteinuria-induced tubulointerstitial injury. CD59 activity was dependent on its being targeted to the site of complement activation, and this is the first report of specific inhibition of the MAC in vivo after systemic administration of inhibitor. The data establish the MAC is a valid target for pharmaceutical intervention in proteinuric disorders and provide an approach to investigate the role of the MAC in complement-dependent disease under clinically relevant conditions.
Efficient Recruitment of Lymphocytes in Inflamed Brain Venules Requires Expression of Cutaneous Lymphocyte Antigen and Fucosyltransferase-VII
Authors: Piccio Laura , Rossi Barbara , Colantonio Lucia , Grenningloh Roland , Gho Andrea , Ottoboni Linda , Homeister Jonathon W. , Scarpini Elio , Martinello Marianna , Laudanna Carlo , D’Ambrosio Daniele , Lowe John B. , Constantin Gabriela 
Published: April 2014

Abstract
Lymphocyte migration into the brain represents a critical event in the pathogenesis of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). However, the mechanisms controlling the recruitment of lymphocytes to the CNS via inflamed brain venules are poorly understood, and therapeutic approaches to inhibit this process are consequently few. In this study, we demonstrate for the first time that human and murine Th1 lymphocytes preferentially adhere to murine inflamed brain venules in an experimental model that mimics early inflammation during EAE. A virtually complete inhibition of rolling and arrest of Th1 cells in inflamed brain venules was observed with a blocking anti-P-selectin glycoprotein ligand 1 Ab and anti-E- and P-selectin Abs. Th1 lymphocytes produced from fucosyltransferase (FucT)-IV−/− mice efficiently tethered and rolled, whereas in contrast, primary adhesion of Th1 lymphocytes obtained from FucT-VII−/− or Fuc-VII−/−FucT-IV−/− mice was drastically reduced, indicating that FucT-VII is critical for the recruitment of Th1 cells in inflamed brain microcirculation. Importantly, we show that Abs directed against cutaneous lymphocyte Ag (CLA), a FucT-VII-dependent carbohydrate modification of P-selectin glycoprotein ligand 1, blocked rolling of Th1 cells. By exploiting a system that allowed us to obtain Th1 and Th2 cells with skin- vs gut-homing (CLA+ vs integrin β7+) phenotypes, we observed that induced expression of CLA on Th cells determined a striking increase of rolling efficiency in inflamed brain venules. These observations allow us to conclude that efficient recruitment of activated lymphocytes to the brain in the contexts mimicking EAE is controlled by FucT-VII and its cognate cell surface Ag CLA.
Defects in CD8+ Regulatory T Cells in the Lamina Propria of Patients with Inflammatory Bowel Disease
Authors: Brimnes Jens , Allez Matthieu , Dotan Iris , Shao Ling , Nakazawa Atsushi , Mayer Lloyd 
Published: April 2014

Abstract
Mucosal tolerance is believed to be partly mediated by regulatory T cells. Intestinal epithelial cells (IECs) may play an important role in the generation of such regulatory cells, because they are able to process and present Ag to T cells. Furthermore, we have previously demonstrated that IECs are able to generate regulatory CD8+ T cells in vitro. In the present study, we have analyzed lamina propria (LP) lymphocytes for the presence of such regulatory CD8+ T cells in normal individuals as well as in patients with inflammatory bowel disease (IBD). The results of the present study show that LP CD8+ T cells derived from normal controls possess regulatory activity, whereas both unfractionated LP lymphocytes and purified LP CD4+ T cells do not. The LP CD8+ T cells suppress Ig production by pokeweed mitogen-stimulated PBMCs by 31–80%, in a cell contact-dependent manner. No significant difference in suppression between CD28+ and CD28−CD8+ LP T cells was observed. In contrast to CD8+ T cells from normal LP, CD8+ T cells isolated from LP of IBD patients, did not suppress Ig production by pokeweed mitogen-stimulated PBMC (five of six ulcerative colitis specimens; six of six Crohn’s disease specimens). Furthermore, we demonstrate that the frequency of TCR Vβ5.1-positive CD8+ T cells, which we previously have demonstrated to be regulatory and to be expanded by IECs in vitro, is decreased in IBD LP compared with normal LP. In conclusion, this study demonstrates that CD8+ T cells with regulatory activity are present in the LP of normal healthy individuals, but not in patients with IBD, suggesting that these cells might play an active role in mucosal tolerance.
CXC Chemokine Ligand 12 (Stromal Cell-Derived Factor 1α) and CXCR4-Dependent Migration of CTLs toward Melanoma Cells in Organotypic Culture
Authors: Zhang Tianqian , Somasundaram Rajasekharan , Berencsi Klara , Caputo Laura , Rani Pyapalli , Guerry DuPont , Furth Emma , Rollins Barrett J. , Putt Mary , Gimotty Phyllis , Swoboda Rolf , Herlyn Meenhard , Herlyn Dorothee 
Published: April 2014

Abstract
Studies in experimental animal models have demonstrated that chemokines produced by tumor cells attract chemokine receptor-positive T lymphocytes into the tumor area, which may lead to tumor growth inhibition in vitro and in vivo. However, in cancer patients, the role of chemokines in T lymphocyte trafficking toward human tumor cells is relatively unexplored. In the present study, the role of chemokines and their receptors in the migration of a melanoma patient’s CTL toward autologous tumor cells has been studied in a novel organotypic melanoma culture, consisting of a bottom layer of collagen type I with embedded fibroblasts followed successively by a tumor cell layer, collagen/fibroblast separating layer, and, finally, a top layer of collagen with embedded fibroblasts and T cells. In this model, CTL migrated from the top layer through the separating layer toward tumor cells, resulting in tumor cell apoptosis. CTL migration was mediated by chemokine receptor CXCR4 expressed by the CTL and CXCL12 (stromal cell-derived factor 1α) secreted by tumor cells, as evidenced by blockage of CTL migration by Abs to CXCL12 or CXCR4, high concentrations of CXCL12 or small molecule CXCR4 antagonist. These studies, together with studies in mice indicating regression of CXCL12-transduced tumor cells, followed by regression of nontransduced challenge tumor cells, suggest that CXCL12 may be useful as an immunotherapeutic agent for cancer patients, when transduced into tumor cells, or fused to anti-tumor Ag Ab or tumor Ag.
Induction and Inhibition of the Th2 Phenotype Spread: Implications for Childhood Asthma
Authors: Hayashi Tomoko , Gong Xing , Rossetto Cyprian , Shen Carol , Takabayashi Kenji , Redecke Vanessa , Spiegelberg Hans , Broide David , Raz Eyal 
Published: April 2014

Abstract
The interactions between genetic and environmental factors play a major role in the development of childhood asthma. We hypothesized that a pre-existing Th2/asthmatic response can promote Th2 responses to newly encountered Ags (i.e., phenotype spread). To test this hypothesis, we developed a mouse model in which the requirements for the induction and inhibition of phenotype spread to a clinically relevant neo-allergen (i.e., ragweed) were investigated. Our results indicate that 1) phenotype spread to the neo-allergen can be induced only within the first 8 h after a bronchial challenge with the first Ag (OVA); 2) Th2 differentiation of naive CD4+ T cells occurs in bronchial lymph nodes; 3) trafficking of naive CD4+ T cells to local lymph nodes and IL-4 produced by OVA-activated Th2 cells play essential roles in the differentiation of naive CD4+ T cells to Th2 cells; and 4) suppression of the production of chemokines involved in the homing of naive CD4+ T and Th2 cells to bronchial lymph nodes by a TLR9 agonist inhibited phenotype spread and abrogated the consequent development of experimental asthma. These findings provide a mechanistic insight into Th2 phenotype spread and offer an animal model for testing relevant immunomodulatory interventions.
Chemical Xenobiotics and Mitochondrial Autoantigens in Primary Biliary Cirrhosis: Identification of Antibodies against a Common Environmental, Cosmetic, and Food Additive, 2-Octynoic Acid
Authors: Amano Katsushi , Leung Patrick S. C. , Rieger Roman , Quan Chao , Wang Xiaobing , Marik Jan , Suen Yat Fan , Kurth Mark J. , Nantz Michael H. , Ansari Aftab A. , Lam Kit S. , Zeniya Mikio , Matsuura Eiji , Coppel Ross L. , Gershwin M. Eric 
Published: April 2014

Abstract
Emerging evidence has suggested environmental factors as causative agents in the pathogenesis of primary biliary cirrhosis (PBC). We have hypothesized that in PBC the lipoyl domain of the immunodominant E2 component of pyruvate dehydrogenase (PDC-E2) is replaced by a chemical xenobiotic mimic, which is sufficient to break self-tolerance. To address this hypothesis, based upon our quantitative structure-activity relationship data, a total of 107 potential xenobiotic mimics were coupled to the lysine residue of the immunodominant 15 amino acid peptide of the PDC-E2 inner lipoyl domain and spotted on microarray slides. Sera from patients with PBC (n = 47), primary sclerosing cholangitis (n = 15), and healthy volunteers (n = 20) were assayed for Ig reactivity. PBC sera were subsequently absorbed with native lipoylated PDC-E2 peptide or a xenobiotically modified PDC-E2 peptide, and the remaining reactivity analyzed. Of the 107 xenobiotics, 33 had a significantly higher IgG reactivity against PBC sera compared with control sera. In addition, 9 of those 33 compounds were more reactive than the native lipoylated peptide. Following absorption, 8 of the 9 compounds demonstrated cross-reactivity with lipoic acid. One compound, 2-octynoic acid, was unique in both its quantitative structure-activity relationship analysis and reactivity. PBC patient sera demonstrated high Ig reactivity against 2-octynoic acid-PDC-E2 peptide. Not only does 2-octynoic acid have the potential to modify PDC-E2 in vivo but importantly it was/is widely used in the environment including perfumes, lipstick, and many common food flavorings.