bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unc119 Regulates Myofibroblast Differentiation through the Activation of Fyn and the p38 MAPK Pathway
Authors: Vepachedu Ramarao , Gorska Magdalena M. , Singhania Neil , Cosgrove Gregory P. , Brown Kevin K. , Alam Rafeul 
Published: April 2014

Abstract
Unc119 is an adaptor protein that is involved in the development of the vertebrate nervous system. We have shown that Unc119 stimulates the induction of α-smooth muscle actin (α-SMA) and myofibroblast differentiation by TGF-β in human lung fibroblasts. Unc119 increases the kinase activity of Fyn and associates with it in coprecipitation and colocalization studies. Phosphorylation and activation of Fyn in response to TGF-β and platelet-derived growth factor is delayed in Unc119-deficient cells. This delay translates into suppressed cell proliferation. In Src family kinase-deficient (SYF) cells, Unc119 knockdown does not affect cell proliferation. The result suggests that Unc119 interacts with Fyn in the early stages of signal generation and its presence is essential for conducive signal transduction. Unc119 overexpression does not stimulate α-SMA in SYF cells and this defect is restored upon reconstitution with Fyn indicating that Unc119 stimulation of α-SMA requires at least Fyn. Unc119 overexpression stimulated p38, but not JNK, phosphorylation. Blocking p38 MAPK resulted in reduced α-SMA expression by Unc119 suggesting that the p38 pathway regulates Unc119-induced myofibroblast differentiation. Unc119 stimulates the production of TGF-β and IL-6, known inducers of myofibroblast differentiation. Thus, Unc119 regulates receptor-mediated signal transduction and myofibroblast differentiation by activating Fyn and the p38 MAPK pathway. Using primary lung fibroblasts from patients with fibrotic lung diseases and control subjects, we show that the expression of α-smooth muscle actin is highly correlated with that of Unc119. Taken together, our results suggest that Unc119 plays an important role in fibrotic processes through myofibroblast differentiation.
TGF-β1 Regulates Antigen-Specific CD4+ T Cell Responses in the Periphery
Authors: Robinson Richard T. , Gorham James D. 
Published: April 2014

Abstract
T cell expansion typically is due to cognate interactions with specific Ag, although T cells can be experimentally activated through bystander mechanisms not involving specific Ag. TGF-β1 knockout mice exhibit a striking expansion of CD4+ T cells in the liver by 11 days of age, accompanied by CD4+ T cell-dependent necroinflammatory liver disease. To examine whether hepatic CD4+ T cell expansion in TGF-β1−/− mice is due to cognate TCR-peptide interactions, we used spectratype analysis to examine the diversity in TCR Vβ repertoires in peripheral CD4+ T cells. We reasoned that Ag-nonspecific T cell responses would yield spectratype profiles similar to those derived from control polyclonal T cell populations, whereas Ag-specific T cell responses would yield perturbed spectratype profiles. Spleen and liver CD4+ T cells from 11-day-old TGF-β1−/− mice characteristically exhibited highly perturbed nonpolyclonal distributions of TCR Vβ CDR3 lengths, indicative of Ag-driven T cell responses. We quantitatively assessed spectratype perturbation to derive a spectratype complexity score. Spectratype complexity scores were considerably higher for TGF-β1−/− CD4+ T cells than for TGF-β1+/− CD4+ T cells. TCR repertoire perturbations were apparent as early as postnatal day 3 and preceded both hepatic T cell expansion and liver damage. By contrast, TGF-β1−/− CD4+ single-positive thymocytes from 11-day-old mice exhibited normal unbiased spectratype profiles. These results indicate that CD4+ T cells in TGF-β1−/− mice are activated by and respond to self-Ags present in the periphery, and define a key role for TGF-β1 in the peripheral regulation of Ag-specific CD4+ T cell responses.
The Inositol 5′-Phosphatase SHIP-2 Negatively Regulates IgE-Induced Mast Cell Degranulation and Cytokine Production
Authors: Leung Wai-Hang , Bolland Silvia 
Published: April 2014

AbstractAggregation of the high-affinity IgE receptor (FcεRI) on mast cells initiates signaling pathways leading to degranulation and cytokine release. It has been reported that SHIP-1 negatively regulates FcεRI-triggered pathways but it is unknown whether its homologous protein SHIP-2 has the same function. We have used a lentiviral-based RNA interference technique to obtain SHIP-2 knockdown bone marrow-derived mast cells (BMMCs) and have found that elimination of SHIP-2 results in both increased mast cell degranulation and cytokine (IL-4 and IL-13) gene expression upon FcεRI stimulation. Elimination of SHIP-2 from BMMCs has no effect on FcεRI-triggered calcium flux, tyrosine phosphorylation of MAPKs or in actin depolymerization following activation. Rather, we observe that absence of SHIP-2 results in increased activation of the small GTPase Rac-1 and in enhanced microtubule polymerization upon FcεRI engagement. Coimmunoprecipitation experiments in rat basophilic leukemia (RBL 2H3) cells show that SHIP-2 interacts with the FcεRI β-chain, Gab2 and Lyn and that unlike SHIP-1, it does not associate with SHC in mast cells. Our results report a negative regulatory role of SHIP-2 on mast cell activation that is calcium independent and distinct from the regulation by SHIP-1.
Tolerance Induction in Presensitized Bone Marrow Recipients by Veto CTLs: Effective Deletion of Host Anti-Donor Memory Effector Cells
Authors: Reich-Zeliger Shlomit , Bachar-Lustig Esther , Bar-Ilan Avichai , Reisner Yair 
Published: April 2014

Abstract
Veto cells have been defined as cells capable of inducing apoptosis of effector CD8 cells recognizing their disparate MHC Ags. Tolerance induced by donor-type veto cells is desirable, because it is restricted to depletion of anti-donor clones without depletion of other immune specificities. It has been shown that anti-third party CTLs exhibit marked veto activity with reduced capacity to induce graft-vs-host disease, when tested on naive effector cells. However, presensitized T cells could play an important role in graft rejection, and therefore, their sensitivity to veto cells could be critical to the implementation of the latter cells in bone marrow transplantation. To address this question, we compared naive and presensitized TCR transgenic effector CD8 T cells, bearing a TCR against H-2d. Both cell types exhibited similar predisposition to killing by veto CTLs in vitro, and this killing was dependent in both cell types on Fas-FasL signaling as shown by using Fas-deficient CD8 T cells from (lprx2c) F1 mice. When tested in a stringent mouse model, in which bone marrow rejection is mediated by adoptively transferred host type T cells into lethally irradiated recipients, veto CTLs were equally effective in overcoming rejection of naive or presensitized host T cells.
Temporal and Spatial Changes of Histone 3 K4 Dimethylation at the IFN-γ Gene during Th1 and Th2 Cell Differentiation
Authors: Hamalainen-Laanaya Heli K. , Kobie James J. , Chang Chawnshang , Zeng Wei-ping 
Published: April 2014

Abstract
Covalent modification of nucleosomal histones is an important mechanism for cytokine gene regulation in Th1 and Th2 cells. In this study, we analyzed the kinetics of histone H3 K4 dimethylation (H3K4me2) of the IFN-γ gene. Minimal levels of H3K4me2 were found in naive CD4 T cells. After 5 days of differentiation, H3K4me2 levels were elevated in both Th1 and Th2 cells at the −5.3 kb, the promoter, the intronic DNase I hypersensitive sites, and 3′ distal sites including the +9.5 kb and +16 kb sites. Th1 cells maintained high levels of H3K4me2 after longer time of culture. However, in Th2 cells after 14 days, high levels of H3K4me2 were detected only at the −5.3 kb and the promoter, whereas H3K4me2 was lost at the 3′ distal sites and greatly diminished at the DNase I hypersensitive sites. After 28 days, Th2 cells lose H3K4me2 at all sites. Unlike the long-term primary Th2 cells, the Th2 clone D10 showed strong H3K4me2 at the IFN-γ gene with distinctly high levels at the 3′ distal sites. CD4 T cells transgenic for Hlx or infected with T-bet-expressing retrovirus produced IFN-γ and retained high levels of H3K4me2 even after differentiated under Th2 polarizing conditions, suggesting positive roles of these two factors in maintaining high levels of H3K4me2 at the IFN-γ gene.
The Activating Immunoreceptor NKG2D and Its Ligands Are Involved in Allograft Transplant Rejection
Authors: Kim Jim , Chang Catherine K. , Hayden Tracy , Liu Feng-Chun , Benjamin Jonathan , Hamerman Jessica A. , Lanier Lewis L. , Kang Sang-Mo 
Published: April 2014

Abstract
Although the linkage between innate and adaptive immunity in transplantation has been recognized, the mechanisms underlying this cooperation remain to be fully elucidated. In this study, we show that early “danger” signals associated with transplantation lead to rapid up-regulation of NKG2D ligands. A second wave of NKG2D ligand up-regulation is mediated by the adaptive immune response to allografts. Treatment with an Ab to NKG2D was highly effective in preventing CD28-independent rejection of cardiac allografts. Notably, NKG2D blockade did not deplete CD8+ T cells or NK1.1+ cells nor affect their migration to the allografts. These results establish a functional role of NKG2D and its ligands in the rejection of solid organ transplants.
Preferential Migration of T Regulatory Cells Induced by IL-16
Authors: McFadden Caroline , Morgan Ross , Rahangdale Shilpa , Green Daniel , Yamasaki Hisato , Center David , Cruikshank William 
Published: April 2014

Abstract
As a natural ligand for CD4, IL-16 has been shown to preferentially induce migration in Th1 cells, and, in long-term cultures with IL-2, IL-16 facilitates the expansion of CD4+CD25+ cells. In addition, IL-16 has an immunomodulatory role in asthmatic inflammation, as exogenous administration significantly reduces inflammation and airway hyperreactivity. The mechanism for this, however, is not clear. Based on its functional characteristics and potential immunomodulatory role, we investigated the ability of IL-16 to recruit and influence the development of T regulatory (Treg) cells. We now demonstrate that IL-16 preferentially induces migration in a CD25+CTLA-4+ human T cell subset and that responding cells produce IFNγ and TGFβ but not IL-10. These cells are relatively unresponsive to antigenic stimulation and can suppress proliferation and IL-5, but not IFNγ, production by autologous T cells. We further demonstrate that IL-16-recruited cells are enriched for Forkhead box P3 (Foxp3). In addition, we find that IL-16 stimulation may facilitate de novo induction of Foxp3+ Treg cells, because the stimulation of FoxP3-negative T cells for 48 h results in the expression of FoxP3 mRNA and protein. These data indicate that at sites of inflammation IL-16 may contribute to selective Treg cell expansion through the preferential induction of a migratory response from existing Treg cells, as well as by the induction of de novo generation of FoxP3+ cells. These findings offer a potential mechanism for the immunosuppressive effects of IL-16 seen in Th2-mediated inflammation.
Leflunomide Inhibits PDK1/Akt Pathway and Induces Apoptosis of Human Mast Cells
Authors: Sawamukai Norifumi , Saito Kazuyoshi , Yamaoka Kunihiro , Nakayamada Shingo , Ra Chisei , Tanaka Yoshiya 
Published: April 2014

Abstract
Mast cells release many inflammatory mediators that play an important role not only in allergic diseases but also in chronic inflammatory diseases, autoimmune diseases, and others. A lot of mast cells exist in synovium of rheumatoid arthritis, and it is known that synovitis does not occur in mast cell-deficient mice. Thus, it is thought that mast cells play a very important role in rheumatoid arthritis pathogenesis. Leflunomide is a drug used clinically in the treatment of rheumatoid arthritis. We used clinical doses of 2-cyano-3-hydroxy-N-(4-trifluoromethylphenyl)-butenamide (A77 1726), which is an active metabolite of leflunomide, and decreased the number of viable human primary mast cells in a concentration-dependent manner. This decrease was not reversed by uridine. Inhibition of pyrimidine synthesis by dihydro-orotic acid dehydrogenase inhibition, which is the primary mechanism of action of A77 1726, was not involved. A77 1726 dramatically induced apoptosis of human mast cells and inhibited the phosphorylation of Akt, an important survival signal of mast cells, in a concentration-dependent manner. Caspases 3 and 9, downstream molecules of Akt survival pathway, were also fragmented by A77 1726. In addition, it became evident for the first time that the mechanism involved in this result was the concentration-dependent inhibition of PDK1 phosphorylation, which controls the activation of Akt. These results indicate a new way of controlling mast cells and may therefore be the basis for innovative approaches to the treatment of various diseases related to mast cells.
Requirement for Both JAK-Mediated PI3K Signaling and ACT1/TRAF6/TAK1-Dependent NF-κB Activation by IL-17A in Enhancing Cytokine Expression in Human Airway Epithelial Cells
Authors: Huang Fei , Kao Cheng-Yuan , Wachi Shinichiro , Thai Philip , Ryu Jisu , Wu Reen 
Published: April 2014

AbstractThrough DNA microarray analysis and quantitative PCR verification, we have identified additional IL-17A-inducible genes—IL-19, CXCL-1, -2, -3, -5, and -6—in well-differentiated normal human bronchial epithelial cells. These genes, similar to previously described human β-defensin-2 (HBD-2) and CCL-20, were induced by a basolateral treatment of IL-17A, and regulated by PI3K signaling and NF-κB activation. For PI3K signaling, increases of cellular PIP3 and phosphorylation of downstream molecules, such as Akt and glycogen synthase kinase-3β (GSK3β) (S9), were detected. Induced gene expression and HBD-2 promoter activity were attenuated by LY294002, p110α small-interfering RNA (siRNA), as well as by an overexpression of constitutively active GSK3β(S9A) or wild-type phosphatase and tensin homolog. Increased phosphorylation of JAK1/2 after IL-17A treatment was detected in primary normal human bronchial epithelium cells. Transfected siRNAs of JAK molecules and JAK inhibitor I decreased IL-17A-induced gene expression and GSK3β(S9) phosphorylation. However, both JAK inhibitor I and PI3K inhibitor had no effect on the DNA-binding activities of p65 and p50 to NF-κB consensus sequences. This result suggested a JAK-associated PI3K signaling axis is independent from NF-κB activation. With siRNA to knockdown STIR (similar expression to fibroblast growth factor and IL-17R; Toll-IL-1R)-related signaling molecules, such as Act1, TNFR-associated factor 6 (TRAF6), and TGF-β-activated kinase 1 (TAK1), and transfection of A52R, an inhibitor of the MyD88/TRAF6 complex, or dominant-negative TAK1, IL-17A-inducible gene expression and HBD-2 promoter activity were reduced. Additionally, IL-17A-induced p65 and p50 NF-κB activations were confirmed and their nuclear translocations were down-regulated by siRNAs of TRAF6 and TAK1. These results suggest that two independent and indispensable signaling pathways—1) JAK1-associated PI3K signaling and 2) Act1/TRAF6/TAK1-mediated NF-κB activation—are stimulated by IL-17A to regulate gene induction in human airway epithelial cells.
Naive and Memory T Cells Induce Different Types of Graft-versus-Host Disease
Authors: Dutt Suparna , Tseng Diane , Ermann Joerg , George Tracy I. , Liu Yin Ping , Davis Corrine R. , Fathman C. Garrison , Strober Samuel 
Published: April 2014

Abstract
The goal of this study was to compare the ability of donor naive and alloantigen-primed effector memory T cells to induce graft-vs-host disease after bone marrow transplantation in MHC-mismatched irradiated host mice. Purified CD4+ naive (CD62LhighCD44low) T cells and CD4+ effector memory (CD62LlowCD44high) T cells obtained from unprimed donors and donors primed to host alloantigens, respectively, were injected into host mice, and the rapidity, severity, and pattern of tissue injury of graft-vs-host disease was assessed. Unexpectedly, the naive T cells induced a more acute and severe colitis than the primed memory cells. Whereas the naive T cells expressing CD62L and CCR7 lymph node homing receptors vigorously expanded in mesenteric lymph nodes and colon by day 6 after transplantation, the primed memory T cells without these receptors had 20- to 100-fold lower accumulation at this early time point. These differences were reflected in the significantly more rapid decline in survival and weight loss induced by naive T cells. The primed memory T cells had a greater capacity to induce chronic colitis and liver injury and secrete IL-2 and IFN-γ in response to alloantigenic stimulation compared with memory T cells from unprimed donors. Nevertheless, the expected increase in potency as compared with naive T cells was not observed due to differences in the pattern and kinetics of tissue injury.
Spontaneous Class Switch Recombination in B Cell Lymphopoiesis Generates Aberrant Switch Junctions and Is Increased after VDJ Rearrangement
Authors: Edry Efrat , Koralov Sergei B. , Rajewsky Klaus , Melamed Doron 
Published: April 2014

Abstract
Mature B cells replace the μ constant region of the H chain with a downstream isotype in a process of class switch recombination (CSR). Studies suggest that CSR induction is limited to activated mature B cells in the periphery. Recently, we have shown that CSR spontaneously occur in B lymphopoiesis. However, the mechanism and regulation of it have not been defined. In this study, we show that spontaneous CSR occurs at all stages of B cell development and generates aberrant joining of the switch junctions as revealed by: 1) increased load of somatic mutations around the CSR break points, 2) reduced sequence overlaps at the junctions, and 3) excessive switch region deletion. In addition, we found that incidence of spontaneous CSR is increased in cells carrying VDJ rearrangements. Our results reveal major differences between spontaneous CSR in developing B cells and CSR induced in mature B cells upon activation. These differences can be explained by deregulated expression or function of activation-induced cytidine deaminase early in B cell development.
Donor Bone Marrow Type II (Non-Vα14Jα18 CD1d-Restricted) NKT Cells Suppress Graft-Versus-Host Disease by Producing IFN-γ and IL-4
Authors: Kim Ji Hyung , Choi Eun Young , Chung Doo Hyun 
Published: April 2014

AbstractNKT cells in donor bone marrow (BM) have been demonstrated to protect against graft-vs-host disease (GVHD) following BM transplantation. Murine NKT cells are divided into two distinct subsets based on the invariant Vα14Jα18 TCR expression. However, details of the subset and mechanisms of the BM NKT cells involved in suppressing GVHD have not been clarified. Irradiated BALB/c or C3H/HeN mice administered B6 or Jα18−/− BM cells show attenuation of GVHD, whereas recipients given CD1d−/− BM cells did not show attenuation. Moreover, coinjection of BM non-Vα14Jα18 CD1d-restricted (type II) NKT cells and CD1d−/− BM cells suppressed GVHD, whereas coinjection of BM Vα14Jα18 TCR (type I) NKT cells did not. These protective effects on GVHD depended upon IFN-γ-producing type II NKT cells, which induced the apoptosis of donor T cells. The splenocytes of mice administered BM cells from B6.IL-4−/− or Jα18−/−IL-4−/− mice produced lower levels of IL-4 and IL-10 than the splenocytes of mice transplanted with BM cells from B6, B6.IFN-γ−/−, Jα18−/−, or Jα18−/−IFN-γ−/− mice. Taken together, our results show that IFN-γ-producing BM type II NKT cells suppress GVHD by inducing the apoptosis of donor T cells, while IL-4-producing BM type II NKT cells protect against GVHD by deviating the immune system toward a Th2-type response.
CD8 T Cell Help for Innate Antitumor Immunity
Authors: Shanker Anil , Verdeil Grégory , Buferne Michel , Inderberg-Suso Else-Marit , Puthier Denis , Joly Florence , Nguyen Catherine , Leserman Lee , Auphan-Anezin Nathalie , Schmitt-Verhulst Anne-Marie 
Published: April 2014

AbstractInnate immunity is considered to initiate adaptive antitumor responses. We demonstrate that monoclonal CD8 T lymphocytes reactive to tumor Ag P1A on P815 mastocytoma cells provide essential “help” to NK cells for rejection of P1A-deficient tumors. RAG-deficient mice have normal NK cells but do not reject either tumor. Reconstitution of these mice with P1A-specific T cells conferred resistance to both P1A-expressing and -deficient tumor cells provided they were present at the same site. Elimination of Ag-negative tumor variants required both activated T and NK cells. Gene expression profiling of NK cells infiltrating P1A-positive tumors in mice with specific CD8 T cells demonstrated an activated effector phenotype. However, CD8 T cell help to NK cells appeared ineffective for P1A-negative variants separated from the P1A-positive tumor. Local tumor Ag-specific T cell-NK cell collaboration results in the elimination of tumor cells whether they express or not the T cell tumor Ag epitope, thus containing the emergence of tumor escape variants before metastasis.
Primary Development and Participation in a Foreign Antigen-Driven Immune Response of a Chromatin-Reactive B Cell Clonotype Are Not Influenced by TLR9 or Other MyD88-Dependent TLRs
Authors: Coffey Francis , Liu Xiaohe , Manser Tim 
Published: April 2014

Abstract
Recent findings support a central role for TLRs in both foreign Ag-driven immune responses and systemic autoimmune diseases mediated by B lymphocytes. In vitro studies have shown that the Ag receptors (BCRs) on B cells specific for nuclear autoantigens can facilitate the delivery of these autoantigens to the endocytic compartment, resulting in activation of the nucleic acid-specific TLRs present in this subcellular locale. If this pathway is operative in vivo it might promote the development, survival, or activation of such autoreactive B cells. To test this idea, we evaluated the influence of a deficiency in the CpG DNA-specific TLR, TLR9, or all MyD88-dependent TLRs on the primary development and foreign Ag-driven immune response of B cells in a line of VH knockin mice that contains a high frequency of “dual reactive” B cells specific for DNA-based autoantigens such as chromatin, as well as the hapten arsonate. We found that although development and activation of these B cells in vitro are clearly influenced by DNA-based autoantigens, TLR9 or MyD88 deficiencies had no apparent effect on the primary development and participation in the anti-arsonate response of these B cells in vivo. We discuss these results in the context of previous models for the role of TLR9 and other TLRs in the regulation of antinuclear Ag B cell development and activity.